abrasive blasting guide
TRANSCRIPT
Abrasive Blasting Guide
Abrasive blasting will produce an effect that may combine both a cleaning and finishing action.
The finishing effect may vary by controlling such factors as hardness of the abrasive, abrasive
particle size, velocity of abrasive stream, angle of abrasive gun, distance from the work, method
of application and work flow.
As it is applied to preparation of surfaces prior to finishing, abrasive blasting is generally used to
replace sanding, wire brushing and pickling. Ordinarily, no other cleaning is necessary because
the blasted surface is chemically and mechanically cleaned.
Abrasive blasting can save from 25% to 75% of the time normally required by hand cleaning.
Blasting is considered economical. The abrasives are relatively inexpensive and reusable. The
general economical advantages of abrasive blasting lie in the reduction of man-hours required to
clean and finish parts and needing only minimally trained personnel, yet still having high
productivity per hour per dollar of equipment.
Abrasive blasting can make a good finish better and cleaner. It also produces a better tooth for
bonding. It is estimated that the surface area of metal increases as much as ten times as a result of
the abrasive impact action. This increases the surface to which paint, coating or plating can
adhere.
Pressure
Direct pressure machines require less pressure. Whereas a siphon machine is normally operated
at 60-90 PSI, the direct pressure machines can function at 15-80 PSI. Operating at lower pressure
reduces the work hardening of the surface and reduces warping of thin parts.
Most people sandblast at an air pressure that is too high. When you blast at pressures above 90
PSI, there is an excessive breakdown of the media and very little improvement of the cutting
rate.
The Sandblast Gun
Abrasive blasting is supposed to be a scrubbing action, not a peening process. Therefore, the gun
should always be aimed at a 60° to 45° angle to the surface being cleaned. When the gun is
aimed at 90°, peening occurs and, due to the abrasive particles colliding with the abrasive
bouncing off the surface, a very high rate of media wear occurs.
The gun in a siphon machine should be kept at least six inches from the surface being blasted.
This allows the spray to spread out and cover a larger area. Blasting a larger circle allows for
better overlap of the pattern and yields a more even and appealing finish. The direct pressure
units can effectively operate at distances of one foot or more.
The Gun Nozzle
Nozzles made of tungsten carbide are the best choice. Settling for a less expensive, lower quality
nozzle ultimately increases operational costs. If your compressor cannot keep up with the blaster,
chose a smaller nozzle for the gun. If you have plenty of pressure at the gauge, but don't seem to
feel it at the gun, look for an obstruction in the abrasive pickup line or something stuck in the
nozzle.
In a siphon machine, remember to change the air jet (behind the nozzle) every few nozzle
changes. A worn air jet will deflect the flow in the gun and cause the abrasive to wear a hole in
the side of the gun. If you have enough pressure at the gun, but very poor flow of abrasive, your
nozzle is worn, there is a hole in the siphon tube pick-up hose, or the abrasive is so fine that it
won't flow down to the pickup area.
The Hose
Replace the siphon hose on a regular basis. When the walls get too thin the hose will collapse
and obstruct the flow.
Media
Many types of finish may be obtained by the selection of abrasive and by the adjustment of air
pressure in the blasting unit. The more commonly used abrasives are
aluminum oxide,
white aluminum oxide,
urea and other plastic abrasives,
corn cob grit,
walnut shell grit,
glass beads,
pumice,
crushed glass grit,
silicon carbide,
steel grit and
steel shot.
For the most efficient performance, when the abrasive in the machine has broken down too
much, the entire load should be replaced. Adding new material to the old load greatly reduces the
performance of the abrasive and increases the amount of dust.
If you are getting a sporadic flow of abrasive, it is being caused by fine material not flowing
down to the pick-up area or too much pressure. Banging on the side of the cabinet hopper can
test this. If the flow is good after this, your material is too fine or may be moist.
MEDIA HINTS
Glass beads can be used to texturize, descale, or remove light burrs and die-cast flash
leaving a smooth bright satin finish. Used at 40 to 80 PSI.
Abrasive grits can be used for more aggressive work leaving a dull satin finish and are
useful for creating a good surface for bonding. Use up to 120 PSI.
Walnut shell grit can be used for deflashing thermoset plastics without destroying the
original polish. Use 30 to 80 PSI.
Grounding
Blasting machines occasionally cause shocks from static electricity. If the operator stands on a
mat grounded to the machine and the gun is grounded to the cabinet, this will be eliminated. The
cabinet can also be grounded to any conduit for insurance.
The Window
Try not to hold a part up to the window. This will cause frosting of the window and make it
difficult to see inside.
A scrap surcharge variance is in effect at the time of shipment. Please call for the current
surcharge. Learn more about the Steel Scrap Surcharge >>
Packaged in 5 lb jars, 10 lb jars, 25 lb pails, 50 lb pails, 55 lb bags & 55 gal drums.
Super sacks are also available upon request.
Glass beads are manufactured from lead-free, soda lime-type glass, containing no free silica that
is made into preformed ball shapes. Glass beads produce a much smoother and brighter finish
than angular abrasives. Glass beads can be recycled approximately 30 times. Chemically inert
and environmentally friendly, glass beads are an acceptable method of metal cleaning or surface
finishing when properly controlled.
Glass Bead Blasting
Glass bead blasting produces a clean, bright, satin finish, without dimensional change of the
parts. Available in a wide range of sizes, glass beads are primarily used in blasting cabinets for
honing, polishing, peening, blending, finishing, removing light burrs and cleaning most light
foreign matter. For delicate thin-walled parts and thin welds, peening with glass bead abrasive
material provides the right balance of stress relief without over-stressing and causing damage.
Consider the size of perforations or holes through which the glass beads must pass when screen
separating parts from media after use.
Size Description Mesh
#3 Extra Coarse 20/30
#4 #4 Grade 30/40
#5 #5 Grade 40/50
#6 Coarse 50/70
#8 Medium 70/100
#10 Medium-Fine 100/170
#13 Fine 170/325
Glass bead blasting media is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
Aluminum Oxide is a sharp, long-lasting abrasive sandblasting cutting media that can be re-used many times for grit blasting. As an abrasive blasting media, it is harder than most common dry abrasive blast media and will cut even the hardest metals and surfaces. This particular abrasive blasting media comes in a wide range of sizes.
White Aluminum Oxide is a 99.5% ultra-pure grade of blasting media. White Aluminum Oxide is increasingly being used in critical, high performance processes such as microdermabrasion. White Aluminum Oxide is also required where contamination from other metal oxides must be kept to a minimum.
Corn Cob is a biodegradable blast media that will not etch or warp surface being blasted. Ideal for applications such as wood log homes and thin metals and plastics.
Crushed Glass Grit is a silica-free consumable abrasive that offers aggressive surface profiling and
removal of a variety of coatings. Manufactured from 100% recycled bottle glass, Crushed Glass Grit produces a whiter, cleaner finish relative to mineral/slag abrasives.
Creating a softer, brighter finish than angular abrasives, Glass Beads offer a silica-free option for shot blasting, peening, honing, cleaning and light deburring. Glass Beads can be recycled up to 30 times.
Available in a variety of sizes, Urea, Acrylic, Polyester and Melamine Plastic Abrasives are ideal for applications such as auto restoration to deliver a high stripping rate without damage or warping of the substrate.
Pumice is the softest of all the blasting media yet still offers excellent stripping properties. Excellent for blasting surfaces such as soft wood to remove paint and coatings with no impact on the substrate.
Silicon Carbide is the hardest blasting media available. Silicon carbide has a very fast cutting speed and can be recycled and re-used many more times that either sand or aluminum oxide. The hardness of silicon carbide allows for much shorter blast times and lower overall cost per hour relative to other blast media.
Steel Grit is an angular carbon steel designed for quick and effective removal of surface contaminants from metals. Softer than Aluminum Oxide and less likely to fracture, Steel Grit leaves an etched surface superior for adhesion of paints and coatings.
Steel Shot is ideal for peening applications to impart a clean, smooth and polished finish. This dense, smooth shot can be used up to 3,000 times producing minimal dust during the blasting process increased compressive strength of the metal.
Walnut Shell Grit is the most versatile of the organic media due to its angular, durable shape yet is still considered a soft media. Use as an economical, biodegradable alternative for sensitive blasting operations that require aggressive stripping without effect on the substrate.
Walnut shell grit is the hard fibrous product made from ground or crushed walnut shells. When
used as a blasting media, walnut shell grit is extremely durable, angular and multi-faceted, yet is
considered a 'soft abrasive'. Walnut shell blasting grit is an excellent replacement for sand (free
silica) to avoid inhalation health concerns.
Cleaning by walnut shell blasting is particularly effective where the surface of the substrate
under its coat of paint, dirt, grease, scale, carbon, etc. should remain unchanged or otherwise
unimpaired. Walnut shell grit can be used as a soft aggregate in removing foreign matter or
coatings from surfaces without etching, scratching or marring cleaned areas.
When used with the right walnut shell blasting equipment, common blast cleaning applications
include stripping auto and truck panels, cleaning delicate molds, jewelry polishing, armatures
and electric motors prior to rewinding, deflashing plastics and watch polishing. When used as a
blast cleaning media, walnut shell grit removes paint, flash, burrs and other flaws in plastic and
rubber molding, aluminum and zinc die-casting and electronics industries. Walnut shell can
replace sand in paint removal, graffiti removal and general cleaning in restoration of buildings,
bridges and outdoor statuaries. Walnut shell is also used to clean aircraft engines and steam
turbines.
Description Mesh
Flour Grades
-325
-200
-100
60/100
40/100
Extra Fine 40/60
Fine 20/40
Medium 12/20
Coarse 8/12
Extra Coarse 4/6
Crushed walnut shell is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
As an angular, durable blasting abrasive, aluminum oxide (or aluminium oxide) can be recycled many times. It is the most widely used abrasive grain in sand blast finishing and surface preparation because of its cost, longevity and hardness. Harder than other commonly used blasting materials, aluminum oxide grit powder penetrates and cuts even the hardest metals and sintered carbide. Approximately 50% lighter than metallic media, aluminum oxide abrasive grain has twice as many particles per pound. The fast-cutting action minimizes damage to thin materials by eliminating surface stresses caused by heavier, slower cutting media. Aluminum oxide grit powder has a wide variety of applications, from cleaning engine heads, valves, pistons and turbine blades in the aircraft industry to lettering in monument and marker inscriptions. It is also commonly used for matte finishing, as well as cleaning and preparing parts for metalizing, plating and welding. Aluminum oxide abrasive grain is the best choice for an abrasive sand blasting and polishing grain as well as for preparing a surface for painting. As a premier aluminum oxide abrasive grain supplier, Kramer Industries recommends using virgin, brown aluminum oxide for optimal performance versus reprocessed or remanufactured product. Virgin, brown aluminum oxide contains less than 1.5% free silica and is therefore safer to use than sand. The grit size is consistent and cuts much faster than sand, leaving a smoother surface. Generally, the larger the grit size, the faster aluminum oxide will cut.
Abrasive Grit
Standard Mesh Sizes*
12
16
20
24
30
36
46
54
60
80
100
120
150
180
220
240
280
Grinding & Polishing
Powders
Standard Mesh Sizes*
320
360
400
500
600
800
1000
1200
*The smaller the mesh number, the coarser the grit.
Aluminum oxide tumbling media is packaged in
50 lb, 25 lb, 10 lb and 5 lb packages or 400 lb drums.
White aluminum oxide (or white aluminium oxide) grit is a 99.5% ultra pure grade of blasting media.
White aluminum oxide is increasingly being used in critical, high-performance microdermabrasion
equipment. The purity of this media along with the variety of grit sizes available make it ideal for both
traditional microdermabrasion processes as well as high-quality exfoliating creams.
