Tips For Welding Sheet Metal
March 26th, 2019
As you know, when welding there is a lot of heat. But what you might not know is that if there's too much heat on a metal part it can actually cause it to distort and bend. And while in real-world use you might not have enough heat to damage thick metal like a frame or roll cage, it's still good practice to manage heat input. Sheet metal, on the other hand, is very easy to damage and warp. So here are some tips and tricks for welding sheet metal.
First up, what not to do. LT starts the patch like normal, by tacking one edge and working his way around the outside keeping the patch even with the hood. When the welding gets started is when things go wrong. He works in one direction, working his way around the seam. And while it may look neat and smooth, this method leaves a big gap in the middle if you lay a straight edge across it. If you tried to repair that with body filler, you'd have a massive section covered so that you could smooth out the high and low spots.
A better way to do it is by starting the same way but then do several quick tacks when you start welding spaced in between the first welds. After around a half dozen are done, use some compressed air to cool the area down. When it's cool enough to touch, go ahead and do another round of tacks spaced in between the existing welds. Repeat this process of tacking and cooling until the entire patch is burned in. The same thing applies when grinding down welds.
With patience and heat control you'll end up with a nice, even surface.