Problems With Overheating Your Stainless TIG Welds?

Grey and Overheated Stainless TIG Welds? Here’s What You’re Missing

Ever finish a stainless weld and it comes out dull, crusty, or just plain sad? You’re not alone—and here's the thing, it’s not always your amps. The real issue? You’re probably not feeding enough filler.

Let’s talk about how to keep your welds shiny and avoid that cooked, overheated look.

Filler = Heat Control

Say you’re welding a simple butt joint on 3.2mm (1/8") stainless. Settings are dialled, gas is flowing, and things start great… until halfway through the weld, things go south. The puddle flattens, edges sink, colour turns grey.

It’s not always your machine—it can be the amount of filler you’re adding.

Not Just Filler—It’s a Heat Sponge

Filler rod isn’t just there to “fill the gap.” It’s also one of the best tools you’ve got to reduce the overall heat input into the base material. Not enough filler? Even with a perfect amp setting the heat builds up and the joint overheats—especially near the end where heat builds up.

You’ve got two solid options when things start getting hot:

• Back off the amps (if you’ve got a foot pedal)

• Add more filler and let it take the heat

And honestly, option two is usually the one I'd pick if I had to pick just one, but a lot of the time a combination of both options is the best.

What Happens When You Don’t Add Enough

If your weld starts to dip and looks concave, that’s your puddle screaming for more filler. No reinforcement = no strength and no shine.

But when you feed enough filler right from the get go, and keep that reinforcement up..? You get a clean profile, better fusion, and way less oxidation. The heat buildup is a touch less, and your gas has a much easier time of doing it's job.

Watch the Puddle Like a Hawk

You’ve gotta keep an eye on what your puddle is doing. If it’s sinking or hollowing out, you’re behind. Start feeding more. And don’t be scared to double-tap that filler if things heat up quick—especially near the end of the run.

Travel Speed Matters Too

Moving too slow? You’ll cook it. But enough filler can actually help balance that out. So yeah, speed and filler go hand-in-hand. Stay steady, but if things feel hot—feed faster or more often.

Need More Reinforcement? Go Bigger

If you’re constantly getting flat welds with 1.6mm (1/16") filler, maybe it’s time to step up to 2.4mm (3/32"). Having that extra material ready helps you react faster when the heat ramps up.

Final Wrap-Up

If your welds are looking dull or grey, it’s not always your settings—it might just be a lack of filler.

Think of filler rod as a heat control tool, not just something you feed in because you’re “supposed to.” The more you understand how to balance your speed, heat, and filler, the better your welds will look—and the stronger they’ll be.

If you’re more of a visual learner, I’ve got a full lesson on this exact topic over on my YouTube channel. I walk through the filler technique, show live weld examples, and break down exactly how to avoid overheating. Go check it out if you want to see the difference in real time - Watch The Episode Here

Keep practicing. Watch the puddle. Add filler like it’s your job—because it kinda is.

Stay kind, stay chill,
Dusty