cheapest welder for aluminum?

i need to weld 3/16" sheet aluminum for a boat i'm making and want to do it at the cheapest cost. this welder ( says it won't do aluminum (and i'm not sure 90 amps would be enough anyway). Is that true? What if i bought the 180 amp model? Any suggestions for other welders?

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sunset12 years ago

are you fixing a spot or making a patch?

I just watched some videos of guys using alumiweld. from harbor freight.

im fixing a cast aluminum bbq base and might try it. good luck

WWC5 years ago
I bought a Harbor Freight welder a number of years ago. It would weld half crappy for 2 minutes then not at all after that. You always have to watch out for Harbor Freight stuff.

So my point is that your title " cheapest welder " may not be a greatest choice.
I've heard that using a bottle of hydrogen with a normal oxy-acetylene torch works well on aluminium, so that could be cheaper if you already have a torch and oxygen cylinder available. The only things you need to worry about are getting a blue filter for your welding mask, and the cost/availability of hydrogen cylinders.
ridecruz88 (author)  The Skinnerz5 years ago
And the actual welding would be with an aluminum rod? Would that system also work for steel if I needed it?
Yes, it works with steel, but your HAZ is very big.
And your skill level. Gas welding aluminium is an artform. One false move, and you have a hole you can drive through.
There's no such thing as "flux core" wire for aluminium, so you need a proper MIG with a bottle of welding grade Argon.

Welding Aluminium with a MIG is a pretty tricky process at the best of times. If you want decent weld quality (penetration, inclusion free etc) you need a GOOD set, aluminium rollers, with a U slot and a teflon liner in the torch. 180A should just about weld it, but aluminium is finicky stuff.

Also, the duty cycle of cheap welders can be as low as 30%. If you have big joints to do, you'll struggle with "cheap".