Welding Tips and Tricks

I just went by the sheet metal shop and they gave me a bunch of stainless scraps to practice on. I was just wondering what types of joints are most common with stainless sheet so that I will know where to focus my practice. I do not have a dual flow regulator so my welds will not be purged. Any pointers for welding without purge would be greatly appreciated.
I went this morning and took a fabrication test for a welding shop and aced it but the owner isn't quite sure whether he's ready to hire someone at this point. So my search continues. I keep seeing internet ads for stainless tig welders for kitchen service equipment. That's why I went and got this scrap. I would be very surprised to learn that a production facility like that does any purging of welds but I don't know anything for certain.
I know that a lot of you guys do this stuff day in and day out so any insights you have for me are very much needed.
Thanks in advance.
Edit:
I don't know what grade(s) of stainless that I have but I believe that I was given 20, 18 & 16 gauge scrap. I only have 308 and 309L (1/16") wire in my kit. Should I get 312 wire or some other alloy for this practice? Should I get smaller filler as well?

My most common joints are round and beveled. For that light stuff a fillet isn't a challenge at all, mix/match thickness on some butt and lap welds. Your filler is fine for what you will be doing.

Thank you very much sir.

Alot of square butt joints with filler and without. Also outside corner joints without filler if fitup is tight. Practice speed tacking and fitup. Use aluminum angles and flats for backers and you won't need to purge. Pony clamps are handy for this.

INTENTIONAL THREAD HIJACK!!!

I was screwin around with some 18ga. 304 tube in preparation for a possible upcoming job.I don't tig very often.

Maybe some 316 filler in 1/16 or 3/32.

I have plenty of pony clamps and aluminum tubing to back with.
316 I'll have to get......
That's some damn good looking welding for someone who doesn't tig often.
Thanks guys.

Yer it is good welding for someone who doesn't tig often. Maybe I should screw im over by posting one of my mig welds.

Coldman wrote:Yer it is good welding for someone who doesn't tig often. Maybe I should screw im over by posting one of my mig welds.

Bring it on man!!

Just did the magnet test on all the scrap I was given and it appears to be 304 or 316. It also appears to be about as soft as pure aluminum (didn't expect that). The 20 gauge is smaller than my filler wire so I guess I'll try autogenous welds with that stuff. Gotta wait for the thunder storms to pass and for the power to be restored before I get to try welding it.

You'll be okay using filler. The metal I welded was 18ga and I used 1/16" on it. Sorry I hi-jacked you but I was going to make a post of the same subject until I saw yours Post up some pics so maybe I won't feel so bad about my welds

jeff
your welds are never bad. only good and better
craig

motox wrote:jeff
your welds are never bad. only good and better
craig

I appreciate that craig. I strive for perfection but I am my own worst critic and tend to be hard on myself. No matter how good they look, I am never really happy with them. I think I need psychological intervention

I'll post photos once the storms pass. Don't wanna have a surge kill my machine. Power has gone out three times so far.
I'm guessing that most welds on kitchen equipment are no more than 1"- 2" ?
Are there any visual clues from under the hood that tell you when you're cooking stainless or do you just set amperage according to base thickness and fly?
Didn't realize that the post had been hijacked but I don't even care if it helps me or someone else. Heck, I don't even care when they turn into chit-chat sessions.

I couldn't tell you if there are any visual clues but I just know not to throw the heat into thin SS as it always cooks it when you stay in too long. I set my amps for thickness and add a few more so I can get more horsepower if I need it.

It looks like I only have (roughly) .046 & .062 so I'm gonna see how it goes with 30 & 40 amps. I kinda figure that i may need just a touch more since I'm gonna be using aluminium backing and the rod is gonna chill it even more but I plan to start slow to see how this stuff welds and try to get a feel for it from there. In the past I usually dumped too much heat in when learning.

Dreaded Chinese self criticism drill:

