How to Mig Weld Aluminum Tubing

I am curious about what I need to know about MIG welding aluminum. I have an old (15+ years) Blue-Point MIG welder. At the moment I am unsure of it's output amperage (I forget and it's in the shop right now, but can't check it until later). It does run off 110V and input amperage is 20A. It's a "true" MIG system for use with shielding gas, not flux core wire. I typically weld thinner sheets of steel ranging from auto-body stuff to 1/8" thick plates and use an argon/co2 mix as the shielding gas (75% argon/25% CO2).

I searched for Mig Welding Aluminum and came up with no results which seemed strange that no one asked this before.... but what do I need to know about MIG welding aluminum compared to steel?

The application is pretty much the same as my previous steel jobs just in aluminum: thin sheet metal up to plates up to maybe .250" or possibly even thicker. A specific customer wants to know if I can weld some thick-walled aluminum tubing at right angles to each other. For steel, and I assume the aluminum, I would first notch out the end of one aluminum tube with large end mill or hole-saw to fit around the OD of the other tube, and bevel the edges of the notch for the weld to fill in.

My MIG welder will accommodate a spool of .030" aluminum welding wire, available from my local hardware store. So my questions are:

1) Should I use the same shielding gas? Argon/CO2
2) How much amperage will I need to weld aluminum? I know it's application dependent so use for example a 1.5" diameter aluminum tube with .125" thick wall welded as described above with the end of one tube being welded to the OD of another tube.
3) Is the "standard" welder polarity for use with steel welding with gas shielding work? I've heard that flux-core welders use a reverse polarity, but mine is not selectable. I might be willing to buy another welder if mine turned out to be unsuitable since it's not a great welder anyway.
4) Any special techniques I should know about?

Thanks for any and all help!

Hello,
I think you will need a TIG welder to do decent work with aluminum.
I am not even sure if it is possible with a MIG welder, but you will probably have other replies to help with that.

To Metalworkz:

Thanks for the reply. I didn't know if MIG welding aluminum was possible, but when I saw the roll of aluminum wire for MIG welders at Home Depot, I assumed it was possible.

I have TIG welded steel in the past, and I know it can be used for aluminum. I would really like to have a TIG welder if I could afford it :-)

Hello again,
I did a google search and found some interesting information regarding welding aluminum with a MIG welder:

http://www.lincolnelectric.com/knowl...compactmig.asp

Apparently it is possible and they actually discuss it there. Maybe I should have did the search before replying.

You will probably need a spool gun, as the aluminum wire is so soft that your feed rollers won't be able to push the wire down the whip. You can also get low friction liners for your whip, but I've been unsuccessful with them too.

I think pure argon is the gas of choice for migging aluminum. Your joints should be supper clean before attempting.

Good luck, it's nothing like welding steel at all.

Paul

Mig welding aluminum is definately doable. You will need a teflon liner, straight argon, a larger tip, and different drive rolls specifically for aluminum. Welding aluminum is possible with a standard mig welder without the push/pull or spool gun if you have a short whip and take care to keep it as straight as possible. Longer whips will have too much drag and you will end up with a birds nest at the drive rolls. Drive wheel tension is extremely low compared to when welding steel. I suggest a trip to your local welding supply store with all the info for your welder, I'm sure they will be happy to help you out and set you up with all the items you need.

If you plan on doing alot of aluminum mig welding (more than a few occasional welds) I would suggest a push/pull setup or a spool gun. The good news is, welders and spool guns have come way down in price compared to what they used to be.

Brad

There is some mig welding information here.
http://www.learn-how-to-weld.com/mig...-aluminum.html

You will need pure argon as someone else has said already.

The amperage is gonna be about the same maybe a little less than the steel. You might wanna take a torch and preheat the thicker aluminum as it is very porous and the heat from the weld will dissipate out of the weld area fast and into the surrounding area

For the polarity you will need a/c positive. Opposite of steel

Make sure its clean and might have to move a little quicker than steel and for the motion when used to MIG aluminum I moved the tip of the gun in cirlces although you can do moon shapes also.

If you decide you need to buy a new welder theres a site called cyberweld.com i found to have the best deals a few years ago when i bought my MIG/spool gun setup and then a again a when i bought my TIG..

I hope this helps. Best of luck

The others have answered most of your questions.
You can mig al but a spoolgun will do the best job.
100% argon shielding gas is required for this. Argon/co2 will not do.
Mig welding al with a small 120v welder is not the best idea. A 230v mig welder will do a far superior job for this and yield superior results.
AC tig will do a superior job for welding al than any mig welder will do.

My friend does it with aluminum wire, argon and he had to upgrade his feeder.

Wow, thanks for all the replies. It looks like I would need to do some serious upgrades to my MIG welder if I were to try this. It'd probably be a better idea for me to sell my current MIG welder and buy a better one, or maybe just save up and buy a TIG welder.

If anyone is still monitoring this thread, I have a question: What do you think about the budget TIG welders such as sold by Harbor Freight or Northern Tool? I would would really only need to use it on rare occasions, but on those occasions, I would need a quality weld. Well, I should say a machine that is capable of a quality weld, my inexperience aside. Are those Harbor Freight machines even worth considering?

The old saying comes to mind.......you get what u pay for.

TIG will need some good amperage and an AC high frequency output.
You wont get this on a cheap TIG
You will probably want minimum 220 amp for 1/8 aluminum welding

I agree The old saying comes to mind.......you get what u pay for.

