What DO you need to weld aluminum?
 

So my dad has a welder because he is building an airplane right now. I used the welder to weld up my exhaust and that turned out OK. I know that this welder is supposed to atleast be able to weld aluminum because he bought it to weld aluminum parts for the plane that he's fabricating.

I know welding aluminum is supposed to be hard.b ut I'd like to know what the difference is and what you need to do it as opposed to welding steel.

Thanks
-Ryan

ME TOO.I want to design some bike shit cheap.

You can do it with DC, but it's going to be really hard. Get an AC welder, either tig or mig and you should be fine.

Aluminum burns through REALLY easily. I'm not sure what you need to weld it, but maybe a different gas mix and different wire?

1. mig welder you can run reverse polarity on
2. teflon or dedicated steel liner and STRAIGHT run of feed
3. argon
4. the right grade of aluminum

that's the easy way. I do it with my cheapy lincoln welder but it's not super pretty. you can buy some sheet to practice on at mcmaster. they tell you what's easy to weld.

Yes welding aluminum is pretty hard. It does melt through very quick and in my experience you can't really see the coloration change and puddle leading up to your weld melting through like with steel. Make sure you practice a little bit before you try to do your welds on your final pieces.

Dont forget:
Dedicated stainless steel wire brush. If you use it on anything but aluminum it will contaminate the brush and make it un-usable.
It makes a pretty big difference. Also once you brush what you want to weld, acetone or something similar also helps alot to get the weld extra clean.

great info thank.

The welder was ~$600. It's a MIG and it can run Argon.

What do you mean by straight run of feed? This welder runs the feed of flux from a spool inside the welder through the tip of the gun, is that acceptable?
And what about the teflon/steel liner? I don't know what you are refering to here.
Oh, and do I use a specific type of flux or anything?

It seems everybody just steers clear of trying to weld aluminum and just sticks to mild or SS most of the time and I think its about time that we get some good info up on what you do need to give it a try - we may end up with some people doing some great aluminum work soon! I hope to start experimenting with this very soon.

Thanks for all the helpful info so far!

-Ryan

STRAIGHT means you have to be careful not to bend the feed line. Because aluminum is so soft, any resistance in the line cause the feeder wheels to chew the wire up and slip.

sage advice - cleaning area to weld thoroughly makes a big difference

I have a MIG and tried Aluminum. It was not pretty. There a couple of guys here that do it all the time at work (aircraft stuff) and they say because aluminum conducts heat so well it is an art to get it correct. You will need a good unit with a foot pedal power control. You have to cut back on power closer to an edge as the heat has no where to go and it just starts to melt the aluminum badly. The setting in the center of the piece is much different than at the edge hence the need for a foot control. Done correctly nothing looks nicer than a good alum weld.

straight run.. just keep the gun and feed cable straight like m2 said. nothing sucks like a birdsnest in your welder every 2 minutes.

teflon liner is for the same reason. you can find them at most shops if it's a standard welder. Just call em up and tell them what you have and they will help you out.

the liner is basically a long spring like a bicycle brake line covering that the wire slides through. since aluminum is so soft and prone to getting stuck (not slippery), the liner has to be slippery and not have all those internal edges to work well.

you CAN use the standard liner but you'll want a fresh one that's dedicated to feeding aluminum and you'll have to use it when and only when you weld aluminum.

Matt

A tig setup w/appropriate filler rod. Not that hard to weld aluminum with a tig. Most stick welders out there nowadays include a tig cup hookup. TIG = great low heat pretty welds + a little more technique than MIG. If you already have experience with mig, find someone with a little xperience on tig to show you the finer points an you will be sticking aluminum together with decent welds in no time. Believe it or not, welding aluminum is not as uncommon as you've made it seem.

With a good tig setup it's fairly easy to weld aluminum. I was throwing down some awesome beads the first time I welded aluminum, I just need to work on consistency.

If you want to MIG aluminum get a spool gun... anything else is a waste of time, otherwise you want to use a TIG welder.

Mark

nah, it's just a little tricky. it can be done with a push feed. especially if you're cheap :)