tig stainless

[shoprat]

i just recently took a pre employment weld test on 1/16 stainless for an outfit that does parts for small planes exhaust parts mostly i did a butt a lap and a tee.i didnt do very good and dont think ill get called but any way the guy said i welded too hot,i had about an 1/8 wide bead but it had a haz area about 3/4 wide to an 1'' so i tried some more when i got home and cant get it any smaller than that,it comes right off with a wire brush though.any ideas? thanks shoprat

[tigman]

what size filler rod are you using and could you post a pic.I'm no expert on tigging stainless as my total hrs might add up to 40,but I have been told that the weld should have a reddish goldish colour to it.I would guess that if you were told you were welding to hot that the weld has a dark burnt look to it.I don't know how to keep the blackish discolouration from forming alongside the weld.I hope someone here steps up to the plate as someone has to have alot of SS experience.Scott

[aircraft]

Well without wactching I'll give some pointers.

Make sure it's clean, pure argon back gas 100% coverage both on obverse and reverse side. Never ever weave from toe to toe use only stringer beads. If you are used to steel use 20% less heat than your used to. If your too hot, reduce heat and go slower what I mean is don't try to reduce heat by moving faster you can't rush SS. Be sure your filler rod never leaves your gas coverage. The cup we use is 1" even though we use .040 or 1/16 tungsten to help with coverage and filler rod coverage.

You will know if your on target if the whole weld looks like a new nickle no purple allowed....anywhere.

[shoprat]

tig stainless

thanks you guys i thought maybe i needed more gas coverage but i went to my supplyer to get a gas lense and they were out and he said i couldnt use a bigger cup for my torch its a water cooled diamond back torch w/#7 cup.the one i tested on was almost an 1'' but they didnt back gas(at least not for the test) my welds at home were purple so i will try less heat and more speed. thanks again for the help

[shoprat]

oops

i meant move slower and less heat sorry!!

[George]

hello,,I am new to the forum but my everday occupation is tig welding light gauge stainless.when you"re welding the "t" joint or fillet concentrate your heat on the bottom part until the puddle washes up at that point you will have the correct heat temp.using an .045 tig wire your welder should be set around 75.

good luck,,,,,George

[tigman]

Hi George,what guage and grade material do you work with.
Do you have any pointers for start stops as I always have trouble with this,they end up a little lumpy.Thanks Scott.

[Guest]

We use this torch setup through out the plant. It offers the best gas coverage of any other kind. It's kinda clunky at first, but you get used to it, and there's has never been a situation couldn't use it in. In this shot, I'm using a 3/32" 2% thoriated tungsten. 1/16" would have been a better choice, but I like to challenge myself.

I'm doing a lap weld on .040" 321 stainless. Under the plate is a block of porous bronze for purging.

[Guest]

Here is a sample

[Guest]

And another...it's blue because I go fast. To eliminate the blue chill bars on either side of the weld would do it.

[Guest]

Here's one where I went slower...but for me, it is more difficult to keep the ripples even. The rythm has to be such that you don't think about it...it comes natural and steady. Practice, practice, practice! Where have I heard that before??

[aircraft]

Originally posted by Rocky D
And another...it's blue because I go fast. To eliminate the blue chill bars on either side of the weld would do it.

Or gas coverage.

[Charles Sand]

Great Pics, RockyD

Keep 'em coming!
Definately "save as" pics.

[rpm1]

Rocky D,

Where would one find a chunk of porous bronze that size for backpurging, or is that a commercial item?

Thanks
Ron

[Guest]

Originally posted by rpm1
Rocky D,

Where would one find a chunk of porous bronze that size for backpurging, or is that a commercial item?

Thanks
Ron

I wish I could help you there, you see we had a whole bunch of them 6 x 8 inches. I don't where they came from, only that they are used for filters of some kind. There certainly must be a manufacturer of it somewhere.

That's a good assignment for the computer gurus out there!