It's like the old argument isn't it. If you only going to use it once in a blue moon then you will be right. For that price it will not be AC which means you can not do Ally welding. I think the main reason people want a TIG welding machine is because of the versatility as the want to weld mild, stainless and aluminium etc.

You wouldn't see these being used in a proper welding and fabrication shop, well I have not seen them being used.

But then again for the DIY guy at home, if you want it for tig welding stainless or mild steel, thin sheet material etc, IT WOULD DO THE JOB.

"You get what you pay for." Eh...it's relative.

Even Lincoln and Miller welders are made in China now.

A really decent welder that is far more affordable than the Lincoln or Miller is the Everlast PowerUltra205 and PowerPro265...this has the added plus of being an inverter TIG, stick and plasma cutter.

Yes I own a couple of the Everlast models, and they are the best bang for the buck I have ever seen.

Bypass all the Harbor Freight welders (except the spot welders), bypass 90% of the home improvement welders.

There is higher performance at a lower pricepoint available out there, you just have to look.

I just saw the american chopper episode where they visit the monster monster size Miller plant. I saw all kinds of tig welders being manufactured there in america, not china. I dont doubt some of there stuff is sourced from china.

Quote:

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Originally Posted by 307startup

"You get what you pay for." Eh...it's relative.

Even Lincoln and Miller welders are made in China now.

A really decent welder that is far more affordable than the Lincoln or Miller is the Everlast PowerUltra205 and PowerPro265...this has the added plus of being an inverter TIG, stick and plasma cutter.

Yes I own a couple of the Everlast models, and they are the best bang for the buck I have ever seen.

Bypass all the Harbor Freight welders (except the spot welders), bypass 90% of the home improvement welders.

There is higher performance at a lower pricepoint available out there, you just have to look.

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Quote:

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Originally Posted by diyengineer

I just saw the american chopper episode where they visit the monster monster size Miller plant. I saw all kinds of tig welders being manufactured there in america, not china. I dont doubt some of there stuff is sourced from china.

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What is still manufactured here are the industrial, generator driven and line-specific welders.

Not just sourced components are from China but many of the non-industrial machines are made there too.

That's a fact Jack. The Made in the USA sticker is pure profit-pandering off the warm-fuzzy memories the brand labels used to inspire.

Did you really think that the board execs gave 2 ****s about the human beings in our country who were affected when they started outsourcing...or was the extra jingle in their pocket all that they could think about?

You be the judge, but don't be too sentimentalist about it...they sure as hell weren't. If you honestly still think that Made in the USA (with foreign sourced content) sticker and brand loyalty is worth your hard-earned greenbacks...then don't feel sorry for yourself when the favor isn't returned. It's nothing personal, just business! ;)

OH for sure. Like i said, i saw some stuff being made there, and im sure even more is from china. To be "technically" made in america, which is a huge joke/hoax, one could simply throw a final bolt/sticker on and could market it american made, or many other tricks they pull.

It is very sad though. I believe with superior technology we can do everything they could do @ the same price by using our damn brains. Might have to pay everyone minimum wage but hell atleast the jobs are here and not there.

sad times.

Quote:

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Originally Posted by 307startup

What is still manufactured here are the industrial, generator driven and line-specific welders.

Not just sourced components are from China but many of the non-industrial machines are made there too.

That's a fact Jack. The Made in the USA sticker is pure profit-pandering off the warm-fuzzy memories the brand labels used to inspire.

Did you really think that the board execs gave 2 ****s about the human beings in our country who were affected when they started outsourcing...or was the extra jingle in their pocket all that they could think about?

You be the judge, but don't be too sentimentalist about it...they sure as hell weren't. If you honestly still think that Made in the USA (with foreign sourced content) sticker and brand loyalty is worth your hard-earned greenbacks...then don't feel sorry for yourself when the favor isn't returned. It's nothing personal, just business! ;)

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Quote:

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Originally Posted by diyengineer

It is very sad though. I believe with superior technology we can do everything they could do @ the same price by using our damn brains. Might have to pay everyone minimum wage but hell atleast the jobs are here and not there.

sad times.

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The Chinese are just as, if not more than, technologically advanced as we are. Don't fool yourself for a minute, they can do Quality work for the right price, not the cheapest price.

When you factor in the price of shipping, QC staffing, and manipulated currency...the US is still cheaper to produce most products.

Technology is expensive, manpower is not. (For the price of a full seat of MasterCAM, support, dongles, license and maintenance...you can pay a programmer's salary to write your OWN software. Think about THAT.)

This is what I don't understand though...if we pay all of our workers minimum wage, just who the hell are you gonna sell to? No middle class, no disposable income.

I don't care how good our poor (American) have it, they aren't driving new Chevy's or living in McMansions...they drive clapped out beaters and live in shoebox-sized apartments. You CANNOT have an economy or industry to support it when the majority of folks are making peanuts.

Quote:

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Originally Posted by 307startup

The Chinese are just as, if not more than, technologically advanced as we are. Don't fool yourself for a minute, they can do Quality work for the right price, not the cheapest price. .

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I have to agree. I like to trash them as much as the next guy - However IT IS OUR FAULT or rather "corporate manufacturing in North America".
They go to China and say I need this part made for 5cents each.
The Chinese factory guy says for 5 cents I give you a **** part but if that is what you want, OK .

It's all about You get what you pay for this way we just have a scape goat.