Welding Tips and Tricks

I've noticed when TIG welding aluminum that my beads are usually proud, meaning, they sit higher than the base metal.

I TIG welded some mild steel yesterday, 1/8" thick with 70S-6 and no matter how much rod I applied, the welds came out flush with the surface. It was a good bead, that is it looked like a weld bead, but it wasn't sitting proud at all. And these are butt welds in case there was a question. The welds weren't concave, but almost.

I don't even think this is an issue strength-wise. For my application, the mild steel that I was welding is definitely welded with full penetration but I did have the question as to why the weld sat so "low" if you will. Was it:

1. Too much heat? But if I applied any less I probably would only have partial penetration.

2. Too sharp an angle on my tungsten creating too broad a heat zone? I've heard that the sharper the tungsten, the more your arc and therefore heat will spread. Any truth to that?

3. Moving too slow and letting the piece heat up too much? I'm welding 1.5" x 1.5" angle.

4. Or something else?

5. Or nothing to get too worried about?

I'm not losing sleep over this but if I'm going to get an answer anywhere, it's probably here.

THKS.

Jon

I'm sure you'll get better answers with more information than what I have but steel is fundamentally different from aluminum and this feature of lower sitting welds is one of those fundamental differences. It's going to be lower than aluminum by default, no blame to technique or settings.

However, your technique and settings can be used to overcome the natural difference in steel and you can work at getting a good mole hill, as I like to call it. Just put more filler metal into the dab with a little more heat but the same speed and it should stand up a little higher I think.

I believe that because aluminum melts so much easier, in one dab there is so much more metal going into the weld instead of steel melting only a little bit, relatively.

tG - Thanks. That helps. Funny - I get better "mole hills" (I like that, I'll take it!) when I'm fillet welding than when I'm butt welding. And you're right, a slight change in technique gets me a better weld profile.

And steel, for me, is so damn sticky. Way stickier than aluminum. With steel I really have to aim for the center of the puddle to keep that rod unstuck.

Thanks again!

Jon

It just sounds like it's cold if the rod is sticking frequently. The secret to stainless and mild steel is going hotter and faster. You can only go as hot as you can go fast though. So I'd increase the amps slightly and try and keep up, burying the filler in as you go. Then increase the amps again until it is no longer sticking so easily and you are able to keep pace with it and the shape of the weld still remains up.

steel should not be sticky. add filler to the front of the puddle.
stainless can be a little sticky.
with aluminum you can do the sink method i think its called where you wait a bit until the puddle sinks then add filler to raise it up.