Sheet Metal Welding – Tips and Techniques

Guys, I want to finish up the last post on sheet metal welding tips. I ran out of space in that one, so I want to finish it up before I move onto some techniques to perfecting the weld. Now these sheet metal welding tips are mostly safety related. I know a lot of you will roll your eyes, but guys seriously, this stuff is important. I know us welders overlook this stuff, but it is always good to keep this stuff in mind when TIG welding pipe or whatever other welding we’re doing.

I’ve seen guys do this. Blow themselves off with oxygen from their cutting torch. This is so dangerous, guys just aren’t thinking when they’re doing it. You might as well be dousing yourself with gasoline. So what if you have some metal filings or other things stuck to your clothes. Brush them off if you must. But to potentially set yourself up as a human torch is insanity.

When MIG welding or doing any welding for that matter, make sure you keep your pockets empty. At the very least, make sure that you don’t have any matches or lighters in your pockets. This is just asking for trouble. I’ve never actually heard of someone burning themselves this way, but all it takes is a little inert gas leak, a little spark and you’ve set yourself up for a nasty burn or more.

Lastly, don’t use your oxygen tank to fill up your tires. This a really bad idea. Oxygen can explode, build up heat and is jut not meant to be in tires. Make sure you always have a spare so that you are never tempted.

Okay let’s get to some real sheet metal welding techniques. I want to give you a couple of tips on making a great weld with metal inert gas welding or MIG welding. As most of you know the biggest problems with sheet metal welding especially when MIG welding thin sheet metal is not burning through the metal while creating a strong weld, and also watching for warping and the presentation of a nice clean weld.

So when sheet metal welding use the thinnest wire possible. This will help in keeping the temperature down and giving you better control over the weld. A good rule of thumb is to use a wire of .023 inches in diameter when sheet metal welding a metal that is .04 inches thick or less. Sheet metal thicker than .04 inches can be welded with wire of .030 inches in diameter.

When sheet metal welding try and use the highest possible argon shielding gas. Argon carries less heat than carbon dioxide and this will dramatically reduce the metal spatter which can leave an ugly weld.

This sheet metal welding tip especially for sheet metal MIG welding will sound counter intuitive, but try it, it works. Keep the arc in the middle of the puddle to protect the base metal from the full brunt of the arc’s heat. This is not common practice but will yield very nice and clean welds.

In arc welding sheet metal, weld in a straight line as fast as possible while maintaining a good bead profile. In sheet metal welding, weaving or whipping the torch will not create a clean weld and will cause undue heat stress on the base metal.

The last technique to use for a great sheet metal weld is to use skip welding. This is a great technique not just for sheet metal welding but other welding jobs too. The idea here is to weld 1 inch at a time and skip ahead 5 inches along the complete length of the sheet metal welding job. This helps maintain even heat along the complete weld profile and will set you up for a very nice clean and smooth weld.