[KYwelder]

So im using an older TIG welder (Miller 330 a a/bp) Makes things harder. The amperage has three ranges (0-50, 15-250, 230-460) and the dial is a percentage of each of those ranges... confusing, yeah? Im welding some 1/4 cold rolled steel that ive grinded to a shine, some 2percent lanthanated 3/32 tungsten, welled sharpened. I have a problem where the arc wanders around. Hard to get a puddle formed. But the real issue is that ive been practicing welding some nuts and bolts the the 1/4 inch and its fizzes alot and bubles up the weld and makes it porus. And this is even if I try to just run a bead down the flat 1/4 plate. Whats wrong? Ive tried different amperages... its hard to set it exactly because its an old welder. Any help would be appreciated, new to the forum so take it easy on me!

[Otto Nobedder]

Welcome!

All that porosity looks like inadequate or no gas coverage.
One thing I don't see in the picture of your machine is a bottle of argon. You do have one, right? 100% argon, not a mix-gas like 75/25?

Steve S

[Oscar]

either that or he can't see the puddle at all and is dragging the tungsten tip within the puddle the whole time. Orange dust of death. Go straight to jail, do not pass Go, Do not collect $200.

[KYwelder]

Otto, Yes i have 100% argon. The pic of the welder is just so you know what machine I have, at time of picture i didnt have argon or any setting adjusted. I tried around 15cfh and up to 30cfh, no difference, ive been practicing on some stainless 16g and my welds arnt perfect but atleast the arc doesnt wander and its not porous at all. From some research ive figured i maybe have TOO MUCH gas? Using a number 7 cup, arch lenght is maybe 2mm away from puddle.

[Otto Nobedder]

Interesting that it behaves fine on stainless, but is a disaster on the mild steel. 15 -20 CFH should be fine, and 30 should not cause this. I wonder about the alloy of your cold-rolled... You've obviously got it clean enough, but it looks like crap is boiling out of the metal. Could your grinding disk be contaminated? Say from grinding on galvanized steel, or accidentally getting sprayed with WD-40 or something?

Steve S

[KYwelder]

For future reference, do you weld stainless sheet? (incase i have issues )

Id never think to check the flap disk, but it's actually new, i did grind a few stainless rectangles to practice on... Would the cold roll vs hot roll steel make a BIG diferance?

[Otto Nobedder]

I weld a lot of stainless, ranging from 1/2" down to 11 ga., pipe from XXS down to sch. 5, but rarely 16 ga. sheet, and then it's usually stitched lap welds, not seams. Others here do have a lot of experience with thin SS sheet, and will be better guides than I on that subject.

Cold-rolled versus hot-rolled should make no difference at all (other than having to remove the mill scale). I'd suggest two experiments. First, grind a section of the cold-rolled with a hard stone, to rule out the flap-disk. Sometimes the glue holding the abrasives can contaminate the metal, if the grinding gets hot enough or the disk is cheap enough. I'd also try some other samples of scrap steel to see if it's the particular steel you're welding.

Now for the really dumb question (I know I asked a few in my first reply)... You're set in DCEN, and do not have high-frequency on (or if you're in hf-start, the hf is disengaging when the arc is established), right?

(Without knowing your level of experience, we'll always try to rule out things that may seem obvious.)

Steve S

[KYwelder]

Well i just tried another piece of steel... same issue, tried some stainless again and works fine. And im actually set on dc straight so i guess thats DC positive. And the HF is set on start, not continuous.

[GreinTime]

Well i just tried another piece of steel... same issue, tried some stainless again and works fine. And im actually set on dc straight so i guess thats DC positive. And the HF is set on start, not continuous.

DC straight is typically referred to as DCEN, DC Reverse is DCEP.

Sent from my SM-G900V using Tapatalk

[thespian]

Hit the pedal with the torch near your ear , do you hear gas? Wondering if you have a big leak somewhere?
Is your tungsten eroding really quickly? The curve ball you are throwing is that it works on stainless.

[Jim FLinchbaugh]

the plating on nuts/bolts/fittings will do that exact thing, ie, "the orange crust of WTF."
you cant grind enough off to have anything left to weld IMO.
Last week I tried grinding the galvanize of some conduit to use the tubing, and that crap sucked straight up the cup and fouled everything even though you couldn't see it on the metal