Re: TIG setup for 20 gauge mild steel?

I have some previous TIG welding experience with 1/8" + material. I am now moving to 20ga sheet metal for some auto body work. Here's my question: Would it work to weld 20 ga steel with .040 tungsten and a #4 cup? My thought is a small controlled area would be easier to work withing than a 1/16 tungsten and a 3/4" + Furick cup. All experienced responses are appreciated.

Reply to
N Stewart
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MIG , .025 wire at about 30 amps . I'm not a weldor , I'm a cabinet maker with a metal addiction . Actually , if ya gotta TIG it I'd suggest you stay with the #6 cup and 1/16" tungsten . The amperage has a lot more to do with the weld than than the cup/tungsten size . 1/16" or .050 filler , smaller is better ... too large filler sucks too much heat out of your puddle . But still , I'm not a weldor .

Reply to
Snag

Years ago I was a USAF certified TIG (we called it "Heli Arc" :-) welder and I remember an old civilian welder that used to come in our shop got in an argument about how thin a piece could be welded. He ground a very long taper on the electrode and (I think) changed to a smaller cup and preceded to weld some stuff that was hardly thicker then newspaper :-)

I'd give it a try with what I had, maybe tapering the electrode a bit more and weld some scrap pieces of what you intend to weld and then change to a smaller electrode and cup if that doesn't work.

Reply to
John B.

I have some previous TIG welding experience with 1/8" + material. I am now moving to 20ga sheet metal for some auto body work. Here's my question: Would it work to weld 20 ga steel with .040 tungsten and a #4 cup? My thought is a small controlled area would be easier to work withing than a

1/16 tungsten and a 3/4" + Furick cup. All experienced responses are appreciated.

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I've MIG welded Ford and thinner Honda sheet metal and TIG welded 0.025" wall aircraft tubing (for practice), though neither enough to consider myself skilled. The professional advice I received was to go with MIG for auto body, one reason being to protect the electronics from TIG's high frequency, high voltage. Another is the low penetration and wide weld bead from pushing the MIG gun. You could look for advice on TIG welding aircraft tubing.

I used the same 1/16" tungsten and gas lens on the 4140 tubing that I'd used for thicker stock, without a problem. This was in night school under expert supervision, with my own Lincoln Square Wave 175 since it's what I'd use at home. jsw

Reply to
Jim Wilkins

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