MIG Welding Aluminum: Tips, Tricks, Pics

My search turned up plenty about TIG welding aluminum, but I don't have a TIG (wish I did). My MIG will handle probably only very thin aluminum, since it's only a 110V unit. I've done plenty of steel work, but I'd like to try aluminum in the future and was hoping you all could offer some advice, share your successes and failures, and post some pics of your work if possible.

From what I've found on the web, the basics of MIG welding aluminum include the following:

100% Argon shielding gas
Use 0.035", 4043 wire to start (for beginners)
Purchase an aluminum feed kit, if your MIG is not already equipped (includes special feed rollers, non-metallic liner, etc.)
Switch machine to electrode positive
Use a "push" technique
Pre-heat the weld area
Use a 20-30 cubic foot per hour flow rate for the shielding gas

Anything critical that I'm missing?

Thanks

 

You don't necessarily NEED one of those high dollar spool guns to weld aluminum with your MIG. Make sure your wire liner is clean, use some liner powder to keep it smooth. Make sure not to bend your lead wire too tight or the aluminum wire will bind up and birdnest inside your machine.

We do aluminum fabrication at work all day long. We have big Miller welders with spool guns, but we recently got a smaller Miller 110volt MIG to get into tight places on thin aluminum. We bought the spool gun, but didn't like it on that particular machine, so we run through the normal lead wire, as if we were welding steel. 100% Argon, and the same type of Aluminum wire that you can buy at Lowe's.

It works well, but it the machine is running full blast and is only capable of welding up to about 1/16" thick, in small bursts or short beads. 1/8" if you make a double pass. No preheating unless you're doing something thicker than 1/8". Most of our work is tack welding, and structural beads, and a fast production rate, so we do not use TIG welders.

I suggest that if you're willing to shell out the coin for a spool gun, you might as well sell your 110V welder, and buy a nice 220V and a spool gun, so that you can weld thicker material.

 

I'm not planning on buying the spool gun for my machine as it is too costly (it's a Snap-on), I was thinking of just buying the wire and the gas and giving it a go. Thanks for the advice, I hear ya on not being able to weld thick material. Looks like I'll be limited to aluminum sheet for a while.

 

I production welded aluminum light poles for 3 years, we pushed the .045 wire through a plastic liner and ran a .055 tip... That shop ran 24-7 with 6 welding stations and we never used a spool gun. Keep the cord from the gun to the machine straight to allow the wire to run smooth if the cord is wound tight it will cause drag in the liner and the wire will push harder causing a birds nest... Welding aluminum is fun with a wire welder... It's gonna' take some time to get the setting right so take your time.

 

I've been advised against running aluminum wire through the same liner as steel. I was told the copper clad from the steel wire will contaminate the weld.
As compared to welding steel, aluminum MIG welding will take learning and practice. If you have access to a TIG, I think you should take advantage of it.
To check preheat temperature, buy "temp sticks" from your welding supplier. They look like a crayon and you can buy for different melting temps.

 

I don't know what 110 welder you have But this is what Lincoln had to say about theirs.

While there are many different models of Lincoln compact wire feeder welders
on the market, most of them are represented by one of four different models as
follow:
SP-135T – 115V input with tapped output voltage control
SP-135 Plus – 115V input with infinitely variable output voltage control
SP-175T – 230V input with tapped output voltage control
SP-175 Plus – 230V input with infinitely variable output voltage control
The continuously variable voltage welders will weld aluminum slightly better than
the tapped models because you have better voltage control. They also have a
more robust wire drive system than the tapped welders. However, they are more
expensive than the equivalent tapped welder.
The welders running from a 230V supply will put out more current and will be
capable of welding a wider range of thicknesses than those running from 115V.
Lincoln rates the 115V welders as being capable of welding 0.030” to 1/8” thick
aluminum. The 230V welders are rated as being capable of welding 0.030” to
1/4” thick aluminum. However, welder skill must also be taken into account. A
very skilled MIG welder will be able to weld 0.030” material. Most people will
not, so that it may be best to consider 1/16” thickness as a practical minimum
thickness.​

Filler Wire​

All of these welders are best used only with .035” 4043 alloy aluminum wire. Do
not use 5356 wire or wires of .030” diameter. They will not work well.​

Shielding Gas​

Only pure argon or argon/helium mixtures are suitable for MIG welding
aluminum. Argon/helium mixtures are really appropriate for heavier thicknesses,​

so, in all cases, argon is the correct shielding gas.

