Can electrical aluminum pipe be welded?

[Steve G]

Hey Guys,

I just opened up my new HH210 MVP w/ spool gun, hooked up to argon and some 220v to try the only aluminum I had laying around, AL electrical conduit (I have a shipment of the real stuff coming tomorrow).

The reason I ask is that the welds came out really crappy, no penetration or burn through and lots of spatter. I had the argon at about 20-25 using 4043 .30 and 5/70 on the machine.

Thanks,

PS, any tips on welding AL or good articles, older threads, etc... would be great!

Thanks,

Steve

[shovelon]

Are you sure it was not coated with varnish or anodize?

[Blacksmith]

Another post on here indicated that electrical conduit was most likely coated and had a lubricant inside to aid wire pulling; all of these would interfere with welding.

[Steve G]

I realized that I had not had the hose pushed all the way in for the argon cylinder when setting it up. This was my first time setting up to weld AL.

It works like a dream now! The pipe is weldable.

[Pat]

Steve,

I find that just about anything under 1/8" thick does not do too well with a spool gun. I blow holes big time. I had some aluminum tubing that was approx 1/16" wall that I soldered/brazed with some Harris Alcor. It did a pretty good job, but as far as the strength goes, I guess a lot depends on how you are going to use the finished project. What diameter and wall thickness, and what is the intended use.

[Roger]

Aluminum has hot short problem. Hot aluminum weld expands more than steel then contracts before thin aluminum weld has enough strength to withstand contraction force. Cooled aluminum weld then has crack down middle of weld. Thinner aluminum can be Pulse MIG welded or TIG welded without hot short problems.