TIG setup for 20 gauge mild steel?
Jeffrey Nelson
TIG? I've got a Sychrowave 180 and the smallest collet I've got is 1/16
inch. Dan Covell has suggested elsewhere that 1/16 inch tungsten, and 0.035
inch wire will work. Can I use MIG wire instead of "real" TIG wire? The
application is not too critical, it is mending the sheet metal engine
shrouding for my Porsche/VW 914.
Ernie Leimkuhler
"Jeffrey Nelson" <jeke...@earthlink.net> wrote:
A 1/16" tungsten should be fine.
0.035" MIG wire is ER70S-6 wire, which will work OK for TIG.
20 ga steel is around 0.038" thick so start with your machine set for 40 amps.
If you aren't worried about color match or will be painting it, then use 308L
stainless steel filler wire.
The welds will go smoother and you will have less chance of porosity from
contaminants.
--
--
The difference between genius and stupidity is that genius has it's limits....
(Albert Einstein)
S. Ztrauq
"Jeffrey Nelson" <jeke...@earthlink.net> wrote in message
news:4Lg99.1874$ob2.1...@newsread1.prod.itd.earthlink.net...
Use 1 amp per .001" thickness, off the top of my head I think 20 gage is
about .040", so figure 40-45 amps. I use mig wire for this kind of thing
regularly. I have a 1 pound spool of Hobart ER70-S6 that I use for tig
welding. ER70-S2 would be better, but I've so far been unable to find it in
spools or in cut lengths smaller than 1/16" diameter.
If you're going to do much sheet metal work, it would be worth your while to
buy a .040" collet and a couple of .040" lanthanated tungstens. That would
set you back less than $15, maybe a few bucks more of you're using a gas
lens.
-S.Z.
brad
same. Just depends if it is wound on a spool or is in a cut length. All tig
wire starts life as a spool or coil (500-1000 lb) and is run through
straighteners to make the cut lengths.
Often you can save a bit of money buying the small diameter wires on small 2
lb spools and straighten out yourself, although this can be a pain if you
have a lot of welding to do.
For your application, ER70S-6 would work better than the old standby,
ER70S-2 as the -6 wets out a little easier.
A 1/16 2% or Ceriated tungsten, ground to a slender point will work as well
as anything. Stay away from the smaller stuff (.040, .020). It gives no
advantage over a properly pointed 1/16 tungsten.
If burnthrough is becoming a problem, switching to AC with a small (1/16 or
3/32) pure or Zirconiated tungsten can help. It gives a wider, softer arc
and is not so ready to burn through like the sharp needle arc of the DC. If
your squarewave machine has an adjustable balance, experiment a little to
get a stable arc.
I get a repeat job doing butt welds and outside corner welds on .035
stainless and have found the AC trick useful.
Good Luck-brad
Jeffrey Nelson <jeke...@earthlink.net> wrote in message
news:4Lg99.1874$ob2.1...@newsread1.prod.itd.earthlink.net...
Eric D
> 3/32) pure or Zirconiated tungsten can help. It gives a wider, softer arc
> and is not so ready to burn through like the sharp needle arc of the DC. If
> your squarewave machine has an adjustable balance, experiment a little to
> get a stable arc.
Brad, what is a typical positive to negative percentage on your
balance adjustment or could you suggest a good starting point?
> I get a repeat job doing butt welds and outside corner welds on .035
> stainless and have found the AC trick useful.
I've never tried AC for stainless before. Looks like you have given
me something to play around with on the welder. Thanks!
Eric D
Mike Graham
> What's a good setup for butt welding 20 gauge mild steel sheet metal using
> TIG?
I know the rule of thumb is 1 amp per thousandth, but when you're doing a
butt weld without backing of any kind, unless the fitup is perfect I'd be
running 30 amps or even 25 amps rather than 40 amps. If you've got a remote
on the amperage then you can set your machine to 45 amps and just use the
remote to give you what you need.
Someone else mentioned using AC. This is awesome on *thin* stainless. Up
to .050" or so but I prefer DCSP for mild steel... AC isn't recommended for
mild steel over .030", so your material is a bit too thick for it, really.
Straight argon gas is best for this skinny material.
--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Fighting the good fight against porosity,
mi...@metalmangler.com | lack of fusion, and people who constantly
<http://www.metalmangler.com>| try to correct the spelling of 'weldor'.
Mike Graham
> If burnthrough is becoming a problem, switching to AC with a small (1/16 or
> 3/32) pure or Zirconiated tungsten can help. It gives a wider, softer arc
> and is not so ready to burn through like the sharp needle arc of the DC.
This is true, but AC isn't normally recommended for mild steel over .030"
thick. If burnthrough is a problem he should probably turn down the
amperage.
Ted Edwards
> This is true, but AC isn't normally recommended for mild steel over .030"
> thick. If burnthrough is a problem he should probably turn down the
> amperage.
Ac is recommended for aluminum because of the cleaning action. Thye
only reason I can see against using it on steel is the higher efficiency
resulting from delivering more heat to the work and less to the
tungsten. Is there any other reason?
Once I've got the current as low as I can, the ac trick might let me get
the heat down for really thin stuff.
Ted
Ted Edwards
> to .050" or so but I prefer DCSP for mild steel.
Why to people insist on sticking do this rather stupid, obsolete
terminology? Is it to differentiate between straight and bent
electricity? Every DC welder I've seen has a + and/or - sign on the
terminals. Why not just refer to E+ or E-?
Ted
Mike Graham
> Ac is recommended for aluminum because of the cleaning action. Thye
> only reason I can see against using it on steel is the higher efficiency
> resulting from delivering more heat to the work and less to the
> tungsten. Is there any other reason?
Wider puddle meaning more heat/distortion for a given depth of
penetration.
> Once I've got the current as low as I can, the ac trick might let me get
> the heat down for really thin stuff.
Well, 'not recommended' certainly doesn't mean 'won't work under any
circumstances'. If you're welding stuff that you can't 'get under' then you
do what you have to, up to and including running DCRP.
Ted Edwards
> For your application, ER70S-6 would work better than the old standby,
> ER70S-2 as the -6 wets out a little easier.
I had the impression that -2 had better/more deoxidizers. Is this
wrong?
Ted
Mike Graham
> I had the impression that -2 had better/more deoxidizers. Is this
> wrong?
-6 has the most comprehensive deoxidizer package. Whether you *need* that
comprehensive a package is a tough question to answer. -6 is about the best
of the hardwires that I've used for welding over rust, scale, etc.
N Stewart
> --
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Mike Graham | Fighting the good fight against porosity,
> mi...@metalmangler.com | lack of fusion, and people who constantly
> <http://www.metalmangler.com>| try to correct the spelling of 'weldor'.
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.
Snag
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 .
--
Snag
"You can lead a dummy to facts
but you can't make him think."
John B.
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.
--
Cheers,
John B.
Jim Wilkins
news:5f41d37d-a57d-4007...@googlegroups.com...
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