MIG on Alu thoughts.

[Dr. Rob]

For some darn reason I just haven't gotten around to trying this. Have had the MIG with reversible polarity for years, but have always relied on TIG anyways. So what the heck, right? Might as well spark it up. Anything to keep in mind? Clean joint, stainless steel brush? As per the usual? Pure Argon okay?

[cliff69]

Unless you have a spool gun, it is really hard to feed aluminum wire.

[alcova]

Yes pure Argon is ok, it's recomended... least oon my machine - Miller 210

Walt

[JRouche]

A teflon liner and different rollers. Like suggested a spool gun works real nice. JRouche

[Tinkerer]

I've pushed pounds of .30 Alum wire. 100% Argon and plastic line are a must. You'll have to play the feed roller presure to get it right... once set you'll be fine.

Tim

[Thrud]

Teflon liner - best used with a Miller Push/Pull Aluminum MIG machine - they really work well. I prefer TIG on Aluminum - always looks good - unlike the rat **** you can get with the Aluminum MIG especially with just the spool gun or regular feed - not pretty at all.

[Doc Nickel]

I used to work in a boat shop- they made aluminum hulls from 12' skiffs upt to 40+ foot stern-picker fishing boats.

They had two or three "Cobramatic" wirefeed MIGs, the ones with the fat gun with it's own wirefeed drive. These guys could lay down some fairly impressive beads with these guns, and quite quickly too.

They also had at least one standard TIG and a heavily-modified wirefeed TIG-gun. These were used for the projects that needed better weld control.

Now, in the years since, I have seen very few people run an aluminum MIG nearly as well. Most, in fact, suck- it's probably not the weldor, I believe it's the fact they're trying to use aluminum wire in a push-only stinger (that and in a lot of cases trying to use a 110V machine.)

As the others said- teflon liner is a must. Needs to be a heavier machine, a 110V won't cut it except on the lightest materials. Pure Argon; although Helium is supposed to give a hotter arc with the TIG, I don't know if that holds true with the MIG as well. Keep the stinger cable as straight as possible, and keep bends to the largest conveninent radius. You'll need serrated or roughened rollers to get a grip on thew wire. Reduce spool tension to near-zero. (Just enough to prevent a snarl.)

And cleanliness is even more important than with a TIG. Scotchbrite, stainless wire brush, chemical etch and/or acetone- and like the book says, don't clean today and weld tomorrow; clean today and weld right now!.

Doc.

[gunsmith]

I used the teflon liner up until about a month ago. Mine is a push and uses a rubber drive wheel and a teflon liner when I switch to alum. It has always been a bit of a pain but usually only when I was putting too many bends in the cable. I got pretty good results if I kept my hose as streight as possible. Last month I forgot to change to the teflon liner. What a difference. I now have the smoothest feed I have ever had using the liner for steel wire. I don't no how long this will last but what a difference. Bends in the line seem to have no affect either. I will never go back to teflon again if I don't have to.

[wierdscience]

Largest tip possible,like an .045 or .059,put a slight bend in it to make contact.Use the teflon liner on hopefully a short whip(8 foot is okay,6 is better) and use small wire .023.

It helps dramaticly to preheat,sometimes just setting the part out in the sun does the trick,heat gun also helps.Don't use a propane torch,water vapor will deposit on the surface and make it a beach to weld.

Keep the nozzle moving,your moving too slow when you hear it pop and sizzle.It should sound like an air leak when welding.

[mattc]

I got a spool gun and controller for my miller 175 but I have only used it once so I cant give a fair assement as it was my first attempt a welding Alu and I think I was most of my problem


Matt in AK