Our team is thinking about welding aluminum. Our problem is we can’t TIG weld because we don’t have the machine nor the experience. Now we have a Aluminum MIG welder, but the aluminum tends to warp due to the heat. How do we MIG weld accurately with minimal warping?
Go to http://www.hobartwelders.com/mboard/ and search around. Aluminum welding isn’t exactly easy, but it can be done. There are some really good weldors there. Search around before you ask a redundant question.
- you need aluminum feed wire
- you need pure argon gas (not CO2)
- 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.
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
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
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.
Can you please share make and model of the welder, spoolgun or standard feed, and post a picture of one of your welds? Thanks.
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)
my best suggestion for tips on welding is going to the miller website and looking at their tips pages here
as for prefence i dont have one because i have only used TIG and stick welding.
My high school shop teacher (who was an accomplished steel welder), compared MIG welding aluminum to “melting two sticks of butter together”. He never was able to get the hang of it, even when we brought in new, better equipment.
You might want to lacate your local Miller or lincoln suppler when i set up my shop we split it 40-60, 40% tig’s and 60% migs and I have learned over the years that a good percentage of my students do much better with the tig process rather than mig when it comes to alloy welds, Spool guns are a lot harder to manage than a tig turch if you can braze tig is the way to go…
most of the supplers will rent the equipment at a fraction of the cost and will answer most all your qustions. If your looking to buy a machine I would look at a Miller Maxstar tig price range is around $800.00 complate it is portable and will run on 110 or 208 volts and will weld up to 1/4" aluminum with no problems we run a helium process on most of our aluminum projects including the robot frame how ever Argon works well also… When welding just mak sure your parts are clean you have a good fit-up and clamp your parts take your time you will produce a much better weld.
Good luck
I strongly urge you to ask around the community in order to find an experienced welder who would be willing to do critical welds for you and also share as much experience as he/she can. Most welders enjoy what they do, and I’ve never had any trouble getting them to donate some time or getting them to talk.
I’ve learned a bit about welding from written guides, a lot from watching and talking with an experienced welder and the most from just sneaking in an hour here and there in the welding shop messing around on scrap. The more time you spend looking at puddles, listing to the arc and getting a feel for heat the more natural welding becomes. There really is no replacement for making mistakes when it comes to learning a new skill.
So, ask around at a welding supply store for any welders that might be interested in helping out your team. You might offer to pay for con$umables, and he might offer to supply equipment. You might get those pretty TIG welds yet!
-Andy
TIG, for sure. Look around in your area for a welding supply company and see if they offer classes. Maine Oxy in New England has some good classes.
This is truly an art, but not a black art. The key is knowing how when to stop before getting into serious trouble (melting the ends of your stock) and how to fix mistakes.
Then…
Practice.
Practice.
Practice…
To see some nice TIG welding, check out Episode 3 of American Robot.
you need tunksten wire thats all i know
If you want to see some absolutely beautiful TIG welds, check out this guy (scroll down aways):
http://mywebpages.comcast.net/engloid/workpics/workpics.html