Welding Aluminum MIG or TIG?

[Veselin Kolev]

1. you need aluminum feed wire
2. you need pure argon gas (not CO2)
3. If you're welding a chassis, and you weld the top side first and then the bottom, the entire chassis will curve upwards. Hence, first tack weld the entire thing together and then weld top-bottom-top-bottom, etc, flipping the frame over every weld. And make sure you do the symetrical side so you dont get corner warping.

If it's your first time welding aluminum, practice a lot on scrap metal first. Make sure everything is grounded cleanly and securely. Sand the oxidation off the ground contact and the places that will be welded.

Other than that, MIG and TIG welding can be almost equally as effective. In my experience TIG makes a better looking weld, but in FIRST I doubt you care.

[jmcglash]

Starting with the filler 4043 is easy to weld with compared to 5056 but 5056 feeds better in a mig setup.

Argon gas is a must

CLEAN metal is a must. NO sand paper (aluminum oxide is evil). Scrub
with a stainless steel wire brush.
AlumiClean - Aluminum Cleaner & Brightener will strip all oxides better than a wire brush.

8020 and the like is Anodized Aluminum and the anodized layer must be
removed first. Dollar store oven cleaner is lye (Sodium Hydroxide) is a
spray can and will remove the anodized layer in about a minute.

4 part each weld, looking at the clock face 1-3 6-9 3-6 9-12 and skip
around the piece. this will keep the heat down. Even so clan the part
well.

The advice to practice on some scrap is very good advice.

Good luck and have fun with it.

Jim

[Daru]

We had an expert welder come in to weld our chassis for us. (who just so happened to be my girlfriend's brother) He used a TIG welder (preference? don't know), and the welds look very nice and clean.

He didn't clean any of it, he told me that you only need to clean the oxidation off if you aren't a good welder It's contrary to what I have read (everywhere), but eh... he's the welder Something about not heating it too long so you blow a hole in it...



Now to what I personally believe. I have welded only steel with either a MIG or a TIG welder. I am by no means an expert welder, but I can manage to make two peices of metal stick to eachother.

I find the TIG welder easier to manage, it's small and light, but you need a good pair of steady and coordinated hands. I also think TIG is brighter, so it's easier to see what you're doing.

I get neater looking welds with a MIG welder, and you don't need to be as steady or coordinated. It also helps to use two hands on the one thing, so you can keep it a little steadier.

--- im rambling...

I think if you're set up to do aluminum on a MIG welder, go for it. If you've never welded before, get a few hours in on steel before even trying aluminum. MIG is easier to get the hang of, and it will definantly suit your purpose.

Good luck!
Dave

[razor95kds]

We weld aluminum all the time with a Mig welder and it works perfectly. You defintely need pure argon gas and your welder should move pretty quickly while he is welding. we crank the voltage and the feed rate to the maximum settings when welding .125 in thick bars. Aluminum isn't extremely difficult to weld on, just remember to move quickly and practice on the scraps you can.

[sanddrag]

Originally Posted by razor95kds

We weld aluminum all the time with a Mig welder and it works perfectly.

Can you please share make and model of the welder, spoolgun or standard feed, and post a picture of one of your welds? Thanks.

[=Martin=Taylor=]

Originally Posted by razor95kds

we crank the voltage and the feed rate to the maximum settings when welding .125 in thick bars.

Or... You could do the opposite, which would be easier. I'm no pro, but I have more control when the feed is low.

If its your first time welding a frame I might suggest that you be liberal with the welds. Although they may not have the beauty of a thin bead a thick weld will have a better chance of getting maximum penetration. Don't be afraid to glob it on.

(but remember to alternate between welds to avoid warpage)