White aluminum oxide is an extremely sharp, long-lasting blasting abrasive that can be recycled many
times after the initial media blasting. It is the most widely used abrasive in blast finishing and surface
preparation because of its cost, longevity and hardness. Harder than other commonly used blasting
materials, white aluminum oxide grains penetrate and cut even the hardest metals and sintered carbide.
Approximately 50% lighter than metallic media, white aluminum oxide has twice as many particles per
pound. The fast-cutting action minimizes damage to thin materials by eliminating surface stresses
caused by heavier, slower-cutting media blasting grits.
White aluminum oxide blasting media has a wide variety of applications, including cleaning engine
heads, valves, pistons and turbine blades in the aircraft and automotive industries. White aluminum
oxide is also an excellent choice for preparing a hard surface for painting.
White aluminum oxide contains less than 0.2% free silica and is therefore safer to use than sand. The
grit size is consistent and cuts much faster than other sand blasting media, leaving a smoother surface.
Abrasive Grit
Standard Mesh Sizes*
16
20
24
30
36
46
54
60
80
100
120
150
180
220
240
280
Grinding & Polishing
Powders
Standard Mesh Sizes*
320
360
400
500
600
800
1000
1200
*The smaller the mesh number, the coarser the grit.
White aluminum oxide blasting media is packaged in
50 lb, 25 lb, 10 lb and 5 lb packages or 400 lb drums.
Acrylic media is the longest lasting media on the market. It is very gentle
on the substrate and engineered for stripping the most sensitive surfaces
while providing an effective stripping rate. Acrylic media offers an
excellent range of stripping capabilities and is termed a multipurpose
media by its users. Standard mesh sizes 16-20, 20-30 and 30-40. Sizes 40-
60 and 60-80 can be specially ordered. Packaged in 5 lb jars, 10 lb pails,
25 pails, 50 lb boxes or bags and 250 lb drums.
Melamine is engineered for stripping the most difficult surfaces while
providing an effective stripping rate. Melamine is the most aggressive
plastic abrasive, offering an excellent range of stripping capabilities.
Melamine can be used as a replacement for glass beads and other harsh
abrasives. Standard mesh sizes 8-12, 10-20, 12-16, 16-20, 20-30, 30-40,
40-60 and 60-80. Sizes 12-20 and 20-40 can be specially ordered.
Packaged in 5 lb jars, 10 lb pails, 25 pails, 50 lb boxes or bags and 250 lb
drums.
Urea is a plastic grain stripping abrasive used in sandblasting operations. It
is the most widely used plastic media. Urea is environmentally friendly
and recyclable - an alternative to chemical stripping. Urea is formulated to
meet an increased level of stripping performance where stripping speed
outweighs other considerations. Urea is able to strip tough coatings with an
impressive strip rate. Urea is typically used for less sensitive applications.
Standard mesh sizes 8-12, 10-20, 12-16, 16-20, 20-30, 30-40, 40-60 and
60-80. Sizes 12-20 and 20-40 can be specially ordered. Packaged in 5 lb
jars, 10 lb pails, 25 pails, 50 lb boxes or bags and 250 lb drums.
Mesh Description
8-12 mesh / 1.70-2.36 mm
10-20 mesh / 0.85-2.00 mm
12-16 mesh / 1.20-1.70 mm
16-20 mesh / 0.85-1.20 mm
20-30 mesh / 0.56-0.85 mm
30-40 mesh / 0.42-0.56 mm
40-60 mesh / 0.25-0.42 mm
60-80 mesh / 0.16-0.25 mm
Plastic abrasives deliver a high stripping rate and consistent performance, ideal for paint
stripping, mold cleaning, deflashing and deburring.
Sandblasting, using compressed air, is traditionally used to prepare surfaces for coatings. The
sharp particles of aluminum oxide or other media abrade the surface. Incidental corrosion, rust,
and old coatings are removed in the process, leaving a good surface for paint adhesion.
However, substrates other than steel can often not tolerate this aggressive surface preparation
and, as a consequence, wet chemical strippers are employed to remove coatings. Aluminum,
brass and plastic composites, including fiberglass, are often treated in this way.
Using plastic abrasives has been proven to significantly reduce the generation of hazardous
waste that using wet chemical strippers can cause. In addition, the use of plastic abrasives has
proven to be faster, less damaging to the substrate and much less expensive than wet chemicals.
Since the plastic abrasive is harder than the coatings to be removed, yet softer than the substrate,
coatings can actually be stripped three or four times without damage to the surface.
Plastic abrasives are sensitive to substrates, including aluminum and other delicate metals,
composites and plastics, yet tough enough to take care of the most demanding decoating and
surface finishing needs efficiently.
Consider the size of perforations or holes through which the plastic abrasive must pass when
screen separating parts from media after use.
Recyclable. Call for details.
Applications include:
Rubber molds
Urethane bumpers
Aircraft engine components
Auto/bus/truck bodies
Helicopters
Tanks
Wheels
Surface sealants
Airframes
Aircraft components
Fiberglass components
Printed circuit boards
Semiconductors
Soft metals such as aluminum and magnesium
Carbon graphite composites
Axial lead diodes/capacitors/clear optical sensors
Computer housing panels
Copper armature wires
Metal die-castings
Steel
Gears
Tire Molds
Actuator assemblies
and more!
Corn cob blasting grit is a safe blasting media for delicate parts in addition to use as the preferred
blasting grit for log homes and other wood surfaces. Corn cob grit abrasive will remove surface
contamination, debris and coatings with little to no impact on the substrate.
Corn cob is a biodegradable, organic blasting media that is obtained from the hard woody ring of
the cob. It is resistant to break down and can be re-used multiple times in the blasting process.
Corn cob is available in a variety of grit sizes and presents no health or environmental hazards.
Virtually dust-free blasting with no sparking leaves a clean and dry surface.
Proper selection of corn cob grit size is important in blasting operations to balance
aggressiveness with desired results.
Description Mesh
Extra Coarse +8 Mesh (2.36 mm & larger)
Coarse 8-14 Mesh (2.36-1.40 mm)
10-14 Mesh (2.00-1.40 mm)
Medium 14-20 Mesh (1.40-0.85 mm)
Fine 20-40 Mesh (0.85-0.42 mm)
Extra Fine 40-60 Mesh (0.42-0.25 mm)
Flour -40 Mesh (0.42 mm & finer)
-60 Mesh (0.25 mm & finer)
Corn cob blasting media is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
Walnut shell grit is the hard fibrous product made from ground or crushed walnut shells. When
used as a blasting media, walnut shell grit is extremely durable, angular and multi-faceted, yet is
considered a 'soft abrasive'. Walnut shell blasting grit is an excellent replacement for sand (free
silica) to avoid inhalation health concerns.
Cleaning by walnut shell blasting is particularly effective where the surface of the substrate
under its coat of paint, dirt, grease, scale, carbon, etc. should remain unchanged or otherwise
unimpaired. Walnut shell grit can be used as a soft aggregate in removing foreign matter or
coatings from surfaces without etching, scratching or marring cleaned areas.
When used with the right walnut shell blasting equipment, common blast cleaning applications
include stripping auto and truck panels, cleaning delicate molds, jewelry polishing, armatures
and electric motors prior to rewinding, deflashing plastics and watch polishing. When used as a
blast cleaning media, walnut shell grit removes paint, flash, burrs and other flaws in plastic and
rubber molding, aluminum and zinc die-casting and electronics industries. Walnut shell can
replace sand in paint removal, graffiti removal and general cleaning in restoration of buildings,
bridges and outdoor statuaries. Walnut shell is also used to clean aircraft engines and steam
turbines.
Description Mesh
Flour Grades
-325
-200
-100
60/100
40/100
Extra Fine 40/60
Fine 20/40
Medium 12/20
Coarse 8/12
Extra Coarse 4/6
Crushed walnut shell is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
Glass beads are manufactured from lead-free, soda lime-type glass, containing no free silica that
is made into preformed ball shapes. Glass beads produce a much smoother and brighter finish
than angular abrasives. Glass beads can be recycled approximately 30 times. Chemically inert
and environmentally friendly, glass beads are an acceptable method of metal cleaning or surface
finishing when properly controlled.
Glass Bead Blasting
Glass bead blasting produces a clean, bright, satin finish, without dimensional change of the
parts. Available in a wide range of sizes, glass beads are primarily used in blasting cabinets for
honing, polishing, peening, blending, finishing, removing light burrs and cleaning most light
foreign matter. For delicate thin-walled parts and thin welds, peening with glass bead abrasive
material provides the right balance of stress relief without over-stressing and causing damage.
Consider the size of perforations or holes through which the glass beads must pass when screen
separating parts from media after use.
Size Description Mesh
#3 Extra Coarse 20/30
#4 #4 Grade 30/40
#5 #5 Grade 40/50
#6 Coarse 50/70
#8 Medium 70/100
#10 Medium-Fine 100/170
#13 Fine 170/325
Glass bead blasting media is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
Pumice is a natural mineral - volcanic ash formed by the solidification of lava that is permeated
with gas bubbles. Pumice powder is used chiefly as an abrasive and is among the softest of all
media. Use pumice powder for less aggressive operations where the protection of the surface is
of supreme importance. Pumice is the best media choice for tumbling plastics.
FFF, 01/2 and 3 grades are most popular and are standard stock items.
Typical Screen Analyses of Grades
US Standard Mesh
Percentages on each Mesh - note T = Trace
(less than 0.5 grams)
Grades
Size No Inches Opening Microns FFFF FFF FF 0 01/2
1/2 3 4
10 0.0787 2000
14 0.0555 1400 1-40
20 0.0331 850 25-55
30 0.0234 600 T-5 5-30
40 0.0165 425 20-60 5-30
50 0.0117 300 T-10 40-60 1-20
60 0.0098 250 1-10 10-30 T-5
80 0.0070 180 T-5 T-10 30-60 1-10
100 0.0059 150 T-5 1-10 20-35 T-5
120 0.0049 125 1-10 1-15 10-25
140 0.0041 106 1-15 10-30 1-10
170 0.0035 90 T-10 1-15 10-30
200 0.0029 75 T T-2 5-10 1-15 10-35
325 0.0017 45 10-20 10-25 10-25 10-25 20-40
Pan 80-90 75-90 70-80 40-70 1-10 T-5 T-10
Totals 100% 100% 100% 100% 100% 100% 100% 100%
Oil Absorption
(ASTM D281)
Actual 45 45 45 45 45 45 45 N/A
Saturation 45 45 45 45 45 75 105 N/A Apparent Bulk Density lbs/ft³ poured loose and leveled per
ASTM C29 as dry powder 48 47 45 44 37 34 29 28 Actual Oil Absorption is the number of pounds of oil per 100 pounds of pumice to completely coat the particle surface. Saturation Oil Absorption
is the number of pounds of oil per 100 pounds of pumice to completely fill the voids between particles.
Pumice blasting media is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
KramBlast Crushed Glass Grit is manufactured from 100% post-consumer, recycled bottle glass.
This glass grit delivers superior performance relative to mineral/slag abrasives. KramBlast
Crushed Glass Grit contains no free silica, is non-toxic and inert and contains no heavy metals
typically found in coal and copper slags. All of the feed-stock material is sent through a state-of-
the-art magnetic separating system to remove any contamination and unwanted particulate. This
is followed by multiple screening processes to provide un-equaled ‘raw material’ for the final
cleaning and grading steps.
KramBlast Crushed Glass Grit is cleaned using a proprietary flashing process to separate paper
and plastic from the glass. Making sure that the paper and plastic is not burned onto the glass
provides a cleaner, higher quality product ready for optimal performance. At this point, the glass
has an extremely low moisture content and a cleanliness level that far exceed the industry
standard.
A continuous screening process is used to create the various grades of KramBlast Crushed Glass
Grit. This continuous process allows for the on-site screening operation to maintain quality
control and consistency of the various grades of media. Screens are checked on a regular basis
and restored to original specifications immediately. The 80,000 square foot facility provides
plenty of room for clean, dry storage of the product prior to shipping.