This is my only crappy weld tonight. I had to cut with a die grinder because I can't see outside to use the chop saw.
.062 outside corner, 20 cfh, 7 seconds post flow, 3/32 - 2%lanthanated, #7 cup with gas lense, 1/16 - 308 wire. I couldn't even tack it at 40 amps due to the quench of the .250 aluminum backing tube. That's why it's peeled back on the left corner. I cranked it up to 60 amps and the wire wanted to stick in the puddle as it added additional quench. Very crappy looking weld but it did penetrate most of the back side and I believe that happened due to the filler sticking in the puddle and pulling the pieces slightly away from the backing tube. Pushing wire into the puddle would push the work pieces back up against the tubing. Rinse and repeat. I'll try using .125 tubing tomorrow because it was cool enough to pick up with my bare hands after five seconds. Never had anything cool so quickly without dunking it in a bucket of water. No sugaring is about the only good thing that I can say.
That's roughly a 2" run and it took about 15 seconds which seemed ridiculously slow to me. I was shooting for about two dabs per second but the wire sticking slowed it down to about 1.5 per second. I just couldn't move as fast as I wanted to.
I really should have twisted the backing tube so as to be able to weld flat. As it were, I had to weld in more of a horizontal position with the torch pointed down.....hence the sagging weld and undercut on the top. Didn't even realize this until I saw my bastard child out from under the hood. Cold, sticky puddle caused uneven dipping. I was too focused on fighting with the stickiness to notice much else. I thought it would eventually stop sticking but I realized after it was all over that it was never going to get any better because this stuff isn't very thermally conductive. That was one of those "Ah Ha!" moments but I will probably have to repeat it several more times before it sinks in.
It seems like there is a very fine line between hot enough to weld and overheated with this stuff.
Hopefully you guys will have lots of suggestions for what else I can expect, how to go about getting it done properly and pitfalls to avoid. I really think the biggest problem on this run was lack of heat.
Fire away and don't hold back.
FIDO!

How do your welds look if you run beads on the flat ie: straight beads not fillet or corner welds? And have you tried using a bigger cup?

Flo

The largest cup I own is #8. I never use them because they make it harder to see. Everything looks fine normally.

jeff
beer therapy.
craig

RamboBaby wrote:The largest cup I own is #8. I never use them because they make it harder to see. Everything looks fine normally.

Outside corner welds are a bitch on thin material, especially SS because the metal doesn't conduct heat away from the weld, Even though you used a chill bar, the heat can't get out of the way fast enough. Thats when you need to ease up on the pedal. Thicker material is easier because you kinda of use the gap as a trough to hold your filler but with thin stuff, its harder to control. I do see a couple of really pretty filets you did there.

:

motox wrote:jeff
beer therapy.
craig

Trust me, if alcohol therapy has any real effect, I am the most well adjusted drunk on the planet....except for them Aussies
Maybe if I wasn't shaking so bad from the hangover, my tig welds would look better

exnailpounder wrote:

RamboBaby wrote:The largest cup I own is #8. I never use them because they make it harder to see. Everything looks fine normally.

Outside corner welds are a bitch on thin material, especially SS because the metal doesn't conduct heat away from the weld, Even though you used a chill bar, the heat can't get out of the way fast enough. Thats when you need to ease up on the pedal. Thicker material is easier because you kinda of use the gap as a trough to hold your filler but with thin stuff, its harder to control. I do see a couple of really pretty filets you did there.

So a pulsing technique would probably work better? I'll give it a few more amps and try that. I probably should have wiped it down with acetone since the die grinder spit oil (transmission fluid) all over it. I only wiped it with a dry paper towel.
This was an absolute mess and I felt almost as if I didn't even have a clue how to tig weld. It's definitely a unique experience.

Coldman wrote:Also outside corner joints without filler if fitup is tight.

Ok, that's where I went wrong on this. Fitup was easy since the metal was originally cut in a shear. I'll try this one next because the filler was definitely giving me fits. I just have to wait for these folks to wake up before I start running the chop saw. It's located less than 50 yards from the house and I don't wanna piss off anyone with that kinda wake up call.

Pulse would help but I never use it. I pulse with the pedal instead. I am also a firm believer in short welds on SS because of its poor conductivity. I don't know how to explain it but I will try. Stainless sucks for conductivity. Aluminum excels at it. So you are expecting the chill bar to draw out all of the heat from the SS. It draws out some but the SS doesn't give up its heat fast enough so it builds up and the metal overheats and your puddle gets unstable and other goodies happen, A similar scenario would be when your welding on aluminum and your getting closer to the end of the piece and you see the puddle flatten out because the heat has no where to go so it builds up. If you don't back off the gas, you will blow it out. Normally you can do long runs on AL without too much trouble but getting to the end of a piece is where you can get into trouble. Thin stainless is a pain because the heat builds so fast. One second you are welding fine and the next you have a unstable puddle that turns gray and basically riuns the integrity of the metal. I don't know if that explains it but I tried Get in and get out on SS. If you want long, pretty runs with no starts and stops, use MS. You can cook MS too. The key is using the proper amperage, travel speed etc...