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Stick or ARC welding stainless steel requires the use of a welding rod that is compatible with the chemical makeup of the stainless steel you are welding. You can use a higher purity stainless steel welding rod for lower grade stainless steel, but not vice versa. For example, a 316L rod can weld 304-grade stainless steel, but you cannot produce a weld with structural integrity using a 309L rod to weld 316-grade stainless steel; this is due to crystalline structures that form in the weld joint.

Instructions

1

Place the two pieces of stainless steel flat on the welding table, with the sides that need to be welded resting 1/16 inch apart. Secure the pieces of stainless steel by clamping them to the welding table with self-locking clamps.

2

Turn on the ARC welder and adjust the amperage for the size thickness and type of stainless steel welding electrode you are going to use to weld the stainless steel.

3

Put on your safety glasses, welding helmet and heavy leather welding gloves. Clamp a stainless steel welding electrode in the stinger of the ARC welder and connect the ARC welders ground clamp to the welding table.

4

Align the welding electrode with the joint between the two pieces of stainless steel and lower your welding helmet.

5

Strike and lift the welding electrode on the stainless steel joint to start the ARC between the stainless steel pieces and the welding electrode.

6

Work the electrode over and down 1/8 inch, then back over the weld joint to weld the two pieces of stainless steel together.

7

Remove your welding helmet and tap the weld with the chipping hammer to remove the slag from the stainless steel weld.

8

Allow the weld joint to cool thoroughly before you handle the welded stainless steel--the weld joint will be hot and can cause severe burns.

Polyurethane was first developed in Germany during WWII as a synthetic replacement for rubber, and was patented by Dr. Otto Bayer in 1937. Polyurethane is commonly used to make tires, shoes, insulation, bumpers, spandex and catheters. All polyurethanes are based on the reaction of organic isocyanates with compounds that contain a hydroxyl group. The two groups of polyurethanes are thermoset (PUR, RIM or RRIM) and thermoplastic (TPU) and this difference affects the way that each one can be welded. Both are common as automotive pieces, especially bumpers.

Instructions

Welding Thermoset Polyurethane

1

Identify which type of plastic you have by heating the plastic welder to max and touching it to the back of the piece of plastic. If it is thermoset polyurethane, it will smoke and discolor and once cool it will still be sticky. Thermoplastic polyurethane will not smoke and discolor and once cool it will not be sticky. If the plastic is thermoplastic polyurethane, proceed to Section 2 for welding directions.

2

Align the broken pieces together with clamps or aluminum body tape. Apply the tape on the finish side of the piece. With a teardrop bit on the air die grinder, grind a V-groove along the complete break halfway through the break.

3

Turn the airless plastic welder to the lowest setting for R1 repair rod and allow it to heat up. Insert the rod through the welding shoe. Hold the shoe off of the base plastic and allow the melting plastic fill the V-groove. The process is more akin to brazing or soldering than welding. Fill only about 2 inches of the V-groove at a time and let it cool.

4

After completing the V-groove on the back side of the piece, remove the aluminum tape from the finish side and make a V-groove halfway through from the finish side. Sand the slick finish off with the die grinder and a Rolex sanding pad.

5

Fill the V-groove from the front as directed above. Sand the fill flush with the Rolex pad. The part is now ready for finish work and painting.

Welding Thermoplastic Polyurethane

6

Align the broken pieces together with clamps or aluminum body tape. Apply the tape on the finish side of the piece. With a teardrop bit on the air die grinder, grind a V-groove along the complete break halfway through the break.

7

Turn the airless plastic welder to the setting for TPU repair rod and allow it to heat up. Insert the rod through the welding shoe. Lay the shoe on the surface of the base plastic and allow the melting plastic rod to fill the V-groove. Fill only about 2 inches of the V-groove at a time and before it has time to cool go over the area with the welder to make sure the base material and rod are melted and blended together. Continue this process until the whole break line is filled and welded.

8

Remove the aluminum tape from the finish side and make a v-groove halfway through from the finish side after completing the backside of the piece. Sand the slick finish off with the die grinder and a Rolex sanding pad.

9

Fill the V-groove from the front as directed above. Sand the fill flush with the Rolex pad. The part is now ready for finish work and painting.

Welding thin steel exhaust tubing requires patience and the correct equipment to get a sealed weld. The difficult part of welding thin walled steel tubing is maintaining your weld puddle without overheating the connection will result in the puddle melting through the tubing. With a properly set up MIG welder and a little practice, you easily create a sealed weld joint on the thin diameter steel tubing. MIG welders are widely available at rental stores or for purchase at your local welding supply retailer.

Instructions

1

Read the owners manual for the welding machine to determine how to change the feeder wheels over to accept the .023 welding wire.

2

Spool the welder with the .023 solid welding wire after you switch the wire feeder wheels.

3

Open and close the valve located on top of the bottle of shielding gas to clear dirt and debris from the threaded area.

4

Turn the threads of the MIG welder gas regulator clockwise to attach the regulator to the bottle of shielding gas. Set the adjustable wrench to fit the regulator nut and lock the nut to seal the connection. Open the valve to send gas to the MIG welder.

5

Turn on the welding machine and place the grounding clamp on a piece of metal.

6

Point the tip of the MIG gun at the metal and depress the trigger of the MIG gun. Listen to the sound coming from the weld area between the MIG cup and the grounded piece of metal. Adjust the heat and wire speed settings until you hear a sound similar to eggs frying in a pan.

7

Place the ends of two pieces of steel exhaust tubing tightly together and ground the steel tubing with the grounding clamp.

8

Wearing your safety glasses, place the end of the MIG wire protruding from the tip of the MIG gun against the center of the weld joint and depress the MIG guns trigger for 1 second to create a tack weld. Roll the pipe, placing tack welds around the weld joint.

9

Put on your welding helmet and welding gloves.

10

Rest the wrist of the hand that you are holding the MIG gun with on a firm flat surface and grasp the tacked pieces of pipe with the other hand.

11

Align the wire extending from the MIG gun with the weld joint, flick your head forward to lower your welding helmet, and depress the trigger of the MIG gun.

12

Move the MIG 1/8th of an inch and stop to let the weld puddle build, when the weld puddle reaches around 1/8th of an inch tall, move the MIG gun another 1/8th of an inch. Continue the process, turning the pipe as needed to expose more weld joint until you weld around the entire weld joint and reach the spot where you began welding the joint of the steel tube.

13

Allow the joint to cool thoroughly before you move the welded tubing.