Blasting with KramBlast Crushed Glass Grit
The angular particles in crushed glass allow for aggressive surface profiling and removal of
coatings such as epoxy, paint, alkyds, vinyl, polyurea, coal tar and elastomers. KramBlast
Crushed Glass Grit is lighter weight than many slags, allowing for increased consumption
efficiency and production time – up to 30-50% less glass grit used. Crushed glass delivers very
low particle embedment, which produces a whiter, cleaner finish. Similar to many slags, crushed
glass grit has a hardness of 5.0 – 6.0 on the Moh’s Hardness Scale.
KramBlast Crushed Glass Grit and the Environment
Since KramBlast Crushed Glass Grit is manufactured from recycled bottle glass, it contains no
free silica which is commonly found in blasting sand. The use of post-consumer glass directly
benefits the environment by diverting waste from landfills. KramBlast Crushed Glass Grit is free
of heavy metals such as arsenic, lead, asbestos, beryllium, titanium, etc., all typically found in
coal and mineral slags.
Grade Mesh
Extra Coarse 8-12
Coarse 12-30
Medium 30-70
Fine -80
*The smaller the mesh number, the coarser the grit.
KramBlast is packaged in 50 lb, 25 lb, 10 lb and 5 lb packages.
Crushed glass has been added to the Qualified Products List by the US Navy. Crushed glass is
qualified under MIL-A-22262-B, Amendment-2 - Abrasive Blasting Media Ship Hull, Blast
Cleaning. Based on toxicological safety evaluations by the Naval Environmental Health Center
(NEHC), could be safely used for its intended purpose.
Silicon carbide is the hardest blasting media available. High-quality silicon carbide media is
manufactured to a blocky grain shape that splinters. The resulting silicon carbide abrasives have
sharp edges for blasting. Silicon carbide has a very fast cutting speed and can be recycled and
reused many more times than sand. The hardness of silicon carbide allows for much shorter blast
times relative to softer blast media.
Silicon carbide grit is the ideal media for use on glass and stone in both suction or siphon and
direct pressure blast systems. The ability to be recycled multiple times results in a cost-effective
silicon carbide grit blast media with optimal etching results.
Since silicon carbide grit is harder than aluminum oxide, it can be used efficiently for glass
engraving and stone etching. Silicon carbide grit blast media has no free silica, does not generate
static electricity and is manufactured to contain minimal magnetic content.
Abrasive Grit
Standard Mesh Sizes*
16
20
24
30
36
46
54
60
80
100
120
150
180
220
240
280
Grinding & Polishing
Powders
Standard Mesh Sizes*
320
360
400
500
600
800
1000
1200
*The smaller the mesh number, the coarser the grit.
Silicon carbide tumbling media is packaged in
50 lb, 25 lb, 10 lb and 5 lb packages or 330 lb drums.
Steel grit blasting is ideal for aggressive cleaning applications. Steel grit will quickly strip many types of
surface contaminants from steel and other foundry metals. Steel grit is softer than aluminum oxide and
does not fracture as easily, making it ideal for aircraft and aero-space applications. The angular nature of
steel grit produces an etched surface on metal for superior adhesion of paint, epoxy, enamel, rubber
and other coatings.
Different chemistries will lead to different operating results, depending on the size and hardness of the
grit. Since Kramer is a primary steel grit supplier, multiple chemistries of steel grit are available. Steel grit
that is formulated as a softer (40-50 HRC) metal will round off rapidly, making it ideal for quick stripping
of oxides and cleaning of molds. Harder steel grit (55-65 HRC) will maintain the angular nature of the grit
to provide continuous cutting action.
Grit Size Approximate
Size Finish Produced
G-14 0.055"
Deep etch rough G-16 0.046"
G-18 0.039"
G-25 0.023" Sharp etch
G-32 0.021"
G-40 0.017"
Medium etch G-50 0.011"
G-80 0.007"
Size All material is screened to meet or exceed SAE and SFS specifications.
Chemistry
Carbon: > 0.80% (depends on hardness) Sulfur: < 0.05%
Phosphorous: < 0.05%
Minimum
Density 7.3 g/cc (445 lbs/ft
3)
Bulk
Density 230 - 260 lbs/ft
3
Hardness Available
GP: 40-51 HRC GB: 47-56 HRC
GL: 54-61 HRC
GH: 60+ HRC
*If not specified, the default hardness for Steel Grit is GP (40-51 HRC). Please specify the
hardness required when placing an order.
Blasting Media Selection Guide
It is important to know the differences in blasting media, since different abrasive blasting media are
required for different applications. Blasting media can be used for purposes such as cleaning, stripping,
etching, strengthening and polishing. In addition to the media type, grit or mesh size is another factor to
consider for your application. The final choice of media depends on the nature of the work required and
on the blasting equipment that is employed. The blasting media selection guide below contains a list of
the common blasting media and the differences in blasting media.
Aluminum Oxide
Aluminum oxide is the most widely used abrasive in blast finishing and surface preparation Aluminum
oxide is an extremely sharp, long-lasting blasting abrasive that can be recycled many times. In addition
to the standard brown, aluminum oxide is available in 99.5% pure white grades. Hardness 8-9; Grit size
range 12-220; Angular shape. Compare
Crushed Glass Grit
The angular nature of crushed glass grit allows for aggressive surface profiling and removal of coatings
and surface contamination. Crushed glass grit contains no free silica, is non-toxic and inert and contains
no heavy metals typically found in coal and copper slags. Since crushed glass grit is lighter than many
slags up to 50% less media can be used. Hardness 5-6; Grit size range Coarse to Extra Fine; Angular
shape; Consumable. Compare
Glass Beads
Manufactured from lead-free, soda lime-type glass, containing no free silica, glass beads are
manufactured into preformed ball shapes. Glass beads produce a much smoother and brighter finish
than angular abrasives. Glass beads can be recycled approximately 30 times. Hardness 5-6; Grit size
range 50-325; Round shape. Compare
Silicon Carbide
As the hardest blasting media available, silicon carbide is has a very fast cutting speed. Manufactured to
a blocky grain shape that splinters, silicon carbide grit can be recycled many more times that other
blasting media. The hardness of silicon carbide is ideal for etching of glass and stone. Hardness 9-9.5;
Grit size range 16-240; Angular shape. Compare
Plastic Abrasive
Plastic abrasives are available in a variety of types that deliver quick stripping rates and consistent
performance. This media is ideal for stripping coatings and paint from substrates, including aluminum
and other delicate metals, composites and plastics. The relative softness of plastic abrasive media makes
it ideal for automotive and aerospace blasting applications. Hardness 3-4; Grit size range 12-80; Soft,
angular shape; Urea, Melamine, Acrylic compositions. Compare
Pumice
Pumice is a light, natural mineral that is used chiefly as a mild abrasive. Pumice is ideal for less
aggressive operations where protection of the surface is of supreme importance. Hardness 6-7; Grit size
range 14-325+ Compare
Steel Shot
Blasting with steel shot is a popular method for cleaning, stripping and improving a metal surface. Steel
shot is manufactured into a round ball shape that results in a smooth and polished surface. The peening
action of the steel shot produces improved compressive strength to metal surfaces. Hardness 40-51
HRC; Grit size range S-70 to S-780; Spherical shape. Compare
Steel Grit
High-demand, aggressive applications are ideal for steel grit. Steel grit offers a very fast stripping action
for many types of surface contaminants from steel and other foundry metals. Softer than aluminum
oxide but still angular in shape, steel grit will not fracture as easily making it perfect for creating an
etched surface on metal. Hardness 40-65 HRC; Grit size range G-12 to G-80; Angular shape. Compare
Corn Cob
Corn cob is an organic, soft blasting grit that is safe for delicate parts and soft substrates. As the
preferred blasting media for log homes and other wood surfaces, corn cob offers excellent cleaning and
stripping properties without damage to the substrate. Hardness 4-4.5; Grit size range Extra Coarse to
Extra Fine; Ground, Angular shape. Compare
Walnut Shell
Walnut shell grit is used for applications that require aggressive stripping or cleaning without damage or
effect on the underlying substrate. Organic and biodegradable, walnut shell is extremely durable,
angular in shape but is considered a soft abrasive. Walnut shell sees utility in applications such as
cleaning hard woods and aircraft and automotive stripping. Hardness 4.5-5; Grit size range Extra Coarse
to Extra Fine; Angular shape. Compare
Blasting Media Comparison Chart
Aluminum Oxide Crushed Glass
Grit Glass Beads Silicon Carbide
Plastic
Abrasives
Description
Sharp, long
lasting media for
fast etching &
profiling;
Brown/black or
White
Silica-free,
100% recycled
glass; Efficient,
economical
stripping
Round, soda-
lime glass to
produce a
bright, satin
finish;
Minimizes
stress on part
Very hard,
aggressive
cutting media;
Ideal for stone,
glass and hard
surfaces
Abrasive, soft
media designed
for automotive
& aerospace
applications
Surface
Profile High etch
Medium-high
etch
No etch, satin
finish Very high etch
No etch,
stripping
Working
Speed Fast Fast
Medium-
fast Very fast Medium
Recyclability High None;
consumable High High High
Surface
Removal Yes Slight Slight Yes Slight
Hardness,
Moh 8 - 9 5 - 6 5 - 6 9 - 9.5 3 - 4
Bulk Density 110 lbs/ft³ 100 lbs/ft³ 95 lbs/ft³ 90 lbs/ft³ 50 lbs/ft³
Pumice Steel Shot Steel Grit Corn Cob Walnut Shells
Description
Natural volcanic
ash; light-
weight, mild
abrasiveness
Carbon steel,
round spheres
designed for
polishing and
peening
applications
Angular,
carbon steel for
fast stripping &
aggressive
cleaning
Organic, soft
media ideal
for soft
surfaces such
as wood
Angular, organic
grit for mildly
aggressive
stripping w/out
damage to
surface
Surface
Profile Low etch No etch High etch None Low etch
Working
Speed
Medium-
slow Medium
Medium-
fast Slow
Medium-
slow
Recyclability Low Very high Very high Low Low
Surface
Removal No No Moderate No Very slight
Hardness,
Moh 6 – 7 40-51 HRC 40-65 HRC 4 - 4.5 4.5 – 5
Bulk Density 35-40 lbs/ft³ 230 lbs/ft³ 260 lbs/ft³ 40 lbs/ft³ 50 lbs/ft³
Abrasive Blasting Media Guide
The selection of finishes are virtually unlimited and so are the applications. The information
below is intended as a general reference guide. Consult Metal Preparations Company for
specific media applications.
