Welding aluminum with a MIG

smithmiller6 · Post by **smithmiller6** » Sun Jun 21, 2009 11:10 pm

Hi
I have a miller 185 mig,is it possible to weld alum?
If not what da ya suggest without purchasing a tig.

Thanks

aircooledtechguy · Post by **aircooledtechguy** » Mon Jun 22, 2009 7:55 am

You can weld aluminum with that. You need the alum welding wire and a bottle of 100% argon NOT the 75%/25% argon/CO2 that is used for steel MIG.

You'll also need a small pile of scrap to practice on to get your settings and technique down pat before you go burning holes in your project

Welding aluminum can be a challenge.

rayjay · Post by **rayjay** » Mon Jun 22, 2009 12:49 pm

You really need a spool gun and for best results you should preheat the parts with a torch.

fusername · Post by **fusername** » Mon Jun 22, 2009 2:32 pm

any other tips/reccomendations? would really like to add aluminum to my list of things I can weld. For example, hypothetically speaking, if I were to drop my case and break an ear off the bellhousing, and would rather have it back on, how would one prep and service such a thing, and what wire/mix is best?

aircooledtechguy · Post by **aircooledtechguy** » Mon Jun 22, 2009 5:01 pm

For kicks, a while back, I used a spool gun to weld some alum test plates. . . I find it much easier to weld aluminum with a TIG welder. TIG gives you infinite on-the-fly control of the process and IMHO yields better, more consistent results.

Bugfuel · Post by **Bugfuel** » Mon Jun 22, 2009 5:03 pm

the stock engine case is mostly Magnesium, not aluminum.
It can be welded but I wouldnät try a MIG. Tig is the way to go, and even then you need to crank the Argon flow sky high.

on some MIGS you can set the gas flow to stay on a while after you release the trigger, on my professional MIG welder it was adjustable. It cools down teh weld after you stop adding to it. if you donät have this feature, you will likely have problems. Some people extend aftercooling with shop air. Not perfect but it helps.

bugdust69 · Post by **bugdust69** » Fri Jul 24, 2009 7:17 pm

rayjay wrote:You really need a spool gun and for best results you should preheat the parts with a torch.

I strongly disagree on both counts. Spool guns are a PITA to use IMO. They are bulky and not balanced. I've used them many times but I would prefer to change out the liner and run the filler through the whip for a MIG. Tig is even better but I don't have one. I have access to one but it's easier to just switch out a bottle and liner and a roll of wire than to load up a project and take it somewhere. You may preheat aluminum when you weld it but I've never done it or heard of anyone that has. The only time I ever heated aluminum was while welding a cast intake. I v-grooved the crack, preheated it to ~400* (used a temp stick to monitor) and TIG-welded it. I don't remember what filler I used (been 15 yrs ago).

dorkie · Post by **dorkie** » Sat Jul 25, 2009 3:35 pm

bugdust69 wrote:
rayjay wrote:You really need a spool gun and for best results you should preheat the parts with a torch.
You may preheat aluminum when you weld it but I've never done it or heard of anyone that has. The only time I ever heated aluminum was while welding a cast intake. I v-grooved the crack, preheated it to ~400* (used a temp stick to monitor) and TIG-welded it.

...

Bugfuel · Post by **Bugfuel** » Sat Jul 25, 2009 4:11 pm

preheating and controlled, slow cooling is recommended when welding cast parts that may warp if heat is applied to just one limited area, like intake manifolds, heads, etc..
Preheat is not so critical if you are working on aluminum stock or sheet.
As always heat may warp large flat sheetmetal parts.

AtvMxRider · Post by **AtvMxRider** » Sat Jul 25, 2009 6:10 pm

bugdust69 wrote:
rayjay wrote:You really need a spool gun and for best results you should preheat the parts with a torch.
I strongly disagree on both counts. Spool guns are a PITA to use IMO. They are bulky and not balanced. I've used them many times but I would prefer to change out the liner and run the filler through the whip for a MIG. Tig is even better but I don't have one. I have access to one but it's easier to just switch out a bottle and liner and a roll of wire than to load up a project and take it somewhere. You may preheat aluminum when you weld it but I've never done it or heard of anyone that has. The only time I ever heated aluminum was while welding a cast intake. I v-grooved the crack, preheated it to ~400* (used a temp stick to monitor) and TIG-welded it. I don't remember what filler I used (been 15 yrs ago).

I weld aluminum with a spool gun on an almost daily basis. You WILL get a much better weld if you pre heat it with a torch. Don't melt it but get it hot.

Post by **Piledriver** » Sun Jul 26, 2009 6:01 pm

Bugfuel wrote:the stock engine case is mostly Magnesium, not aluminum.

Depends on which cases... T4 and WBX cases are aluminum, 6061 IIRC.

A good preheat on a big part is not just a good idea... I won't even try aluminum at work with the big Miller TIG, but I suck anyway.

fusername · Post by **fusername** » Sun Jul 26, 2009 7:54 pm

curious where you get that fact from, t4 cases being 6061. I have a junk case and want to do some backyard casting, and i dont know how well it melts, but i know how well 6061 machines and is quite durable

Post by **Piledriver** » Sun Jul 26, 2009 8:07 pm

6061T6...That's what my memory requests are returning, heads being 356T6. (Why I said "IIRC")

Fact? No idea, Google is your friend.

NEBUGGERNATOR · Post by **NEBUGGERNATOR** » Wed Sep 09, 2009 7:00 pm

It is hard to "push" aluminum wire through a mig welding lead that is long. The dreaded "bird's nest" will occur if the line kinks to any degree. That is why the spool guns are popular, because they "pull" the aluminum wire. Yes you can get a large roll of aluminum to work in the traditional mig style lead ir everything is working good, a short lead help greatly. The best type of aluminum mig is the type that pulls the wire through the typical long lead of the standard mig [pulls the wire throgh it using a small electric motor up near the welding tip] .The one I used to use was called a Miller "cobramatic", it had a head that looks kinda like a cobras head. Let me tell you, you can weld aluminum with this machine as fast as you feel brave enough to do so. [or how steady your hand is].
Another option is gas welding believe it or not! (check out the "Cobra gas welding torch" AKA: Henrob torch.) Video demonstrates gas welding aluminum.
TIG is nice too but also expensive and slow. Sometimes it heats up the metal too fast, causing it to pull and warp, especially on the thin stuff. The MIG process has less of a tendency to do this because it goes so fast.
I think the spool gun is a good alternative considering the price and the adaptability. AS stated, the limiting factor is welding in tight quarters. Oh well, just my 2 cents worth. I'm a "too long poster" I guess.
[I've read that the type IV cases are easily welded with proper tech]

Jogyver · Post by **Jogyver** » Fri Sep 25, 2009 7:30 am

Here's a great link to follow
http://www.lincolnelectric.com/knowledg ... actmig.asp