Arc Welding Equipment

6831.26

Welding Machines• AC – (alternating current)

used for most agricultural arc welding jobs and has low purchase cost compared to other arc welders

Welding Machines• DC (direct current) are

generator operated and can be used where regular electrical power is not available

Welding Machines• AC/DC – welders use a

rectifier to change regular AC current to DC

• These welders can be used as either AC or DC

Welding Machines• TIG (tungsten inert gas) welders

have an electric power unit, a pressure reducing regulator, electrode holder, tungsten electrode, nozzle, cables and hoses, and a gas supply unit

TIG•The two gases used are helium and argon

TIG•The tungsten electrode is not consumed (burned) and there is no slag on the bead

TIG• TIG is good for welding

stainless steel and aluminum because it is stronger and more free of corrosion than other welders

Welding Machines• MIG (metallic inert gas)

welders are wire feed welders that use a consumable wire fed automatically through the torch and can be used in industries as an automatic welder

Welding Equipment• Helmet, leather gloves,

leather aprons, leather welding jacket, and leather boots are for protection

Welding Equipment•Chipping hammer removes slag, and wire brush removes rust and dirt

Welding Equipment•Clamps and vise grip clamps are used to hold metal in place for welding

Electrodes•Electrodes are wire cores or rods usually covered in flux

Electrodes•Size is the diameter of the metal rod not including flux

Electrodes•Classification code system has a letter and four numbers such as E6011 or E6013

Electrodes• E6011 is the most commonly

used electrode for welding farm projects because it can be used for all purpose welding of mild steel, has deep penetration, and can be used with both AC and DC welders

Electrodes•E6013 is a good general purpose electrode but only has medium penetration

Arc Welder• An electric arc welder is used

to weld two pieces of metal by melting and joining the edges of each using an electrode to help fill the space between them

TIG Welder•TIG welders are best for welding aluminum and stainless steel

MIG Welder •MIG welders are the best welder for welding very thin metals

Shade 10• A shade 10 lens in a

welding helmet protects the eyes of the person welding or the person watching someone weld

Chipping Hammer•A chipping hammer is used to remove the slag (crust) off a welded bead

Basic Arc Welding Procedure

6831.27

Clean Metal•Metal should be cleaned before it is welded

Clean Metal• A grinder is the fastest

way, but a wire brush or other methods may be used to remove paint, rust, dirt, or oil

Beveled• Metal more than ¼” should

be beveled at a 30 degree angle and placed 1/16” to 1/8” apart before two pieces are welded together

Welding Joints• Butt – two pieces of metal

lying in the same plane such as end-to- end or edge-to-edge in a flat position

Welding Joints•T – two pieces of metal placed together to form a T (two pieces at a 90 degree angle)

Welding Joints•A fillet weld is used to fuse the two pieces permanently

Lap•Two pieces of metal overlap each other

Corner•Two pieces of metal make a 90 degree corner

Edge•Two pieces placed parallel to one another or stacked on top of each other

Amperage Setting• Welding position, metal

thickness, and electrode size are used to determine amperage setting

Amperage Setting•Amperage too low causes a narrow, high bead with poor penetration

Amperage Setting•Amperage too high caused a flat bead with excessive spatter

Amperage Setting• Correct amperage helps

make a uniform bead with bead width and penetration depth equal to each other

Before Welding•Before metal is welded,

it should be identified, cleaned and cut to correct size (if needed)

Electrode Sticks• If an electrode sticks to the

metal, the electrode should be wiggled back and forth, or it should be released from the electrode holder

Electrode Size• The maximum thickness of

the beveled edge of metal should be the same as the diameter of the electrode used to make the weld

Electrode Size•A 1/8” electrode for a 1/8” thick bevel

Adjust Amperage•Spatter and flat bead are caused by amperage that is too high

Adjust Amperage•A high narrow bead with poor penetration is caused by amperage that is too low

Strike and Arc•Tapping or scratching methods can be used to strike an arc (starts a weld)

Arc Length•Arc length should be the same as the diameter of electrode

Strong Weld•Many different electrode movements or weaves are used to make a bead

Strong Weld• Regardless of the

movement used, the pattern should be uniform to make a strong weld

Travel Speed•If the travel speed is too fast, the welded bead is narrow