How to Weld Sheet Metal

The two popular types of welding are spot welding and seam welding. Sheet metal is best welded using spot welding, because spot welding concentrates the welding into a small area of the sheet, reducing damage and minimizing the time it takes to heat up the metal and cool it off. Most likely, the material will not be damaged if the welder is performing the job properly, and the equipment is from an established supplier of welding equipment. Welding sheet metal is the easiest type of welding, requires less work, and is simple enough even for those who have never stepped foot in a metal shop.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Portable spot welder (optional)

1. Lay two pieces of sheet metal, both with equal thickness, on a flat surface work area. Avoid wood.

2. Flatten your sheet metal with a soft mallet/rubber hammer until the surface is as flat as you can get it.

3. 

   Place your sheet metal on the work area of the spot welder. Position the sheet metal under the two electrodes on the spot welder. Preferably, use practice metal or spare sheet metal for testing the weld. Make adjustments to the voltage on your welder as necessary.

4. Place aluminum sheeting under your welding area to catch any potential liquid metal. This is particularly good if you are using the portable welder and do not have a full shop of welding machines.

5. Turn on the power, then press the button to weld. Hold for a couple of seconds only. The current will not likely exceed 1.5 volts. Continue welding from the edge, then the middle, then the other edge of the sheet metal. Spread out your weld spots for best results.

Tips & Warnings

• Use higher welding current for aluminum sheets. You may have to turn the voltage down near the end of your project, as heat/electrical resistance changes.
• If your sheet metal warps, increase the distance between each spot where you welded. Secure the ends and the middle of the sheet metal with a few spot welds to hold the parts in position.
• Keep the work area clean of fire hazards and flammables. Wear protective gloves, goggles or welding helmet and a protective apron.

Resources

• Portable Spot Welder
• Miscellaneous Welding Supplies
• High Tech Welding Machines