Finishing Cleaning & Removal Surface Treatment & Preparation
Add matte or satin
finish, or decorative
frost Remove glare or
imperfections Blend marks Hone and burnish Mark identifications
Chemical
impurities Coatings Paint Sealants and
adhesives Carbon deposits Scale Excess brazing Casting materials Flashing Burrs Rust Oxidation
Strengthen Add fatigue resistance Improve wear properties Reduce design weights, porosity,
friction or susceptibilty to
corrosion Improve lubrication Expose flaws for inspection Etch for bonding and adhesion Cut
Media Guide
Glass
Bead Ceram
ic Shot
Stainle
ss Cut
Wire
Steel Sh
ot Steel G
rit Aluminu
m Oxide
Silico
n
Carbi
de
Garnet
Crush
ed
Glass
Plasti
c
Medi
a
Agri
Shell
Finishing Yes Yes Yes Yes Yes Yes Yes Yes Yes No No
Cleaning/Remo
val Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Peening Yes Yes Yes Yes No No No No No No No
Surfance No No Yes No Yes Yes Yes Yes Yes Yes Yes
Profiling (Etch)
Working Speed Med Med Med Med Med
High High
Very
High High High
Med
High Low
High
Recyclability Med
-
Low High High
Very
High Very
High Med-
High Med
Low Med
Med
Low Med Low
Probability of
Metal Removal Very
Low Very
Low Very
Low Very
Low Med
Med-
High Med
High Med
Low
Med Very
Low Very
Low
Hardness, MOH
Scale 5.5 7 6 - 7.5 6 - 7.5 8-9 8-9 9 8 5.5 3-4 1-4.5
(Rockwell RC) (57-
63) (35-55) (20-66) (40-66)
Bulk Density
(lb/cu. Ft.) 100 150 280 280 230 125 95 130 100
45-
60 40-80
Mesh Size 30-
440 8-46 20-62 8-200 10-325 12-325
36-
220 16-325
30-
400 12-
80 MAN
Y
Typical Blast
Pressures (psi) 20-55 20-90 20-90 20-90 20-90 20-90 20-90 30-80 20-50
20-
60 10-40
Nozzle Air and Pressure Requirements
Nozzle Pressure PSI Nozzle Orifice Air, Power, and Abrasive Requirements 50 60 70 80 90 100 125
1/8 inch Air (cu ft/min) 12 13 15 18 19 21 26
Horsepower (hp) 1.75 2 2.5 3 3.5 4 6 Abrasive (lb/hr) 70 80 90 100 110 120 135
3/16 inch Air (cu ft/min) 25 30 35 40 43 45 60
Horsepower (hp) 5 8 9 9.5 10 10.5 16 Abrasive (lb/hr) 150 170 200 215 240 260 320
1/4 inch Air (cu ft/min) 50 55 60 70 75 80 95
Horsepower (hp) 10 12 13 16 17 18 25 Abrasive (lb/hr) 270 300 350 400 450 500 675
5/16 inch Air (cu ft/min) 80 900 100 115 125 140 190
Horsepower (hp) 17 20 25 27 28 30 36 Abrasive (lb/hr) 470 530 600 675 750 200 275
3/8 inch Air (cu ft/min) 110 150 145 160 175 200 275
Horsepower (hp) 25 29 32 35 40 45 57 Abrasive (lb/hr) 675 775 845 975 1060 1100 1350
7/16 inch Air (cu ft/min) 150 170 200 215 240 255 315
Horsepower (hp) 35 40 45 50 55 60 70 Abrasive (lb/hr) 900 1000 1200 1300 1400 1550 1800
1/2 inch Air (cu ft/min) 200 225 250 275 300 340 430
Horsepower (hp) 45 50 55 63 70 75 95 Abrasive (lb/hr) 1200 1350 1500 1700 1850 2025 2525
5/8 inch Air (cu ft/min) 300 350 400 450 500 550 700
Horsepower (hp) 70 80 90 100 110 120 150 Abrasive (lb/hr) 1900 2200 2400 2700 3000 3300 4000
3/4 inch Air (cu ft/min) 430 500 575 650 700 800 1100
Horsepower (hp) 100 115 130 145 160 175 215 Abrasive (lb/hr) 2700 3100 3500 3900 4300 4700 5700
Abrasive selection is key to a successful coating job. The surface effects produced with various
abrasives can range from deep cutting to gentle scouring of the surface. Important factors to
consider in selecting an abrasive include
Type of surface to be cleaned
Shape of the structure
Type of material to be removed
Profile, breakdown rate of the abrasive
Hazards associated with the use of the abrasive
Potential damage to equipment located in the repair area
Abrasives commonly used for stripping include steel grit, aluminum oxide, garnet, and glass
beads. Steel grit creates a rough surface profile on the substrate that aids coating adhesion.
Because it is so hard and durable, steel grit can be reused, and it generates the least amount of
waste per unit of surface area stripped. To maximize the reuse of steel grit, companies must keep
the blast media dry to avoid rusting. Aluminum oxides are considered to be a multipurpose
material that is less aggressive and less durable than steel grit, and it results in a smoother surface
profile and less removal of substrate material. Garnet and glass beads are the least aggressive
abrasive and often are used in a single-pass operation (i.e., the abrasive is not recycled). Use of
garnet and glass beads is most suitable for preparation of soft materials that are easily damaged,
and for maintenance of the dimensional tolerance of the part.
Companies can use abrasive blasting to remove
paint and corrosion products from larger metal
structures in the field (field stripping) or from
smaller metal structures in a hanger, booth, or
blasting cabinet.
Outdoor blasting can be performed in an open
area. Operators must wear self-contained breathing
equipment in order to be protected from the
stripping dust. After blasting, the used abrasive
can be shoveled or vacuumed from the area and
processed through the reclaimer. Some systems
combine dust control and abrasive recovery by
including a vacuum collection pickup device with
the blasting nozzle. Abrasive blasting in cabinets
is often performed using manual blast cabinets and automated blasting chambers to remove paint
Moh’s Hardness Scale for Abrasive Media
Walnut Shells 2.5-4.5
Clear-Cut 2.0-2.5
Polyester Type I 3
Urea Type II 5
Melamine Type III 4
Glass Beads 5.0-6.5
Silica Sand (Quartz) 8
Garnet 10
Zirconia 11
Aluminum Oxide 12
Silicon Carbide 13
from parts. The abrasive is fed into the cabinet or chamber and directed against the part being
stripped. Used abrasive and removed paint are then pneumatically conveyed to a reclaimer.
Reusable abrasive is separated from the waste and fines (broken-down abrasives and paint chips)
are collected in a dust collector.
Plastic Media Blasting
Plastic media blasting (PMB) is an abrasive blasting process designed to replace chemical paint-
stripping operations and conventional sand blasting. This process uses soft, angular plastic
particles as the blasting medium. PMB is performed in ventilated enclosures such as small
cabinets (a glove box), a walk-in booth, a large room, or airplane hangers. The PMB process
blasts the plastic media at a much lower pressure (less than 40 psi) than conventional blasting.
PMB is well suited for stripping paints, because the low pressure and relatively soft plastic
medium have a minimal effect on the surfaces beneath the paint.
Plastic media are manufactured in 6 types and a variety of sizes and hardness. Military
specifications (MIL-P-85891) have been developed for plastic media. The specifications provide
general information on the types and characteristics of plastic media. The plastic media types are
Type I Polyester (Thermoset)
Type II Urea formaldehyde (Thermoset)
Type III Melamine formaldehyde (Thermoset)
Type IV Phenol formaldehyde/Clear Cut (Thermoset)
Type V Acrylic (Thermoplastic)
Type VI Polyallyl diglycol carbonate (Thermoset)
Facilities typically use a single type of plastic media for all of their PMB work. The majority of
DOD PMB facilities use either Type II or Type V media. Type V media is not as hard as Type II
media and is gentler on substrates. Type V media is more commonly used on aircraft.
After blasting, the PMB media is passed through a reclamation system that consists of a cyclone
centrifuge, a dual adjustable air wash, multiple vibrating classifier screen decks, and a magnetic
separator. In addition, some manufacturers provide dense particle separators as a reclamation
system. The denser particles, such as paint chips, are separated from the reusable blast media,
and the reusable media is returned to the blast pot. Typically, media can be recycled 10 to 12
times before becoming too small to remove paint effectively. Waste material consists of blasting
media and paint chips. The waste material may be classified as a RCRA hazardous waste
because of the presence of certain metals (primarily lead and chrome from paint pigments). An
alternative solution to handling the potential hazardous waste is to recycle the media to recapture
the metals. Reusing the plastic blasting media greatly reduces the volume of spent media
generated as compared to that generated in sand blasting. When compared to chemical paint
stripping, this technology eliminates the generation of waste solvent. PMB is also cheaper and
quicker than chemical stripping. The U.S. Air Force and airlines have found PMB effective for
field stripping of aircrafts, but PMB could also be used to strip vehicles, ships, and engine parts.
As with any blasting operations, airborne dust is a safety and health concern with PMB. Proper
precautions should be taken to ensure that personnel do not inhale dust and particulate matter.
Additional protective measures should be taken when stripping lead chromate- or zinc chromate-
based paints, as these compounds may be hazardous. Inhalation of lead and zinc compounds can
irritate the respiratory tract, and other paint compounds are known to be carcinogenic. Inhalation
of paint solvents can irritate the lungs and mucous membranes. Prolonged exposure can affect
respiration and the central nervous system. Operators must wear continuous-flow airline
respirators when blasting operations are in progress in accordance with OSHA requirements.
PMB systems can range in cost from $7,000 for a small portable unit to $1,400,000 for a major
facility for aircraft stripping.
Black Beauty Abrasives
Black beauty abrasives also known as coal slag, black diamond, black blast and boiler slag is an
inexpensive media. It is one of the safer forms of abrasive media, containing less than 1% or no
silica. Black beauty media also produces little dust, however, may release hazardous air
pollutants (HAP) into the surrounding air.
Black Beauty abrasives are made from crushed liquid coal slag from utility boilers. The abrasive
contains iron (Fe), Aluminum (Al), Magnesium (Mg) and Calcium (Ca). The media comes in
sharp angular grains ranging in many sizes including coarse, medium, fine and extra fine
grained. The coarser grains can be used to remove heavy rust and provide a high degree of
profile, good for coating attachment and bonding. The finer grains can be used for cleaning
surfaces and for smoothing surfaces. The media is used on many applications including steel,
buildings, railroads and bridges. Coal slag is a fast-cutting media with a hardness of 6-7 on the
Moh’s hardness scale. The media is non-recyclable.
Copper Slag Abrasives
Copper slag abrasives are used with water jetting equipment to produce a fast cutting removal of
surface contaminants. These abrasives provide a good surface profile when used with coarser
grains. The finer grained copper slags will provide removal of lighter rust and mill scale. The
material is used applications including steel, offshore oil rigs, power plants and tanks.
Copper slag abrasive material
These abrasives are formed from the smelting process using the by-product, iron silicate. The
media comes in cubical form with sharp edges, ranging 6-7 on the Moh’s scale. Copper slag
produces low dust and contains less than .1% silica.
Sponge Blasting
Sponge blasting systems are a class of abrasive blasting that uses (1) grit-impregnated foam and
(2) nonabrasive blasting media using foam without grit. These systems incorporate various
grades of water-based urethane-foam cleaning media. Firms use the nonabrasive media grades to
clean delicate substrates. The abrasive media grades are used to remove surface contaminants,
paints, protective coatings, and rust from a variety of surfaces. In addition, the abrasive grades
can be used to roughen concrete and metallic surfaces. A variety of grit types are used in
abrasive media including aluminum oxide, steel, plastic, or garnet.
Sponge Media
The foam-cleaning medium is absorptive and can be used either dry or wet with various cleaning
agents and surfactants to capture, absorb, and remove a variety of surface contaminants such as
oils and greases. The capability of using the foam-cleaning medium in a wet form provides for
dust control without excessive dampening of the surface being cleaned. The equipment consists
of three transportable modules, which include the feed unit, the classifier unit, and the wash unit.
The feed unit is pneumatically powered for propelling the foam-cleaning medium. The unit is
portable and produced in several sizes. A hopper, mounted at the top of the unit, holds the foam
medium.
Foam-cleaning unit
The medium is fed into a metering chamber that mixes the foam-cleaning medium with
compressed airBy varying the feed-unit air pressure and type of cleaning medium used, sponge
blasting can remove a range of coatings from soot on wallpaper to high-performance protective
coatings on steel and concrete surfaces.
The classifier unit removes large debris and powdery residues from the foam medium after each
use. The used medium is collected and placed into an electrically powered sifter. The vibrating
sifter classifies the used medium with a stack of progressively finer screens. Coarse
contaminants, such as paint flakes and rust particles, are collected on the coarse screens. The
reusable foam medium is collected on the corresponding screen size. The dust and finer particles
fall through the sifter and are collected for disposal. After classifying, the reclaimed foam
medium can be reused immediately in the feed unit. The abrasive medium can be recycled
approximately six times and the nonabrasive medium can be recycled approximately 12 times.
