Welding 1/4" aluminium?

I have a need to weld 1/4" thick aluminium square tubing to itself. What is the most economical method to do so? I don't anticipate ever having to do thicker - but will certainly do thinner.

I am proficient at using my little flux core - but have never welded aluminium.

Have you considered that special aluminum brazing rod stuff? Supposed to be stronger than the aluminum.

Another vote for brazing

It doesn't sound like you have the tools to do this, are you asking what welder you need to buy? For MIG it would take over 180amps, a spool gun loaded with 4043 wire and 100% argon shielding gas.

To TIG you would still need about that many amps and argon, just no need for a spool gun.

Is a 200 amp syncrowave in the budget?

The main thing we need to know is what type of penetration do you need to achieve?

1/4" aluminum, as Jumper has said, will require a significant amount of amps because aluminum absorbs and radiates heat very efficiently. As a result it takes about twice the amperage of steel to achieve the same penetration.

my advice would be to purchase a TIG welder if finances allow. I was TIG welding today and it is very nice to be able to swap over a few settings and move from steel to aluminum. If finances do not allow, a set of bottles and a torch welding kit would be my next suggestion. torches can do most anything a TIG can do.. albeit less precise.

I would advise against a MIG for aluminum. Unless used in a production setting it will quickly become a PITA. Aluminum MIG rod (fill rod?) likes to jam because it is so soft. Aluminum MIG welding should also utilize a spool gun which is a additional expense. I think your overall cost for a MIG machine for aluminum would be equal to that of a TIG.

JB it.

If it's not a structural application, braze it. If it is, get a TIG, or if you're especially talented, oxy acetylene.

What is this magical aluminum brazin g rod you guys speak of?

I'm building what essentially amount to shelving. Each shelf is 18x36" and needs to support 300lbs.

Can you cut some of the tubing into 2" lengths and drill/bolt together?

Not going to be economical to buy a welder. You'll need more than 200 amps for tig, if you're doing much more than one joint.

Have you considered rivits? If the joints are overlapping its a perfectly acceptable fastener for the job. Millions of airplanes can't be wrong?

I'm building high density breeding habitats for a WET laboratory. I can't use dissimilar metals due to bimetallic corrosion, it is a humid environment.

I hadn't thought of rivets - I think because of the spans I need to cross, they wouldn't be so good - but I could be wrong.

If I preheat, will a 200A MIG with a spool gun work? Specifically looking at the Hobart 210MVP/Spoolrunner 100.

I've done plenty of MIG - though not aluminium, but never TIG.

There are 1/4 inch rivets that should handle the load. 1300 lb shear strength for aluminum. You will need the proper rivet gun. Either a big hand powered puller or better yet a hydraulic one. http://www.hansonrivet.com/pop-structural-blind-rivets.htm

You can also stick weld aluminum if you have a DC welder, forgot about that one. Weld the 1/4" and rivet the thinner stuff?

Went to Northern to buy the Hobart 220MVP, got tempted by their Klutch 220si. Brought it back to the office, grabbed 150C.F. of Argon, ran a new 50a circuit, and proceeded to spend multiple hours practicing.

Im really happy with it!

Experimention today showed that most of the rest of this project will be 1/8th instead of 1/4, so cost dropped a lot. Plus I saved 400 on the welder over my estimates.

m4ff3w wrote: Experimention today showed that most of the rest of this project will be 1/8th instead of 1/4, so cost dropped a lot. Plus I saved 400 on the welder over my estimates.

Gotta say I was wondering about the 1/4" wall Takes some serious heat to TIG that.

Tips with TIGing alloy:

Clean the surface with a SS brush that gets used for nothing else.

Wipe with acetone to clean off any oil

Wipe your welding rod down with a scotch-brite pad.

Dont weld ON the rod, but dont let the rod out of the gas envelope either. (good luck with this). What you will see happen is that the rod balls on the end of the filler rod up rather than flowing into your bead.

You will most likely want to bevel the 1/4" stuff and maybe even do two passes.

Going to get mighty hot on the TIG torch unless you have water cooled.

And by the way, Props for embracing a Major tool buying opportunity.

Success!

Proof of concept proofed. Next racks will be all be based on 1/8" tube though. We did 1/2 of the rack in 1/4" and 1/2 in 1/8th and the 1/8th works fine and is much quicker for me to fabricate with.

I'll be nice to go back up to OKC in a few weeks and work more on the setup.

I also learned how to sucessfully bond Acrylic aquariums. That was fun. The first 36x18 tank took awhile to make, but I made the next two in under an hour.

PICS!

So you welded 1/4" Al with MIG? Did you get the spool gun or just run the Aluminum wire in the regular one?

In reply to Dr. Hess:

Yes. The welder came with a spool gun. The 1/4 required preheat.

http://www.northerntool.com/shop/tools/product_200631881_200631881

100% argon and Hobart 4043 wire.

As an aside aluminum can also be bonded / glued. I volunteered for a FIRST robotics team and that is how we built the chassis, simple cut gussets bonded to the tubes. They can be clamped by clamps or rivets or screws. Its cheap and simple.

Can use 3M 5200 or many other adhesives.