argon backing for stainless

[ryanjones2150]

How about some suggestions or ideas on building some sort of argon backing doodad for welding stainless sheet...

Here's what I have to do...some 20ga stainless sheet fab work to get done, a couple of long welds (48" and 21").

Was looking around for some sort of argon backing fixture I can make that is small enough to be portable if need be yet big enough so I don't have to move it every two inches of weld. I usually use either aluminum or copper as a backing when I weld stainless, but thought I'd try something different.

I will be using the TIG process with 2% lanthanted 3/32 tungsten.

Anyone have any pictures or ideas of a device as such they'd like to share?

[WillieB]

I don't have pictures. G. H. Grimm co in Rutland VT makes Maple Syrup equipment. They once used solder for all their joints. Now, because of lead concerns, they TIG everything. Each new shape for a joint is done with a machined backer of aluminum. The exact shape is machined with provisions to clamp. It isn't a good option for me, I haven't the equipment for machining. I seldom build the same item twice.

[ryanjones2150]

argon backing for stainless

Same for me. So here's my last eat idea...a piece of square aluminum tube, flatten one corner edge, drill a series of holes down the edge, cap the ends, weld in a bung then thread in a gas nipple for the argon. Make it maybe 10" long. I think it might work.

[ryanjones2150]

Here's one of the pieces I'm making all tacked up. It's a top to a chest type cooler. There is a door that just sits on top that slides off when they need in. Around that inside edge I have to build up around a 32nd-ish of filler metal to make a little lip all the way around. When it's done, this piece will just simply slip over the top of the existing cooler and I'll screw it in place.

[MMW]

First I'm glad it's you & not me welding that up. Probably get a lot of warpage. Hopefully not but watch as you go to limit it as best as possible.

You can make a quick argon backer with tin foil & tape. Make a small tent to cover everything & tape all the sides far enough away from the haz so the tape won't burn. Stick a hose at one end & make a hole at the other.

[ryanjones2150]

argon backing for stainless

Hmmm...sounds easy enough. Pretty much like masking off for pipe welding. I have no doubts that this thing is gonna warp like crazy. I'm planning to back step my way around it, taking my time and such. As long as I can beat it back into shape-ish before I screw it down, I think it'll work. We shall see. I'm gonna put it off for a day or so yet to hear some other responses if they come in.

[kiwi]

Ryan,
Have you ever used Solar Flux? Here is a link to it.
Nick

http://www.solarflux.com/Pages/Productinfo.html

Here is a quote from the website.
"A USER'S COMMENTS

The following is the content of a letter mailed to us.

"The project is a new High Explosive Synthesis Facility. The process and the stainless steel piping is complicated. Quality control is essential. We set up to test a 3-inch 316 open butt weld at the 6g position using SOLAR FLUX in lieu of argon purge gas. I was amazed as I watched the stringer bead being welded. The joint was excellent. We had to have x-ray quality. The radiographer's first shot was an elliptical view and it was perfect. Then I asked for a contact shot and it, too, was perfect. I highly recommend SOLAR FLUX without hesitation."

J. R. Talley, CWI
Quality Control Superintendent
Kimmel Mechanical, Inc."

[ryanjones2150]

argon backing for stainless

I have heard of it, but that's about it. I'll take a look at that link, thanks for the feedback. Have you used it? Has anyone else?

[WillieB]

I wasted $55.00 on Solar Flux. It didn't work. I may have mixed it with too much alcohol though, but I ruined the piece.

[elvis]

I've messed around with solar flux. It seems to be fine. It is a son of a ***** to get off once you are done welding.

[ryanjones2150]

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[ryanjones2150]

argon backing for stainless

Another concern of mine would be how safe this would be to use on a piece for the food industry. How hard is it to clean off when you're done?

I think I'm gonna move forward with making some sort of flange doohickey.

This is a piece of 1" square tubing, welded up the ends, gonna weld on that fitting that was formerly a double female, black anodized aluminum fitting for a nitrous system in a drag car. Cut it half, sanded the finish off, then gonna screw in that valve. Hope it works.

[ryanjones2150]

Here it is. I stretched out a stainless steel Brillo pad and stuffed it in there as a diffuser too.

It's 10" long so I can clamp it in place on these long outside corner welds and then move it quickly from side to side as I walk around this thing.

[ryanjones2150]

You guys are probably tired of my posts by now!

Here is a test. This is the same material as the job I'm working on, 20ga stainless, using a 3/32 thoriated tungsten and 1/16" 308 filler. The one on the right is with using copper plate as a backer and the one on the left is using my new aluminum back purge thing flowing 15cfh. I think it'll work.

[elvis]

So what are you making?