This system removes paint, surface coatings, and surface contaminants from a variety of
surfaces. Waste streams produced from this system include: coarse contaminants, such as paint
flakes and rust particles; dust and finer particles; and the concentrated residue from the bottom of
the wash unit. Sponge blasting systems are compatible in most situations where other types of
blasting media have been used.
As with any blasting operations, airborne dust is a safety and health concern. The key advantage
to sponge blasting is the low/reduced generation of dust. Proper precautions should be taken to
ensure that inhalation of dust and particulate matter is avoided. Additional protective measures
should be taken when stripping lead chromate- or zinc chromate-based paints, as these
compounds may be hazardous. Inhalation of lead and zinc compounds can irritate the respiratory
tract, and some compounds are known to be carcinogenic. Proper personal protective equipment
should be used.
Grit Size Conversion Table
Please note that this table is for reference only. Consult your abrasive manufacturer for their
particular product specifications.
GRIT Mesh
USS* Maximum
Inches
Average Minimum Maximum
Microns
Average Minimum
8 7 0.1300 0.0870 0.0650 3300 2210 1650
10 8 0.1300 0.0730 0.0550 2286 1854 1397
12 10 0.0900 0.0630 0.0450 2286 1600 1143
14 12 0.0750 0.0530 0.0370 1905 1346 940
16 14 0.0650 0.0430 0.0310 1650 1092 787
20 16 0.0530 0.0370 0.0260 1346 940 660
24 20 0.0430 0.0270 0.0180 1092 686 487
30 25 0.0320 0.0220 0.0140 813 559 356
36 30 0.0300 0.0190 0.0120 762 483 305
46 40 0-022 0.0140 0.0095 559 356 241
54 45 0.0195 0.0120 0.0080 495 305 203
60 50 0.0160 0.0100 0.0065 406 254 165
70 60 0.0130 0.0080 0.0050 330 203 127
80 70 0.0115 0.0065 0.0040 292 165 102
90 80 0.0095 0.0057 0.0035 241 145 89
100 100 0.0080 0.0048 0.0025 203 122 63
120 120 0.0065 0.0040 0.0020 165 102 50
150 140 0.0055 0.0035 0.0015 140 89 38
180 170 0.0045 0.0030 0.0010 114 76 25
220 200 0.0040 0.0025 0.0008 102 63 20
240 200 0.0033 0.0020 0.00099 85 50 25
280 ** 0.0028 0.00154 0.00075 70 39 9
320 ** 0.0024 0.00122 0.00055 60 31 14
400 ** 0.0018 0.00087 0.00043 45 22 11
500 ** 0.0016 0.00075 0.00039 40 19 10
600 **, ^ 0.0014 0.00063 0.00035 35 16 9
700 **, ^ 0.0013 0.00055 0.00028 32 14 7
800 **, ^ 0.0012 0.00047 0.00020 30 12 5
900 **, ^ 0.0009 0.00035 0.00012 23 9 3
1000 **, ^ 0.0009 0.00028 0.00008 23 7 2
* USS - United States Standard Sieve screen size
** Abrasives finer than 240 grit cannot be accurately screened. Grading is accomplished by
hydraulic or pneumatic methods.
^ Microfine abrasives are typically only used in wet blast cabinets.
Air Basics
Compressor Selection
GUIDE TO AIR COMPRESSOR SELECTION
Customer satisfaction with a blast cabinet goes hand in hand with the air compressor and support
equipment. It is imperative that the air compressor produce enough volume of compressed air
(CFM - cubic feet per minute) to operate the blast cabinet per the manufacturers specifications.
For the customer, the most critical factor when choosing a compressor should be the volume of
air (CFM) that the air compressor generates. The volume of air will be a large factor in
determining the productivity of the blast cabinet as it relates to the corresponding blast nozzle.
The following factors should be considered when sizing a compressor:
Duty Cycle: The duty cycle is the percentage of time in ten minutes increments that the air
compressor pump should be allowed to run. For instance, if the air compressor has a duty cycle
of 50/50, and the air compressor will be running for 10 minutes, then it should run for a
combined maximum of 5 minutes ON and 5 minutes OFF. As the duty cycle increases, the pump
can run for longer periods of time without a break. Typically, rotary screw air compressors have
longer duty cycles than reciprocating air compressors. Piston air compressors are available with
100% duty cycles.
Air Volume (CFM): Blast cabinet users commonly size air compressors based on the
compressor's horsepower (HP) rating. The historical rule of thumb in the abrasive blast industry
related to air compressors states, that each compressor horsepower would produce four CFM.
Therefore, a 20 horsepower compressor should theoretically produce 80 CFM of compressed air.
However, this no longer holds true, especially with air compressors that are 10 horsepower or
less. Currently, it is not unusual for small 5 horsepower air compressors to produce less than two
CFM for every horsepower. Therefore, when shopping for an air compressor, pay more attention
to the CFM than the HP.
If a reciprocating air compressor (see definition below) will be used, it is always better to
oversize the machine than to undersize it. Determine your current requirements, take into
consideration future requirements and airline loss, and then multiply the total CFM by 1.5. This
will provide enough compressed air for a 50% duty cycle.
Air Pressure (PSI - pounds per square inch): The pressure is determined by the desired blast
pressure in the blast cabinet. It is important that the air compressor maintain air pressures higher
than required by the blast cabinet. If the blast operation requires 80 psi, then a single stage
compressor (see air compressor definitions) that operates between 95-125 psi will work,
assuming that the compressor produces enough air volume (CFM) to operate the blast cabinet.
Power Source: Oftentimes, the electrical power available to operate the air compressor is the
limiting factor. The most common electrical power outlet is rated at 115V (120V) and 20 amps.
This limits the size of the air compressor motor to about 2 HP unless, a new 208V-230V single
phase panel is added to upgrade the circuit. To keep energy costs in line, it is always
recommended to operate the air compressor on 230V-460V, three-phase power when it is
available.
TYPES OF AIR COMPRESSORS
Reciprocating Air Compressors: Sizes at 100 PSI --1/2 HP & 1 CFM to 1,250 HP & 6,300
CFM
Reciprocating air compressors are positive displacement compressors. This means, they take in
successive volumes of air, which are confined within a closed space, and elevate this air to a
higher pressure. The reciprocating air compressor accomplishes this, by using a piston within a
cylinder as the compressing and displacing element. The reciprocating air compressor uses a
number of automatic spring loaded valves in each cylinder, that open, only when the proper
differential pressure exists across the valve. Inlet valves open, when the pressure in the cylinder
is slightly below the intake pressure. Discharge valves open, when the pressure in the cylinder is
slightly above the discharge pressure.
The reciprocating air compressor is considered single acting, when the air compression, is
accomplished using only one side of the piston. A compressor using both sides of the piston is
considered double acting. A compressor is considered to be single stage when the entire
compression is accomplished with a single cylinder or a group of cylinders in parallel. Many applications involve conditions beyond the practical capability of a single compression stage.
Too great a compression ratio (absolute discharge pressure/absolute intake pressure) may cause
excessive discharge temperature or other design problems.
For practical purposes, most plant air reciprocating air compressors over 100 horsepower, are
built as multi-stage units in which two or more steps of compression are grouped in series. The
air is normally cooled between the stages to reduce the temperature and volume entering the
following stage. Reciprocating air compressors are available either as air-cooled or water-cooled,
in lubricated and non-lubricated configurations and they may be packaged to provide a wide
range of pressure and capacity selections.
Rotary Air Compressors: Sizes 30 CFM to 3000 CFM Rotary air compressors are positive displacement compressors. The most common rotary air
compressor is the single stage helical or spiral lobe oil flooded screw air compressor. These
compressors consist of two rotors within a casing where the rotors compress the air internally.
There are no valves. Because of the simple design and minimal wear parts, rotary screw, air
compressors are easy to maintain, operate and they provide great installation flexibility. Rotary
air compressors can be installed on any surface that will support the static weight.
These units are basically oil cooled (with air cooled or water cooled oil coolers) where the oil
seals the internal clearances. Since the cooling takes place right inside the compressor, the
working parts never experience extreme operating temperatures. The rotary compressor,
therefore, is a continuous duty, air-cooled or water cooled compressor package.
The two-stage oil flooded rotary screw air compressor uses pairs of rotors in a combined air end
assembly. Compression is shared between the first and second stages, flowing in series. This
increases the overall compression efficiency up to fifteen percent of the total full load kilowatt
consumption. The two-stage rotary air compressor combines the simplicity and flexibility of a
rotary screw compressor, with the energy efficiency of a two stage double acting reciprocating
air compressor. Two stage rotary screw air compressors are available in air-cooled and water-
cooled packages.
The oil free rotary screw air compressor utilizes specially designed air ends to compress air
without oil in the compression chamber, yielding true oil free air. Oil free rotary screw air
compressors, are available air-cooled and water-cooled and provide the same flexibility as oil
flooded rotaries when oil free air is required.
Rotary screw air compressors are available air cooled and water cooled, oil flooded and oil free,
single stage and two stage. There is a wide range of availability in configuration and in pressure
and capacity.
Centrifugal Air Compressors: Sizes 400 CFM to 15,000 CFM The centrifugal air compressor is a dynamic compressor, which depends on transfer of energy
from a rotating impeller to the air. The rotor accomplishes this, by changing the momentum and
pressure of the air. This momentum is converted to useful pressure by slowing the air down in a
stationary diffuser.
It is an oil free compressor by design. The oil-lubricated running gear is separated from the air by
shaft seals and atmospheric vents. It is continuous duty, with few moving parts, that is
particularly suited to high volume applications, especially where oil free air is required.
Centrifugal air compressors are water-cooled and are typically packaged to include the after
cooler and all controls.
Tank Size:
Never consider an oversized compressor storage tank size for undersized compressor CFM
volume flow rating. Your tank capacity is only as large as the volume of air stored above your
actual blasting pressure. Keep in mind how long it takes for the compressor to fill the entire tank
and remember, the only useable amount for blasting, is that amount above your actual blasting
pressure. Blasting at a reduced pressure reduces Frictional Heat created by the abrasive velocity
against the part. When the blasting pressure drops, the Frictional Heat lessons, creating increased
blasting time periods. Example...Your vehicle tire is low on air. The tire pressure measures 25
psi. You want to use the compressed air stored in your very large, big as a house, compressor
tank. The tank pressure is 20 psi, how much of the air in the tank is useable? "NONE"
COMPRESSED AIR SYSTEMS
Compressed air contains concentrated oil, water vapor, dirt and other contaminants that can
damage airlines and pneumatic components on the blast machine. Prior to using the compressed
air to operate the blast cabinet, it must be dried, filtered and regulated to the desired operating
pressure. Properly prepared compressed air prolongs equipment life, increases efficiency and
reduces blast equipment maintenance costs. This is a typically recommended set-up for a blast
operation. Some components may not be required (always consult with compressed air experts
for your specific application).
Calculating the Correct Size Blower Motor
A: CALCULATE THE TOTAL STATIC PRESSURE OF THE CABINET
INTERNAL RECLAIM - SEPARATOR
EXTERNAL CYCLONE RECLAIM
SEPARATOR
(N-200, PowerPeen)
(N-200 Cyclone, PowerStrip, HailStorm)
Air Flow Restriction
Static Pressure
(S.P.)
(in inches of
water)
Air Flow Restriction
Static Pressure
(S.P.)
