I just received a welder, so now I get to learn how to use it (Hobart 140). When welding aluminum, does Argon gas always have to be used, or can you get by? When I start (someday) to make my plenum; for a EFI single-plane intake, what type and thickness aluminum would I need to use? I would like to have a curve to the top; what kind/size is bendable? As y'all can tell, this is a whole new ball game to me. Thanks for any help.

 

 

I have looked at a couple of Hogan sheet metal EFI intakes. they appear to me to be made out of .80 wall aluminum sheet stock. The bolt on Hat frames to the throttles is made out of 1/2 X 1/2 Stock.

Just look at some pictures of Hogan intakes and you can see what I'm talking about.

 

It's been a LONG time since I've welded Al, and don't know anything about the welder by model #. Is it a MIG or TIG welder? If MIG, I don't know if there's flux-core wire for Al, but maybe.... If TIG, then you need some sort of inert gas to keep the weld from oxigen intrusion that would develop without the inert gas shield (Argon and Nitrogen are the two most used, or at least were).

Also, welding Al has it's own special charecteristics. If TIG, does your machine have constant HF arc, or just at start? Do you know how to grind the electrode tip properly (Al is different than steel). And you need to clean the Al with acetone or similar (or scrub the hell out of it with a wire brush, etc.) to remove the oxidation on the oustide. That oxidation makes Al into aluminum oxide which melts at a higher degree that straight up Al, so in essence, by time you finally get the skin to melt, you've got a big puddle under your hot-spot just waiting to blow a hole in your work.

Do you have a votec school nearby? If so, a welding class would be a very, very good idea. Heck, the insrtuctor might be a gearhead and help you with the project!


Tim

 

Welding Al with a Mig is not impossible, but you will definatley need shielding gas.

AC TIG is whats commonly used, and best suited for welding aluminum.

 

I thought this post was long dead I agree, a welding class for me sounds like a good idea. Always wanted to learn anyway. Thank you gentlemen.

 

For aluminum use 100% argon for thin or 75% argon + 25% helium mix for thick - no reactive gases. The high frequency TIG machines help with the thinner aluminum for several reasons but not undoable with your little MIG. The small MIG machines are very popular for the automotive shops using it for thin sheel metal work as well as the thicker plates/frame metal - one small machine that does 99% of thier welding needs. The new welding machines are low in cost but way ahead of most hobbiests welding skills/experience. U will need to practice of course and the basic welding course is the best idea - insist on MIG training.

This book should be helpful: The Everyday Pocket Handbook for Gas Metal Arc Welding (GMAW) of Aluminum. $12 from American Welding Society order code AWS PHB-8

Good luck with your project.
cardo0

 

You don't have to use gas to wield aluminum. There is not going to be a load on it so you really don't need to bother. If you were wielding a frame then yes, use Argon.

Get gas-less wire. I have been wielding for 20 years and have only used gas a few times.

Go to the hardware store and buy some aluminum, play around with it at different settings. You will need to know how fast to feed the wire and how much power to use.

The quickest way to learn is to break the wields. You will see which is good (will look ugly at first) and which are not. If you can not break the wields it is a good sign. After you get good enough to hold the bead steady and get penetration (the key to wielding) you can start on your project.

Have fun.

 

Do u mean regular MIG wire ERXX-S-X or FCAW wire as EXX-T-X?

I imagine u are talking flux core (Flux Core Arc Welding - FCAW)? Well though i have never used FCAW i read in the welding text book FCAW is for ferrous (iron) metals only - no aluminum.

So if u are saying u can MIG weld aluminum without gas i would like to hear this is what u are implying. Or are u implying FCAW? As both methods are not recommended anywhere this is maybe a way to make poor quality welds that possible do work - but no-one would teach that or pass any inspection codes using it.

cardo0

 

tig welding aluminum is the way to go. i have done both mig and tig and i must say for the qualitly and neatness of the job tig is the way to go