Hello all, I tried searching with "aluminum" and "welding" but the only reference was to welding stainless steel.

I need to repair a cast aluminum housing and I have a 120 volt mig welder with 75/25 Argon/CO2 gas.

The repair is to fill in an 1/8" crevasse to stop leaking.

Can I do a leakproof weld with my equipment? The repair will be hidden once finished.

Thanks! And happy new year!

 

Im no expert by far, but i dont think you can weld that with your welder.

I think you need a Tig welder, but i am not sure.


Anyone else??

 

You can weld aluminum with a MIG. You just need the right mix of shielding gas.

I know if you use too small a wire diameter you need a spool gun because the AL wire is so soft it won't feed thru the MIG gun properly.

 

Technically, you can weld aluminum with an oxy/acetylene torch set, but it's about as tricky as trying to push a piece of spaghetti through a chunk of Jello.

 

cool, learn something everyday

 

Your best bet is to go to your local welding store and talk to them.
Tell them what you have and they should be able to tell you if you can use the stuff you have,and if so what you will need.
Just a question, is the welder you have somewhat of a name brand or is it like a sears or wal-mart special?
If it is a generic, it may be tough to find the right stuff to do the job with.

 

haha, that is so true

 

actually aluminum isn't hard to weld with a oxy actelene torch if it's a thick piece, 1/4" or more. tig or GTAW would be my prefered method. aluminum welds very nicely with the 110v migs, or more correctly GMAW, you'd need a tefelon liner and maybe a tip with a larger hole than you would for steel, you'd also need pure argon and not c25 like you been using.

 

Then before you weld it, practice on a few scrap pieces first, I used to repair Featherlite trailers everyday, we used a spool gun, but aluminum is aluminum, it welds VERY quickly, I'd say you need to drag/push the bead about twice the speed as you would steel. My guy that worked at our welding supply store, said you did'nt need to run the liner in the hose, that was for my little Miller 130. Never tried it, but would be interested in your results.
Clean surface with Stainless steel brush, 100% argon, gas, practice on scrap and you'll be all right.

 

Oh, SURE! (Show-off) Just because you're an experienced welder, and I'm a hack. I'll bet you practice on empty pop cans with a rosebud tip just to **** off the neighbors.

Ususally, VADER + ALUMINUM + WELDER = SCRAP....

(I was hoping you'd chime in on this thread.)

 

Thanks for the info. I will hit a welding supply and probably rent a 100% Argon tank and ask which wire to use.

And practice, practice, practice before I do the real thing.

Should I preheat the working area with a propane torch or is that an act in futility?

The repair is circular with a diameter of 7" or 22" of circumference. The advise I'm getting is to weld a spot (maybe 1/2" to an 1") then jump a 1/4 of the circle and weld another spot and repeat.

The repair has to not distort the housing.

 

i prefer 5356 wire, but i doubt you'll know the differance with any filler they give you. you want the metal clean and the surface ground or sanded to remove the layer of oxide that forms on aluminum. it takes about 400*F more to melt it than it does the metal under it, one reason lot of people have trouble welding aluminum.

vader i might be able to stumble along and do pretty good with most welding jobs, but i never have been able to master "walking the cup" when welding pipe with tig, sure wish i could learn it.

 

man i tried welding some 16 gau. aluminum with a gas torch and it was like impossible, you can't (well at least i couldn't) see the puddle and every time i just blow though.... now mig is a different story i tried it and was quite easy.. just gotta move quick.. i saw some dude weld the edges of 2 razor blades together with a tig and that was crazy

 

Ede,

I'm a little surprised. I think a TIG with HF start is the easiest, cleanest, best way to weld. If I were doing aluminum often (like John Millican), that's all I'd have. With a little dedicated practice and a good copper plate, I think I could stick two pop cans eventually - not that I'm any good, but it's that easy to use. It is slower than a MIG for sure, but it is far more controllable and produces a very clean finish. Then again, I don't weld anything that really matters much, either. ASME/PED stuff is out of my league. And all the automated production welders I've worked on are MIG, so that says something. (Time=Money)