Welding Tips and Tricks

Hi everyone

Beginner question here .. I've been upping my TIG welding game for about 2 years now and one issue i struggle with when welding thin body panels is oxidation.
I tend to get nice and shiny beads when welding 16GA or thicker. With thinner sheets (20 GA and thinner) I've been struggling. Tried various gas lenses + cups, gas flow and tried to be on the very low end of the amperage. They have gotten better but nowhere near how my "thicker" welds look like. The heat affected zone also seems to be wider when compared to the weld itself.

Is this mainly because of overheating ?

Thinner materials are easier to overcook I get that part but there seems to be no sweet spot where I can get a workable puddle size without putting too much heat

Is this just the way things are? anyone with similar outcomes? any tips or pointer on what to try to fix/tweak?

Two factors to consider: your arc length and filler wire size. Thinner material prefers thinner filler. This allows you to lower the overall heat.

If the HAZ is wider, then you’re likely running too long an arc length thinking (in reverse) that farther away is a cooler arc. This is actually the opposite of reality. Just about touching the puddle keeps the arc cone tight and focused. A tip on your tungsten ground to about 30* creates a tighter arc as well.

Maybe post up some pictures and that might reveal some other issues.

the other factor is also travel speed. if you wind down the amps a lot thinking your going to cook it, you end up travelling slower which overheats the material and gives that wider haz.
adjust your travel speed more than your amps.

for me, using pulse helps a lot. either a high pulse rate to be able run higher amps setting as some machines can have poor control at lower amps, or use low pulse settings.

And of course there's no getting away from the fact that thin sheet metal just is a lot harder to work with. Welding in short 'bursts' and letting it cool helps a lot.

You may need some form of heat soak material, like Jody showed in several of his videos, such as a copper/alu/brass backer to draw some of the heat away from the steel and stop the HAZ from spreading out.

Also with thin metal, better get up to speed with some (sheet) metal working tools like dollies and shrink and stretch hammers as it will want to warp/deform no matter what you do and will need some 'massaging' back into shape. Back-stepping and jumping around on the weld as well as cooling it helps to even out the distortion, but it will remain somthing to work on.

Bye, Arno.