(in inches of
water)
Inlet Air Filter 0.5"
Inlet Air Filter 0.5"
Reclaim - Separator 1.5" Cyclone Reclaim
Separator 3.0"
Clean Cartridge Filter 0.5" Clean Cartridge Filter 0.5"
Seasoning on
Cartridge Filter* 0.5" (3.0")
Seasoning on
Cartridge Filter* 0.5" (4.5")
Loose Dust on
Cartridge Filter** 0 - 2.0"
Loose Dust on
Cartridge Filter** 0 - 2.0"
HEPA Filtration 1" HEPA Filtration 1"
Silencer (always w/ 2
HP blower) 0.5"
Silencer (always w/ 2
HP blower) 0.5"
TOTAL CABINET
PRESSURE:
TOTAL CABINET
PRESSURE:
B: DETERMINE THE BLOWER MOTOR FEASIBILITY USING THE TOTAL STATIC
PRESSURE CALCULATION
If the total static pressure calculation with a specific size blower motor falls within the green or
yellow bands, then
the motor and blower impeller will provide sufficient air volume delivery. If a cabinet's total
static pressure falls to the far right side of the yellow band, the client may want to consider
upgrading to a larger blower motor and impeller.
* Seasoning on the cartridge filter refers to the dust that imbeds in the cartridge, but will not detach
when the filter is cleaned.
** Static pressure may vary depending on the extent of filter contamination and when the last time the
cartridge filter was cleaned. MBA recommends using 2.0" s.p. in the calculation.
*** 1/2 HP motor installed on standard collector. 3/4 HP motor installed standard on expanded
collector.
Dictionary of Terms
100% Welded: Often times, less expensive blast machines are manufactured using light gauge
steel with spot welded cabinet construction that can lead to shorter cabinet life and abrasive
leakage when the machine is being used. Every machine in the Media Blast product line,
including, all of our light duty models, are 100% welded utilizing 12 and 14 gauge steel for the
construction of the machines. This gives you a more durable machine construction and prevents
cabinet leakage during machine operation.
Abrasive Gun Oscillators: The feasible number of guns used in one cabinet is determined by the abrasive type and the part shape. Too many guns will create very high machine maintenance and
operating cost. Gun oscillators are used to cover a wide area but, keep in mind, gun overlap is
required, and this overlap reduces conveyor speed. Many different types of oscillators are used
with special machines.
Abrasive Hopper Tuner Valve: All machines that include the pneumatic conveyor include an
outside abrasive storage hopper. Because the pneumatic conveyor must handle all the abrasive
each time it exits the blast nozzle, it must be nearly 100% efficient. This can often retain dust
that can affect cabinet visibility. The tuner valve is set by the customer to eliminate unwanted
fine dust during abrasive conveyor operation. Elimination of the finer dust will help with cabinet
visibility.
Abrasive Mixing Valve: The abrasive mixing valve is used to meter and control the amount of
abrasive entering the abrasive delivery hose. A properly adjusted abrasive mixing valve helps to
eliminate all abrasive delivery surges and it also allows for re-adjustment of flow when changing
abrasive sizes. Blasting machines are not capable of the fine adjustment required, for the wide
variety of abrasive sizes available in the industry today unless, they have a quality mixing valve.
Abrasive Separator: See Separator Reclaimer
Ambient Air Dryer: Moisture in the compressed air supply causes abrasive flow problems and
dust collector filter problems. MBA's unique inline ambient air dryer requires no floor space and
mounts directly onto the blast cabinet.
Bar Grating: Grating material is used in large abrasive blasting cabinets because of its strength when spanning great distances without additional support. It is also used when high wear
abrasive applications exist.
Barrel Reclaim Separator: This option is available with the pneumatic abrasive conveyor in lieu of the high efficiency cyclone separator reclaimer that is used with the finer abrasives. It is used
for applications that require conveying the abrasive outside the blast cabinet when the abrasive
size is large, 60-120 mesh. This option will increase the life of the separator when used with
larger cutting abrasives.
Batch Loads: Is a term used to describe small parts processing without operator contact. Batch loads are processed using a rotating basket or barrel assembly. As the barrel or basket spins,
random part mixing takes place inside the barrel or basket, this, coupled with a fixed gun
directional blast pattern, processes parts in a given time period without the need for a machine
operator.
Belt Conveyors: Parts can be passed through cabinets using many different belt types, link belts and flat belts being the most common. Multiple gun stations are used, both fixed and oscillating,
to cover the part moving on the belt assembly.
Blow-Down Controls: The Blow-Down Controls option allows for the quick depressurization of
the blasting pressure pot, which permits faster pot re-fill. The smaller the blasting pot, the more
beneficial the blow-down controls are.
Blow-Off Gun Assembly: All production cabinets manufactured by Media Blast include the
inside cabinet blow-off gun assembly. This feature is also available as an option on the Light
Duty and General Purpose blasting cabinets.
Boron Carbide: Is a high wear material that is used for blast nozzles when a cutting abrasive is
used. Boron Carbide is about double the cost of the less expensive tungsten carbide but, it will
last 4-6 times longer in use.
Cartridge Filter: Unlike other filtering materials used for dust collector, 'cloth', the filter cartridge has a certified nearly HEPA quality to it. Cloth filters consist of woven materials that stretch
during the cleaning process resulting in reduced filter efficiency. Filter cartridges also yield
greater filter collection surface in a smaller required filter area. When purchasing a machine,
filter replacement time and cost, is greatly reduced when using cartridge style filters.
Certified HEPA After Filtration Packages: HEPA After Filtration is not always used for hazardous dust. This option can be used for Cell machines, Small Room machine operation or
Ultra-Fine abrasive applications to control legal grains per cubic meter on dry abrasive blasting
equipment. Also offered for applications dealing with hazardous dust conditions.
Clearview Window: Oversized operator's view window.
Contained Dust Discharge Assembly: MBA expands upon its popular hopper style dust collector by offering a contained dust discharge assembly (standard with HEPA filtration). This assembly
incorporates a slide gate on the bottom of the dust collector hopper. When the slide gate is
opened, the dust is released through a duct and into a dust collection vessel. When the dust
collection vessel is lined with a bag, the vessel top can be removed and the contents disposed of
without the operator ever being exposed to the dust. This option is highly recommended for
operations blasting with hazardous abrasives or blasting on materials that may release hazardous
material dust. Slide gates and taller hopper heights are available to accommodate drum waste
disposal. Dust collection systems are also available to accommodate the use of a full size steel
drum.
Cutting Abrasive Package: This should be included on machines operating with high wear or cutting abrasives. The package consists of a window protector, boron carbide nozzle, white
polyethylene cabinet wear plates, heavy-duty bar style work grates and a steel hopper wear plate.
Certain MBA machine models include some of these items as standard features.
Cyclone: Is a pneumatic centrifuge used to separate and retain abrasive sizes that are 150 mesh and smaller. Cyclone Separators also introduce air into the abrasive which helps to keep the
abrasive dry. This creates a more uniform delivery of the finer size abrasives.
Direct Pressure: Direct Pressure machines use a pressure vessel to pneumatically push the blast media through a single abrasive hose and out the blast nozzle. Direct Pressure machines can be
used with heavy abrasives like steel shot or steel grit, in addition to most other common abrasive
types and sizes.
Directional Blasting: Is a term used to describe abrasive blast machinery equipped with handheld
or fixture mounted blast guns. This allows for specific part areas to be processed and prevents
the blasting of areas on the part that you do not want processed. Operation of the blasting is
accomplished by using compressed air to convey the abrasive media through the gun or guns to
the part surface.
Double Skinned, No Spill Door with Heavy Duty Appliance Style Latch: MBA uses a heavy duty latch mounted to a double wall, 14 gauge steel door. Our doors will not warp or flex and our
cabinets do not leak abrasive when the doors are opened.
Downdraft: Is a term used to describe the direction and speed of air flow. Downdraft is
frequently used to describe the speed of air, just above the work surface, of a pollution control
workbench.
Enclosed Top: All Tornado models are available with an optional Enclosed Top Assembly
upgrade, which is used to help confine dust particles with increased dust particle velocity. This
top assembly includes the back, sides, top and movable operator view panel. The standard panel
is constructed using a hinged Plexiglas panel and an operator open work port area is located
below the operator sight panel. This panel is also available in optional safety-glass construction
to eliminate possible scratching. The Enclosed Top is used to confine dust particles being
accelerated during sanding, de-burring and many other operations.
Ergonomic Sit Down System: This option is available as a bolt-on padded shelf style armrest that attaches to the complete line of Micro Blast Machines. It is also available as a system that can be
incorporated into a complete custom blast cabinet. This custom option includes a different
window slope that has been lowered to improve visibility into the blast cabinet from the sit down
position. The blast cabinet hopper has been redesigned so that the operator can sit comfortably
while blasting. An adjustable armrest and shrouded foot pedal completes the package.
Ergonomically Constructed Cabinets: Ergo can be more than just sitting down. Cleaning the dust collector, setting the controls and movable foot controls are also part of properly designed
cabinets. Ask Media Blast about all the features that create a True Ergo machine.
Exhaust Blower: In Blasting Cabinets:
The machine exhaust blower is used to create cabinet visibility. It is a necessary
component for the efficient operation of abrasive separator reclaimers. Separator
reclaimers remove unwanted dust and spent abrasive from inside the cabinet. To
establish the number of cabinet air changes per minute made possible by the exhaust
blower, take the cabinet blast chamber area in cubic feet and divide it into
the exhaust blower CFM rating. Exclude the machine hopper size when calculating
the cabinet volume.
In Tornado Pollution Control Benches:
Important to any down-draft work bench, is the type of blower being used. The
exhaust blower creates the down-draft air-flow used to capture the dust and
contamination and the blower construction type, determines the suction rating
measured in Static Pressure, a measurement of inches of water lift. A
critical balance is needed between suction and air volume, and Media Blast
manufactures all of its blowers based on these two very important factors.
Exhaust Silencer: The Exhaust Silencer is used to reduce the noise level that is created by all Class III dust collector exhaust blowers. Larger blowers are used to create better cabinet
visibility but, they also create noise levels that are unacceptable for continuous machine
operation.
Expanded Cabinet Heights: MBA offers two cabinet heights on the most popular cabinet sizes (3636, 4836). Our standard height production blast cabinet has a 30" working height and a view
window angle of 45°. This allows for the ergonomic blasting of smaller parts without having to
put your nose against the view window while working. Our expanded height cabinet offers 36"
of working height with a view window angle of 17°. This window angle is more efficient for
taller parts that won't fit in the standard height cabinet. If the normal cabinet heights will not
suffice, MBA offers extended heights as optional choices.
Expanded Two Cartridge Dust Collector Upgrade: This option provides more filter surface area (440 sq. ft.) when dusty abrasives are used or when the cabinet usage is three + hours per day.
Filter Cycle Cleaning Gauge: This feature is standard on all MBA production cabinets. This option is not offered at all on other manufacturers cabinets. Clean filters are an important part of
the maintenance process. Neglect, will result in significant repair costs and lower productivity
(due to poor visibility), so it is critical to know when to change the filters. The MBA filter cycle
cleaning gauge helps to remind the operator when critical maintenance is due.
Fine or Ultra Fine Abrasive: Any material pneumatically propelled through a blast nozzle is
commonly known as abrasive or blasting media. Fine and Ultra Fine abrasives measure 150-325
mesh in abrasive particle size.
Fixed Turntable: Heavy or awkward parts can be moved much easier inside a blast cabinet when it is equipped with a turntable. The turntable can increase productivity significantly. Choose
from manual or powered turntable models available in many sizes (up to 48" diameter) with a
standard weight capacity of 300 pounds (heavier capacities are available). The frame to hold the
turntable is mounted inside the machine and the turntable top rides and rotates 360 degrees on a
series of double sealed bearings. All MBA turntables are slotted to allow for the use of part
holding fixtures and they are equipped to lock in position if desired.
For turntables that exit the cabinet for loading and unloading see "Mobile Work Carts and
Tracks".
Foot Operated Blast Valve: A foot operated blast control, gives the machine operator maximum mobility inside the blast cabinet, by controlling the blast cycle, using an on-off foot operated
pedal. This is important when operating inside smaller cabinet sizes. This also creates a smaller,
more compact, easy to use blast gun size. Trigger controlled guns are large and troublesome to
operate when installed inside a blast cabinet.
