Repurpose aluminum wire for welder?

[starquestMM]

I currently have an electric stove and am going to be switching to gas. I had the idea to reuse the circuit for 220v use in the garage and was looking for a sanity check on if this would work. Stove is upstairs and garage is in basement, so its easy to physically move the end where it needs to be.

Its aluminum 8-8-8 xhhw installed in 70s.

Is 40a the correct rating? I would probably use it for a welder at first and maybe upgrade my 110 compressor some day.

Thanks
Mike

 

[Aceman]

I wouldn't use it if it's from the 70's. Aluminum nowadays is a different alloy then the stuff they used back then that had all the problems. I wouldn't take the chance myself, I'd junk it.

I'd rather see copper on a welding circuit myself. The reason they had so many failures is aluminum heats up and expands and cools down and retracts. It works the connections back and forth until they finally start loosening up and then that creates heat. So when you want to use old aluminum with a welder that draws a lot of current and then stops. Then draws a lot of current and stops, etc. you're doing exactly what you don't want to do. Warming the wire up and then cooling it down. Scrap it.

Just my opinion.

 

[pattenp]

Is that early 70's or late 70's? Also #8 Al SE is 40A. Well actually it's rated at 35A @ 60C by NEC, but can be over current protected at 40A.

Edit: If installed after 1972 the Al wire should be okay to reuse.

 

[starquestMM]

House was built in 1973, mabye I can find some more markings on the wire itself since its near that cutoff.

 

[pattenp]

If you do reuse it make sure to use Noalox paste on all the terminations and tighten them well.

 

[DonnyT]

My house was built in 73 as well. I have aluminum wire through out with some copper. I pig tailed most of the aluminum wire outlets and used a receptacle/switch rated for aluminum wire. Yes plenty of Noalox.