TIG welding question

[tminer]

Should it be OK to TIG a stainless O2 bung onto a stainless THDP? The fabricator that I found expressed some concern about the thickness of the pipe (he hasn't seen either piece yet).

The bung is from HR P&S and is pretty stout.

Thanks,
Tom

 

[KendallF]

No big deal..I've done a couple. Just get a good welder.

 

[zam70]

yeP, A GOOD WELDER SHOULD BE ABLE TO TIG THAT BABY TO ALUMINUM FOIL!

It's all about heat control.

 

[tminer]

Thanks. If he hesitates I'll run!

Tom

 

[Dr. Freeze]

3/32" tungsten, about 70 on amperage with the argon at 18... Put more heat on the bung (it's a fillet weld really) than the d.p... ANY competent TIG welder should be able to do this without even thinking about it. Hell, a MIG with stainless wire would be simple too...But not as attractive.
-Jeb

 

[KendallF]

Speaking of welding ridiculously thin stuff...

teensy weensy welded tubes

Local guy wanted to use AN lines for his oil cooler and still use the radiator's cooler..couldn't find the fitting. So I welded these up from a chopped up set of old oil cooler lines. Had to use MIG wire for filler.

 

[tminer]

BTW, what is a reasonable charge for this job?

How can I prep the pipe? Create a flat spot and drill a hole slightly smaller than the bung is what I figure, but I really do not have a clue and was going to ask the guy when I call him before bringing over the pipe.

Thanks again,
Tom

 

[Ormand]

Prep for the pipe..

IMO, it's better to slowly and carefully grind on the back of the bung to match it to the curve of the DP, rather than to "flat spot" the DP. Shouldn't take more than a few minutes with a die grinder to get a reasonably good match, and it will allow a good weld, without disrupting the flow. You can drill the hole either before or after the bung is on, but if it's a threaded bung, before might be better.

 

[TurboDiverArt]

Originally posted by Dr. Freeze
3/32" tungsten, about 70 on amperage with the argon at 18... Put more heat on the bung (it's a fillet weld really) than the d.p... ANY competent TIG welder should be able to do this without even thinking about it. Hell, a MIG with stainless wire would be simple too...But not as attractive.
-Jeb

I've done this twice to the same pipe! Like mentioned above, more heat to the bung or you will burn through the DP but you need to be careful. The first time I used about 80 amps and let the bung heat up. I ended up distorting the bung and had to cut it off and weld on a new one (thanks Paul from HR Parts-N-Stuff for shipping out a new one ASAP!)! You need to make sure the weld seals the mating surface but your not hanging 1000 lbs off it so don't go crazy.

I suggest slightly denting the DP to make a flat surface. Since the pipe is round and the bung is flat you'll have gaps on the sides. I guess another option is to shave down the bung a little to have it contour to the pipe. It's just easier if there are no gaps.

Hope this helps!