Frictional Heat: Dry abrasive blasting generates surface heat on the part that is being processed. This frictional heat, can damage thin parts or parts made of certain materials such as plastics or
composites. Frictional heat increases when the compressed air being used is increased and this is
the single most important factor in reducing part-processing time when using larger gun sizes.
General Purpose: A term used to describe a "hybrid" mix of light duty and production
machinery. The cabinet is large but, the dust collector capacity is limited. General Purpose or
non-production machines are ideal for infrequent use on larger parts.
Glass Window Protector: Commonly called "Window Protectors", these are used to protect the
operator view window during machine operation when using cutting abrasives. Cutting abrasives
can cause window etch. MBA uses a secondary piece of glass to protect the main safety glass
view window from being etched. The protector glass is replaceable and provides a durable,
inexpensive, way to protect the view window during machine operation. Using softer materials
like plastic sheets is not advised, due to the soft nature of the protector and its ability to create
static electricity, which will draw the abrasive inside the cabinet to the view window, creating
limited visibility.
Gun/Blast Nozzle Holding Fixture: This feature, allows the operator, to hold and maneuver the part to be blasted with both hands because, the blast nozzle is fixed in position. This option is
recommended for operations that blast small or difficult to hold parts.
Hazardous Duty Dust Collectors: Media Blast manufactures the Haz-Mat HEPA filtration package for reduced maintenance contact with collected dust. The standard dust collector
requires that the operator come in contact with Primary Filters during filter replacement.
To minimize exposure to the collected dust that is generated in applications that may include
hazardous materials, MBA has developed a hazardous materials dust collector. This dust
collector package helps reduce operator contact with the primary filters during filter replacement.
HEPA After-Filtration, Automatic Reverse Pulse Filter Cleaning and a direct reading monitoring
system are included with this optional upgrade package making it right for collection of
hazardous dust materials.
HD Kit: This model can be purchased without the HD Kit, the kit can be purchased and added at
a later date. The Space Saver HD includes this HD Kit which produces 30 air changes per minute
by using a separator reclaimer that removes the dust and dirt from the abrasive. If you are
looking for 100% welded machine that you can operate using any Shop Vacuum, purchase the
Space Saver HD without the HD Kit (the machine will include a smaller 12 CFM gun assembly
to allow for operation with any Shop Vacuum Dust Collector).
HEPA Filter: HEPA is an acronym for High Efficiency Particulate Air Filter, which was used in U.S. military specifications beginning around World War II.
In Blast Cabinets:
This filter should be installed when hazardous materials are being blasted (e.g. chromium,
cadmium, nickel, zinc, lead, asbestos, or radioactive materials).
In Tornado Pollution Control Benches:
The Tornado is a pollution control bench, used for collecting nuisance dust. The optional HEPA
after-filter can be added, when better filtering ability is required for small room applications
when greater dust capture is required. HEPA filters are not cleanable but, all Tornado units also
include the standard primary filters that protect the HEPA filter during operation for better
longevity.
High Velocity Part Vestibules: Passing a part through a blasting cabinet requires passing the part through a high-velocity vestibule with vestibule length to retain the abrasive inside the cabinet.
This vestibule length with the cfm created by the dust collector blower is used to reverse abrasive
direction and prevent abrasive escape. Unless this is calculated correctly the machine will not
function properly.
High Wear Cabinet Kits: With any cutting abrasive some features are required to prevent excessive machine maintenance. Window Protectors, HD Bar Grating, Boron Nozzles and Liners
are all items that greatly reduce operation costs. This can also lesson maintenance on non-cutting
abrasives but, often are not included as standard.
Hopper Bottom Dust Collector: When looking for machinery, always look for a hopper bottom style dust collector for ease of cleaning. All Production style machines manufactured by Media
Blast are equipped with dust collector dust storage hoppers. This allows for the removal of
collected dust, into plastic storage bags, which prevents dust escape during machine service.
Hopper-Less Machine Construction: Media Blast offers air-swept floor sections to eliminate the height of standard machine construction using a hopper assembly. The width and depth of any
cabinet with the angle of repose for the abrasive designs the hopper slope. Most operator work
levels are 36-inches and higher. Hopper-Less construction lowers the work level to 18-inches.
This can be useful for tall parts or parts passing through using an overhead hoist.
Integrated Vacuum Cleanup Assembly: MBA is the only manufacturer in the industry that offers this unique option. We convert the dust collector into a shop vacuum that can be used for
cleaning up the work area around the cabinet and cleaning the abrasive out of the blast cabinet.
This option requires a minimum of the dual cartridge dust collector and the 1,160 CFM exhaust
blower.
Laminated Safety Glass: Two separate pieces of glass bonded together with a plastic sheet to
prevent glass shards if the glass is broken.
Light Duty Blaster: Light duty, describes machinery used on a non-daily basis. One feature
missing from light duty machinery is the production style dust collector with the large filter
surface area. Light duty machines are the least costly to purchase and usually have cabinets
measuring 24 inches by 24, 30 or 36 inches. These cabinets are generally manufactured using
spot welded construction however, all Media Blast machines, are manufactured using 100%
welded construction. Most light duty machines operate with no more than 20 CFM of
compressed air.
Long Wear Abrasive Hose: A hose material used when high wear cutting abrasives are being
used. This type of hose eliminates the frictional wear created on normal abrasive hoses.
Magnahelic Gauge: The magnahelic gauge monitors the condition of the dust collector filters (or HEPA filters) by monitoring the differential pressure between the clean and dirty side of the
filter. The magnahelic gauge is available with or without set point indicators and indicator lights.
When the filters become dirty, indicating the factory preset differential pressure has been
reached, the set point indicator triggers a red light alerting you, that it's time to change the filters.
Magnetic Separator: This is used to remove metal contaminants that may be present during
operation when using plastic abrasive.
Maintenance Meter or Hour Meter: This feature will simplify the maintenance on your new MBA blast cabinet by tracking the amount of time the machine is in operation. By using the non-
resettable hour meter, you can create a logbook that indicates basic machine maintenance
schedules, including abrasive change out.
Manual Reverse Pulse: This component is used to reverse the airflow direction inside the
machines dust collector. This creates a quick pulse of air down the center of the dust collector
cartridge which forces the collected dust off of the filter surface.
Micron: Unit of measurement, 25 microns equals .0012 or 1/25,000 of an inch.
Mirror Cabinets: Used to create the perfect fit with the smallest machine footprint. Any Media Blast units can be supplied in a mirror layout. Often used for left hand operation but, more often
used to create a better shop layout and more efficient operation. Mirror machines include mirror
service doors on the dust collector and often mirror blower rotation.
Mobile Work Cart and Track: For large, heavy and awkward objects that need to be blasted, the mobile work cart and track allow the objects to be easily loaded and unloaded from the cabinet.
This eliminates the need for potentially dangerous clam-shell style cabinets. All mobile work
carts are equipped standard with internal cabinet track and locking turntables with a 300 pound
weight capacity. Various lengths of external track extensions and powered operation are also an
available option.
MSDS: A material safety data sheet (MSDS) is a form containing data regarding the properties
of a particular substance. An important component of product stewardship and workplace safety,
it is intended to provide workers and emergency personnel with procedures for handling or
working with that substance in a safe manner, and includes information such as physical data
(melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity,
storage, disposal, protective equipment, and spill-handling procedures. MSDS formats can vary
from source to source within a country depending on national requirements.
Multiple Gun Applications: Multiple guns for siphon or multiple nozzles for pressure, with and without additional operator stations are available on most Production type equipment
manufactured by Media Blast. Adding a Tumble Barrel to a standard cabinet also adds one more
gun assembly with controls. This special feature has almost limitless possibilities.
i. Fixed
ii. Oscillator Mounted
iii. Siphon or Direct Pressure
Multiple Work Stations: A 48" part inside a 48" cabinet will not move from side to side. Often part movement is required to process the ends of the part. With larger cabinets multiple operator
work stations are often required for part coverage. Media Blast also offers a 90-degree operator
work station on the machine side or side access door, this permits part processing from another
direction without part removal and flipping of rotation.
Nuisance Dust: OSHA Definition: Fibrogenic dust, such as free crystalline silica (FCS) or
asbestos, is biologically toxic and, if retained in the lungs, can form scar tissue and impair the
lungs ability to function properly.
Nuisance dust, or inert dust, can be defined as dust that contains less than 1% quartz. Because of
its low content of silicates, nuisance dust has a long history of having little adverse effect on the
lungs. Any reaction that may occur from nuisance dust is potentially reversible. However,
excessive concentrations of nuisance dust in the workplace may reduce visibility (e.g., iron
oxide), may cause unpleasant deposits in eyes, ears, and nasal passages (e.g., portland cement
dust), and may cause injury to the skin or mucous membranes by chemical or mechanical action.
Open Top: All Tornado models include the Standard Top Assembly used to produce downward
directional air-flow away from the operator location at the front of the unit. This top assembly
includes the back and side wing pans used to create directional down-flow above the operator
work grate surface increasing dust capture.
Pinch Roller Conveyor: Vertically mounted roller pairs used to push, pull or push-pull parts into and through a cabinet for processing. Horizontal pairs are used to rotate parts during processing.
PLC Machine Controls: Often used to increase production on parts moved into and out of or through the cabinet using various types of part movement or part conveyors.
Pneumatic Conveyor: A pneumatic conveyor is a device used to convey abrasive pneumatically during operation of the blast cabinet. Ducting is one of the more common products used for
conveying abrasive.
The pneumatic conveyer works in conjunction with the cyclone separator for separation of fine
and ultra-fine abrasive. Also used in operations with larger cabinets or multiple cabinets that
requires standard operator heights.
Polyester Filter: This is a washable filter cartridge often used for applications that require faster
cartridge cleaning.
Powered Mobile Work Carts: Mobile Work Carts roll into and out of the cabinet. All Media Blast Mobile Work Carts include a turntable assembly. This turntable can also be powered using
a constant or variable speed gear-motor assembly.
Powered Roll-Up Doors: Vertical Doors can often save valuable floor space. Media Blast does not use counter-balanced or cylinder operated systems. Manufactured as a complete assembly in
a steel housing mounted to the top of the cabinet. This option can be manually operated or
equipped with a powered gear motor assembly.
Powered Turntables: Fixed Turntables located inside the cabinet are often powered allowing the operator to jog parts within reach for part processing. Powered Turntables can also be used with
a fixtured abrasive gun for part processing or it can be manual or time-cycle operated with
constant or variable speed.
Pressure Blower: Four basic blower types exist. The lower the blower class, the greater the
blower CFM air movement but this also lowers the blowers ability to create suction.
Tornado Pollution Control Benches:
Media Blast manufactures a Class III blower for all Tornado models creating a high blower CFM
air movement at greater static pressure ratings. This moves air longer through filters that are dust
laden. Air quantity and length of air movement are balanced using this Class III blower type.
Pressure Pot: These are used with direct pressure blast machines to pneumatically push the abrasive through the blast nozzle. Pressure pots produce a faster abrasive velocity, the most
concentrated abrasive patterns and they can operate using the heaviest of abrasives i.e. steel grit
and steel shot.
Production: Production blasting machinery is machinery that is used on a daily basis. The
defining factor in production machinery is the dust collector. Production machines require large
amounts of dust collector filter surface area. The larger the dust collector filter surface area is,
the greater it's capacity for storing collected dust and maintaining cabinet visibility during
operation. Dust collectors with dust storage hoppers are easier to clean and therefore cleaner to
operate. Production cabinets are typically made using heavier gauge steel with 100% welded
construction. They also have the greatest variation of cabinet sizing.
QwikStrip Nozzle: A longer than normal nozzle that is used to maintain high abrasive impact
velocity and dense abrasive particle concentration. Because of the extended length of these
nozzles, they can be used on direct pressure machines only.
