How to Weld Aluminum with a Spool Gun

What You'll Need
Aluminum to weld
Spool gun
Welding table
Safety goggles
Welding gloves
Face shield
4-inch angle grinder
4-inch flapper wheel
Welding hood

A spool gun is a device that has an attached wire that you can expel it as you are welding. This tool saves a lot of time during your welding projects. A welding spool gun is most used to weld aluminum because the wire never directly touches the surfaces; instead, droplets fall to form the weld. Follow the steps below to properly weld aluminum with a spool gun.

Step 1 - Safety

When you set out to use a spool gun to weld aluminum, you need to be not only safe but thoroughly prepared. Place the aluminum you are planning to weld on your welding table. This is important because using any other type of surface could cause a hazard you could have otherwise avoided. Before you begin, make sure you are wearing your welding gloves, face shield and safety glasses.

Step 2 - Preparation

When you're confident that you are protected, you can attach the flapper wheel to the angle grinder. Put the first piece of aluminum on the welding table. Position it so that one end of the aluminum hangs off of the welding table by about 2 inches. Lower the face shield. Hold the aluminum down with one hand, and turn on the angle grinder. Create a 15-degree bevel on the piece of aluminum. Place the other piece of aluminum on the welding table and repeat.

Lift up the face shield and put on your welding hood. Place both pieces of aluminum on the welding table, and press both beveled edges together.

Step 3 - Welding with the Spool Gun

Put your face shield down again and turn on the welder. Consult the chart that is attached to the machine you are using to weld. This will tell you where you should set the voltage as well as the speed of the wire from the spool gun. The weld joint is where the aluminum was previously beveled. Line up the exposed wire from the spool gun with the beveled joint. Double check to make sure the beveled edges are lined up correctly.

Squeeze the trigger on the spool gun for about 2 seconds to place a tack weld to the joint. Place a tack weld on the aluminum 2 inches apart along the entire area to be welded. Place the spook gun tip at an end to begin with. Pull the trigger, and begin welding the aluminum together at the joint. A weld puddle will form; push it ¼-inch and hold in place for 1 second. Continue in this manner along the weld. Moving the puddle ¼-inch prevents heat from building up or  creating holes in the aluminum.

Step 4 - Handling the Weld

When you reach the end of the joint, you are done welding. The joint you just welded needs to cool down for 30 minutes. At this time, the aluminum will have cooled down enough for handling.