s'less TIG welding - "tank" vs. back-purge

s'less welding in a "box" filled with Argon - fanciful or practical?
My intention is to start a TIG welding business doing stainless steel as
my regular work.
"Penetration" stainless welds with just the torch argon supply look
horrible underneath (fillet welds are fine with no other protection? -
they look so if you don't melt through the thickness of the sheets being
joined).
There is back-purge. You would certainly do that for a long butt or
corner-joint.
For more complex shapes which are not long, such as s'less kitchen and
household objects, back-purge is less easy to apply (?) while OTOH the
entire object could be welded in a "box" full of Argon.
That "crozzle" which you get on the top bead even when correctly using
torch shielding -- how is that affected by working in a tank? Do you
have less cleaning to do if you weld in Argon?
Do people have arrangements where they have an air-lock and pass sheet
metal in and finished objects out, thereby limiting the amount of
shielding gas used?
There is Ar/H gas mixes for s'less. If find the market's there, could
imagine having two types of gas (pure Ar for all other purposes). Have
never seen these, but if Hydrogen does for s'less TIG penetration and
heat what it does for "stick" (SMA) it must be useful (?). Are there
any issues to using Ar/5%H with a "box"/"tank"?
(there's an adddition advantage to welding in a "box"/"tank" - I don't
have a dedicated workshop at present and it would be useful to make the
welding unintrusive to those around)
Richard Smith
Reply to
Richard Smith
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I just got through building one for myself. I built it for stainless fittings I weld up for breweries, and for students of mine to use at school for welding Stainless and titanium.
Best of luck. Better make sure there is a need in your area. Don't just asume that you are the only guy to think this up. I say this because it has taken me 7 years to get a decent client list to stay afloat.
You can use a foil backing tape or SolarFlux to reduce the scorching.
I have a pile of purging widgets, from long purge backers for straight weld (3", 6", 9", 12") and a bunch of large jets made from #3 series wide mouth gas lenses. Always coming up with new ones as well.
"crozzle"? I have never heard that term used.
No matter what, if you weld inside an argon filled glove-box you will get no oxidation of either side of the weld.
Mine is a simple acrylic box hinged at the back to a heavy aluminum base plate. To use you lift the box and place your parts inside, hit the argon flow and wait about 5 minutes for the argon to purge the air. Then just weld.
To get ebnough argon flow to purge the box, I swapped the tank connector from a flow-gauge to a oxygen regulator so I can run the argon at 40 psi.
Argon/Helium mixes are common for TIG. I prefer to have a tank of each and simply add helium in when I need it
Hydrogen is never used for TIG welding.
The arc shines through mine in all directions, but you could make one from sheet metal with a window on one side.
Reply to
Ernie Leimkuhler
Here is good thread on making a glove box for TIG welding. Rocky D. works at BF Goodrich Aero Space San Diego and knows about gloove box purge chambers.
Reply to
R. Duncan

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