Raised Operator Platform: This is a platform used to raise the operator height, which allows for placement of the pressure pot, below the machine hopper. By doing this, you produce a better
machine hopper slope, for feeding the pot. This eliminates the need for a pneumatic conveyor on
a larger cabinet, which substantially increases the operating cost of the machine.
Random Part Mix: This describes the part mixing that takes place during the tumble blast
process. By increasing the random part mix speed, you increase the tumble cycle time, which
results in greater machine production output.
Replaceable Hopper: MBA has the only truly modular blast cabinet. If the hopper wears out after
many years of use, it can simply be replaced because, it is not welded to the cabinet. If your
blasting requirements change, MBA's production blast cabinets, can be converted from one style
to another, simply by changing the hopper or adding additional accessories. For example, a
production siphon cyclone cabinet can easily be converted to a pressure cyclone, a siphon or a
pressure blast cabinet. While many manufacturers can convert between siphon cyclone and
pressure cyclone, no other manufacturer can measure up to MBA's flexibility. MBA is the only
manufacturer that offers an optional system, which allows the user, to automatically dispose of
the abrasive after one cycle or operate the system as a normal abrasive blast system, which
automatically recycles the abrasive.
Reverse Pulse Dust Collectors: A device used to clean the dust collector filter surface by using a pulse of compressed air. This type of setup is recommended for use with two or more filter
cartridges and where high humidity conditions exist. It can be automatic or manual pulse.
Roll Up Side Access Doors: In years past, some side access doors were vertical lift doors. Today's technology allows for construction of the side access door as a contained roll-up door
assembly. This makes possible, the addition of a powered gear motor assembly and a rubber
inside door lining. Closing the door inside the machine hopper is an advantage when using this
type of access door.
Roller Conveyors: Simple roller conveyor sections or power connected rollers can be used to
move flat parts or other parts using totes. Roller conveyors are restricted by the length and shape
of the part.
Roller Conveyors: Simple paired roller sections or power connected rollers can be used to rotate single parts inside the cabinet or move flat parts through any cabinet using part totes. Roller
conveyor layouts can be restricted by the minimum length and shape of the part.
Rubber Dipped Baskets and Barrels: Tumble Basket and Barrel machines require the parts to be rotated inside the barrel assembly. The parts provide the required protection for the baskets and
barrels during the blasting process. Often times, the steel basket or barrel requires rubber dipping
to prevent the parts from being damaged when the parts rub against the steel barrel surface
during the tumbling process.
Safety Door Interlocks: Standard on all production blast cabinets and optional on all light duty
cabinet models. A safety door interlock, shuts off the air to the blast nozzle, when the door is
open or if the door is opened while blasting is in progress.
Safety Plate View Window: Glass view windows perform best because, unlike Plexiglas or
plastic which attracts abrasive dust via static electricity, glass is a more durable static free
material. Safety plate glass is one of the safest materials because, unlike tempered glass, safety
glass is comprised of two pieces of glass bonded together with a single clear plastic sheet
between them.
Satellite Part Rotation: A Part Rotation Fixture used to spin the part in conjunction with fixed or oscillating abrasive guns. It can be stationary or attached to the powered turntable assemblies.
Scrubber: Wet type scrubbers are used for many applications for the collection and cleaning of
both gas and solid dust particles. Any possible explosive dust will require wet scrubber
collection to eliminate the fire hazard. Most are made using stainless steel construction with
water and air-flow used for the collection of the dust.
Separator Reclaimer: The Separator Reclaimer or Abrasive Separator Reclaimer prevents the
loss of usable abrasive when the exhaust blower exchanges inside air for outside cabinet air
creating the negative cabinet air pressure. Abrasive separator reclaimers are pneumatic
centrifuges capable of separating usable abrasive from dust and unwanted, worn abrasive. This
device makes it possible for usable abrasive to circulate over and over inside the abrasive cabinet
while removing unwanted dust which is a spent abrasive. Abrasive separator reclaimers are
available in different efficiency ranges, which should be matched to the abrasive size in use.
Some separators operate with media sizes of 0-150 mesh and others are intended for finer sizes
of 180-400 mesh. In addition, separator reclaimers are available in different CFM ratings, with
larger separators for larger exhaust blowers.
Shrouded Foot Pedal Assembly: An OSHA approved shrouded foot pedal assembly is available as an option to MBA's standard foot treadle. To accommodate the shrouded foot pedal assembly,
the front leg brace is moved back 8" from the front of the cabinet.
Sight Window: Unlike the operator view window, the sight window is used to allow outside light
to enter inside the cabinet. A Sight Window is often installed on the top of wet blasting machines
to allow the light from the outside light fixtures to enter the cabinet.
Single Power Source: Machines with fractional motors operate from a 120-volt power source. Machines with increased motor horse power, 1 HP and larger are available with an electrical
box, a transformer for low-voltage operator control, magnetic starter, heater and low-voltage fuse
protection. This option, gives the customer the opportunity to choose the supply voltage and
phase required for the application.
Siphon Blast: A term used to describe the type of abrasive delivery system used on an abrasive
blasting cabinet. A siphon machine uses an injection gun to create suction on the abrasive supply
hose. The abrasive hose then conveys the abrasive, using suction or siphon, to the gun where the
compressed air hose is used to accelerate the abrasive. All siphon type machines include two
hoses on the abrasive blast gun assembly. Siphon machines are the most common type of blast
machine. All siphon gun assemblies include an air jet that is used to create the siphoning effect
and also regulate the amount of compressed air required to operate the machine.
Soda: Soda or baking soda is a blast abrasive used for one shot applications where you dispose of
the abrasive as soon as it comes off the parts that are being blasted. By doing this, you minimize
contamination of the abrasive that could be transferred to the part. Soda is also used to prevent
part damage on sensitive materials during the cleaning process.
Soda Delivery System: Optional Direct Pressure system used to deliver soda in the Blizzard model blast cabinet.
Special Blower Combinations: System Static Pressure can affects blower CFM. The amount of CFM introduced by the blasting nozzle(s) can require larger blower assemblies. Blowers are
sized to the system static and machine requirements for operator visibility. This can often change
the pneumatic conveyor by adding or changing the size.
Special Cabinet Layouts: Almost any customer required special cabinet layout can be supplied by Media Blast before the machine is fabricated. This is often required with many Oversized
Parts, Special Operator Station Layouts, Part Entrance and Exit Vestibules, Taller, Wider,
Deeper cabinets and many other simple modifications requiring cabinet modification before
manufacturing.
Special Dust Collector Requirements: Media Blast offers Dust Collector Upgrades the include; HEPA After-Filtration, 2, 4 and 6 Filter Upgrades for 440, 880 and 1320 Sq.Ft. filter areas for
high daily production and special blower configurations for high static and other increased
blower cfm ratings required for additional dust collector options.
Special Electrical: Media Blast offers a full line of equipment operating on 120 volt, single phase power source. Some machines include High Voltage Single Power Source Electrical as standard.
The customer can indicate any Voltage, Phase and Cycle to create a specific machine electrical
package. All 120 volt models can be upgraded to High Voltage Single Power Source as an
option.
Special Pneumatic Abrasive Conveyors: Siphon and Direct Pressure machines equipped with additional guns and or nozzles can often require larger abrasive storage hoppers and larger
pressure pot assemblies. Media Blast offers non-standard pneumatic conveyors sized for non-
standard blower cfm ratings and non-standard pressure pot sizes.
Stainless Steel Dry Cabinets: Media Blast is one of a limited number of manufactures offering stainless steel Wet Blasting Equipment. This allows Media Blast to also offer stainless steel dry
cabinets required to lesson or eliminate carbon steel contamination during part processing. All
cabinet items coming in contact with the abrasive are fabricated from stainless steel, including
pneumatic conveyors and separator reclaimers. Some limited items, mixing valves etc., can be
stainless construction by offered in standard mild steel construction standard.
Static Electricity Grounding Kit: Static electricity is generated when two dissimilar materials are
rubbed together. This is a condition that can worsen with climate change. The static grounding
kit prevents the cabinet from acting as a condenser, when the abrasive comes in contact with the
steel cabinet walls, by preventing the static charge build up inside the cabinet.
Static Pressure: Static Pressure can have many separate definitions determined by each
application.
Tornado Pollution Control Benches:
With respect to the Tornado Pollution Control Work Benches, Static Pressure can be explained
by saying the resistance of air to flow measure in Inches of Water. The higher the static pressure
rating, the greater the suction ability of any blower or the ability to move air when resistance to
air-flow is offered. This resistance is often called pressure differential, which takes the form of
dust build-up on collection filters, creating a need for greater suction or static pressure ratings.
Steel Bar Grates: Media Blast uses two types of bar grate material, steel bar grating and
fiberglass bar grating. Steel has a greater weight bearing capacity and fiberglass helps protect the
parts from being scratched as they are being worked on.
Table Top Velocity: The down-draft velocity, movement of air in feet per minute, is greatest at
the part work surface. Blower CFM divided by work surface area measured in sq. ft. equals table
top velocity described in feet per minute velocity.
Timed Window Wash: This is a clear water rinsing assembly inside the cabinet that is timed, to
provide a momentary pulse jet stream of clean water against the operator view window. All
water used in this process is removed from the cabinet to prevent reduced slurry concentrations.
The water that's removed from the cabinet can be used for cabinet make-up water.
Toe Kick: An open area at the bottom of a bench or cabinet, for the placement of the operator's
feet, which allows the operator to stand against the bench or cabinet while working. Commonly
used in kitchen cabinet construction.
Track Extensions: See Mobile Work Cart and Track
Tumble Barrel: While most applications today using blast cabinets require manual operator directional blasting, some parts, because of their size and run quantity can be blasted in batch
loads using a machine equipped with a rotation device known as a tumble barrel. The term
Tumble Barrel, describes a horizontally mounted barrel with the rotation axis horizontal. Tumble
barrel machines can process small parts up to 5 inches in length. Tumble barrel machines
basically unload themselves because of the horizontal rotation axis of the barrel. This permits jog
rotation of the barrel which brings the barrel door to the bottom, which allows the parts to drop
into a container when the door is opened.
Tumble basket machines have an open top basket mounted with the rotation axis at 45 degrees
from horizontal. These machines are used for the processing of smaller longer parts up to 7
inches. Because the tumble basket is mounted inside the machine hopper, the parts must be
unloaded from the basket by hand after being processed.
Tumble Basket: See Tumble Barrel
Vacuum Blower: Vacuum Blowers are considered a Class four blower, used to flow limited air
volumes at high suction ratings. They are used for high air suction velocities and limited air flow
in small air ducts and or hoses. Not good for dust capture and collection because of the low air-
flow amounts.
Wet Blaster: While most applications today require dry blasting, some remain that are truly jobs
for wet blasting machinery. The frictional heat generated by dry machines can damage or destroy
certain parts. Using a wet blasting cabinet can eliminate the frictional heat generated during part
processing. Another plus with wet machinery is the ability to produce a chemically clean part
surface with minimal surface removal. Using 4000 to 5000 mesh abrasive is not an option when
using a dry blasting machine but, this abrasive size can be used when using a wet blasting
cabinet like the Media Blast Hurricane model.
Window Molding Tool Kit: Media Blast uses a positive sealing window molding to produce a
100% sealed view window installation. Using the window molding tool kit allows for easy
installation of the operator view window if replacement is ever required.
Window Protector Assembly: More commonly called "Window Protectors", these are used to protect the operator view window during machine operation when using cutting abrasives.
Cutting abrasives are capable of creating window etch and using a sealed secondary window
assembly located inside the machine will protect the more costly safety glass view window from
being etched. Using softer materials like plastic sheets is not advisable due to the soft nature of
this style protector and its ability to create static electricity, which will draw the abrasive to the
view window creating limited visibility.