TIG welds foaming

Greetings all:
I've read Richard Finch's book on welding, and actually have been welding
for many years, but one thing still gives me a problem. When I TIG weld
mild steel, my welds sort of "foam up." I'm using argon as the sheilding
gas, and I've tried increasing the flow, larger and smaller cups on the TIG
torch, and using both thoriated and non-thoriated electrodes. I use
high-quality certified welding rods. I've tried welding slower to keep the
argon over the weld longer, but no luck. This happens mostly when I'm
welding thick 1/4 inch material. Everything is clean. No drafts to blow the
argon off he weld. Tried both DC electrode negative, positive and AC.
What am I doing wrong?
Thanks for all. You can even flame me if you like. I like it.
JM
Reply to
John Magnus
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Somehow your gas is not getting to the torch. Check your hoses and fittings to make sure you aren't sucking air in along the way. Make sure you are holding your torch in close. If you are using a standard collet body you can extend the tungsten 3 diameters past the edge of the cup. 3/32" x 3 = 9/32"
Make sure all firescale is ground off the metal. The steel must be clean. No paint, oil, rust, scale, glue, whatever.
Make sure your filler rods are clean.
Reply to
Ernie Leimkuhler
Oh yeah, it could just be a bad bottle of gas. It has happened twice to me in 10 years. It can drive you nuts until you figure out it is the gas.
Reply to
Ernie Leimkuhler
: :> Greetings all: :> :> I've read Richard Finch's book on welding, and actually have been welding :> for many years, but one thing still gives me a problem. When I TIG weld :> mild steel, my welds sort of "foam up." I'm using argon as the sheilding :> gas, and I've tried increasing the flow, larger and smaller cups on the TIG :> torch, and using both thoriated and non-thoriated electrodes. I use :> high-quality certified welding rods. I've tried welding slower to keep the :> argon over the weld longer, but no luck. This happens mostly when I'm :> welding thick 1/4 inch material. Everything is clean. No drafts to blow the :> argon off he weld. Tried both DC electrode negative, positive and AC. :> :> What am I doing wrong? :> :> Thanks for all. You can even flame me if you like. I like it. :> :> :> JM
: Oh yeah, it could just be a bad bottle of gas. : It has happened twice to me in 10 years. : It can drive you nuts until you figure out it is the gas.
Reply to
tmiller
I've run into that. I found that steel that just won't work with a mild steel filler will usually work ok with 309 or 312 stailess filler.
Ted
Reply to
Ted Edwards
In message , John Magnus writes
Hi Magnus,make sure you are using the correct filler.The filler rod for gas welding mild steel is not suitable for TIG welding,it leads to large amounts of porosity in the weld metal.TIG welding filler has larger amounts of deoxidants.
Reply to
Gwyn Phillips
So, what is the reccomended tig filler? I think I have E70s-6??
Reply to
James Arnold
That's fine. All MIG wire is fine. If it's the right wire for MIG then it's the same right wire for TIG on that material.
Reply to
Zorro
Actually, you probably have ER70S-6. The "E" part means it can be an electrode and the "R" part means it can be a feeder rod. Only McGyver could use 36" cut rods in a MIG but it's ok to use MIG wire off the roll for TIG.
Note: Not that you were going to, but for reference, don't try this with flux cored wire. You'll notice flux cored wire does not have the "R" part in the class name. It's usually something like E71T-GS. The "T" meaning tube.
Reply to
Zorro
Thanks, Zorro..
Reply to
James Arnold
Hmmm, out of morbid curisoity, what _does_ happen when TIG'ing with flux-core wire? Sounds like a really bad idea...
Reply to
Rich Jones
I don't know. I haven't got a TIG of my own or else I'm sure I would have tried it by now. I've tried using 16penny nails in the stick welder. It was no fun at all. ;^)
Reply to
Zorro
Thanks all for the advice. I bought some E75 rods today and tried them; I saw some improvement, but still some foaming. I was a little annoyed that the welding shop only had copper coated rods, as Finch's book suggests avoiding them.
I've turned the argon flow rate so high that I know I'm wasting it. On a guess, I tried using a non-thoriated, pure tungsten electrode and the welds look much better. I also tested another theory by deliberately plunging the thoriated electrode into the weld puddle. I noticed it exacerbated the foaming noticeably, and when I re-ground the electrode, the foaming was less. With the contaminated electrode, near the end of the weld, as I stopped the arc and during the afterflow, the puddle actually foamed up to form a little peak until it solidified.
I don't know the basis for this, as I've read that thoriated electrodes are supposed to be used when welding steel, and pure tungsten used when welding aluminum.
Any ideas why this is working or has anyone noticed a similar effect?
Thanks, John
Reply to
John Magnus
I have done it with dual shield hardfacing wire. It is a bit messy, but works. The problem is the sodium flare from the flux is quite bright in the TIG arc.
Reply to
Ernie Leimkuhler
Either you ahev really bad gas or really bad steel.
Reply to
Ernie Leimkuhler
Hey Ernie,
Could he also be overheating the puddle; boiling the steel?
Jeff
Ernie Leimkuhler wrote:
Reply to
jeff
If the base metal, shielding gas and filler rod were clean it wouldn't matter how hot he got it. Somehow oxides are getting into the puddle.
Reply to
Ernie Leimkuhler
Are you Mister Wizard or part of the Sesame Street cast? Keep up the good work your saving some people alot of typing. :)
Reply to
PROFESSORLITE
Hmmm. That's news to me. Since TIG uses an inert gas atmosphere while oxyacetylene welding does not, the need for deoxidants should be *less* with the TIG process. I've used RG45 for years in both O/A and TIG welding.
Gary
Reply to
Gary Coffman
Try using copper clad filler rods. Works for me.
Reply to
jerzyjer

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