Tig welding ?'s stainless/aluminum
 

Hey i just started tig welding last week and it's going well. I've had numerous people tell me different things about welding alum and stainless tubing.

What method would you suggest for welding alum?
My instructor is teaching to use pure tungsten, then build a ball of bronze on the end using reverse polarity. Then go ahead and weld alum using AC current. Are there any other ways besides that and is pure tungsten required or just preffered?

I've also had two different opinions thrown at me about welding stainless. One that stainless is the easiest thing to weld and another saying that stainless is very difficult and tubing is ridiculously difficult because its so easy to burn through. How much current do you usually use when welding stainless tubing and what other tips do you have for stainless?

Also, do you know of any good online resources i could browse through besides Miller's education pages to learn some more? Maybe a fabrication forum. So far welding mild has been going just fine and I'm liking tig alot, just have alot of questions that can't be answered at night. :) Thanks

As for welding aluminum, I haven't done nearly as much of that so I can only say good luck. I usually use neg. polarity and pure tungsten. Stainless is my favorite to weld as once you get it dialed in looks very pretty. 16g tubing is a bit tricky until you get use to how much heat and such. Thick stainless is not as bad, and I prefer it.

Everything you want to know and more, including converting a stick welder to TIG..

http://www.hobartwelders.com/mboard/

I agree with thebandit. Welding two pieces of brand new freshly machined aluminum that's the same thickness is not hard. But say...welding new thin pipes to an old corroded starion intercooler is very much a pain in the ass. Not fun at all. Welding to cast aluminum (valve cover, water neck) takes patience too. As far as settings, I set it to A/C; my lincoln welder has an automatic setting for balance control for welding aluminum and works pretty well. 100% tungsten electrode.

I think stainless and mild steels weld very similary; i.e. very easy. I love it. For thin walled stuff like I use (Vibrant J-bends) I'm around 40amps max. I probably weld around 25 amps actually. If there is no gap and the strength of the weld isn't critical, you won't need filler rod either. I grind a very tiny sharp tip to the electrode. OH, and I use argon to purge the inside or else you'll get sugaring.

For thicker metals like sch. 40 weld ell's, i think I use a current around 125amps or so (whatever is recommended in my slide rule thing), thicker electrode with a rounded tip, thicker filler rod.

Depending on the thickness of the two items you are welding, it may be easier to step down in material thickness. For example, welding a .060 thick downpipe to a 1/2 flange takes some skill. If you have the room, it is easier to step down from 1/2 to 1/8 then to the .060 pipe.

Clamp down flanges when you weld, they like to warp if you aren't careful.

Appreciate it guys, it's always nice to get some real world info from people who do this often.

I always use 2% thoriated (red band) tungsten on aluminum, even though you technically arn't suppose to. I find it easier to maintain a good bead. A/C with a balanced wave usually gives me the best results.

Trick to aluminum is to plow the filler in, it takes a lot of heat sink to keep the puddle from becoming a hole.

My best learning experience was trying to lay a bead around the lip of a pipe, standing on end. It doesn't waste a lot of material, and if it gets messed up you can just cut of a bit of the pipe and start over fresh. After an hour of that, you can weld anything!

bottom of an aluminum can works too.

if you're real good you can try the side.

When I was learning I found it a big help welding the outer part of angles (think the top of the letter A). You can see exactly what is happening and its very easy to control where the arc is going. I practiced running a bead without filler first then moved on to making structurally sound welds. After I had that down I moved on to the inner angle and had no problem with back cutting (or whatever its called).

Yeah my old welding teach in highschool used to tell me about welding a aluminum pop can together. Then my current teacher told me about welding foil to a rod. Another about welding two razor blades together, pretty cool stuff.

I've always used thoriated on AL too... not supposed to but the Lincoln seems to compensate. Stainless steel is a breeze.... aluminum likes a lot of heat and in general is more of a PITA than steel.

Mark

I envy everyone in this thread.

Me too, but only because I cant afford a TIG :(

Once my Garage is built next fall the first thing I'll be buying will be a MIG welder. I'm so excited I could pee.

+1. A good one is painfully expensive. I'm not buying one until I can afford something decent. (And learn how to actually use it :gay: )



That sounds great. I like the pee part. I built my garage last year, the MIG is next on my list. The only downfall is I only have 110 available.

Junk, save for a TIG. Unless you plan on welding just little stuff.

What specifically can't you weld with a MIG welder?

What? You are totally talking out of your ass. MIG is going to be the easiest to learn and the most versitile. What kind of welder do you have again?

Jay

the only thing that I know of that tig can do that mig can is exotic metals like titamium and magnesium, etc... Some of the newer high end migs that are coming out from miller are actually just as good as a tig machine and just as pretty. The welding industry is pumping out new tech as fast as the computer industry.

I rarely use my MIG since I got the tig. Only on misc. bs stuff and for tacking. It wouldn't be bad for most, but if I could only have one it would be a TIG.
-Michael-