Just a idea as some of their smaller 110 can handle ? I have a small
sp 135 plus and I like it. But i am upgrading here soon to a
Power MIG 180C 208-230/1/60 And may very well ad the Spool guy at the same time.

 

I like the idea of NO spool because you can get into smaller places and its lighter ,

any other tips?
does the alloy of the aluminum you are welding matter ?
do you clean the aluminum with a stainless brush first or will any brush work ?
what about old original aluminum welding to a new aluminum patch ?

Pre heat the weld area?

anyone have some pictures of aluminum Mig welds?

I guess thats all the questions I can think of now....

thanks Beaulieu

 

I would like to hear more on this subject with relation to spool guns. Bought one for my Miller, but haven't tried it yet.

 

from what I remember,you need to go a little quicker than steel as it heats up faster,Its been a while though.Also make sure to keep you liner as straight as possible so you don't kink the wire.Good luck.

 

I've had the most luck welding aluminum using a pulse type welding technique.

 

I have mig welded lots of aluminum on the job and one thing i can tell you is to make sure you have good ventalation or you will feel like you have a terrible hang over from the fumes.Its like welding on galvanized ,but seems worse.As far as the welding part ,i like to weld on a high heat setting and wire speed and move a little faster .It seems to work better that way cuz the aluminum melts easy no matter how you do it with a mig.I always use fairly clean metal to start with (fresh extruded) ,but as far as wire brushing first i never do and i havent had any problem with bad welds.Unless your gunna use a spool gun ,you better have lots of spare tips till you get the hang of it.Also make sure you run the lead cable out and make a big circle with it ,otherwise the soft wire will bind and burn the tip instantly ...

 

i've been doing MIG aluminum every day for a while now, and my best advice is do 2 passes. do one quick pass with high wire, just to seal up the joint, then brush it clean. then turn down the wire to a spray transfer and use a weaving motion.

i can get pictures of mig welds Monday is you still want 'em.

 

Why don't you save your money that you are about to spend on welding aluminum with a 110 wire welder and find a nice used tig mach! That is just my opinion!!!!!

 

Here is a link to what Miller has to say: http://www.millerwelds.com/education/articles/articles10.html

Here is what Lincoln has to say:
http://www.lincolnelectric.com/knowledge/articles/content/compactmig.asp

Here is what I have to say:
I don't think that you will be very successful with a 110v setup for GMAW aluminum. But, if that is what you got, then try it. I hate MIG'n aluminum and I have access to some nice machines. Spool gun or push-pull gun ($$) is the only way to go if you plan on doing allot of aluminum. Pushing a .035 wire of aluminum through a 6ft mig gun can be very frustrating.

 

Plan on screwing up a LOT of tips very quickly. Plan on cutting out a bunch of birdnests. Keep the whip as straight as possible. Plan on having some ugly weld beads. Have a very good brush just for aluminum, every time you stop to fix the ruined tip and cut out the birdsnest you will have to reclean the aluminum. A good grinder with lots of wheels help too, the aluminum melts into the grinding wheels real fast. Its a frustrating process until you figure it out, but if you don't do it real often, you have to refigure it out everytime. Occasional aluminum welding pretty well sucks. A spool gun makes life a lot easier, but occasional aluminum welding still sucks. Gene

 

Ya your gonna' screw up tips but that why you use a oversize tip .045 wire = .055 tip ... the wire expands so fast the if fuses itself to the tip befor it reached the puddle.

 

Very very helpful...thank you.

 

This man couldnt have said it better .I forgot about the bird nest of wire that immediately follows the burned tip .It can get expensive buying tips.At my job i have recomended to them to buy a spool gun but they wont .We have a nice Lincoln mig setup and sometimes when they need me to weld a bunch of aluminum in a hurry i can go through 20-30 tips in a day.Its their dime i guess ,but you may get discouraged quick if your the one paying for them.