Amperage required for TIG welding aluminum

[cjjonesarmory]

I have a project that requires welding of .750" and 1.000" aluminum plate with butt welds.

My welding knowledge is somewhat limited, I have used both MIG and TIG on steel, but not on aluminum.

I do not currently have a TIG welder and would consider buying one, but not sure how much amperage a thorough weld in such thick aluminum would require. It is a "test project", so if the amperage is astronomical, I may consider having someone else do the work, or just using 1018 steel for the prototype (which I am capable of welding). I have limited electrical capacity in my shop, and a high amp welder may not be useable....

I know welding aluminum takes more amps, just don't have any experience with it....

[DareBee]

250 to 300 amps for that

[Cartierusm]

The welder needs to be that high, but that's not what your plug in the wall needs to be, you'll probably need 90 amps AC at the plug and a welder that can do 250-300 amps. If you've never welded aluminum let some one else do it, very hard. And not all aluminum is easily weldable, so make sure you buy the correct grade and not unknown scrap. 6061 is great for welding.

[H.O]

Can't help with the amperage but I'm pretty sure that for aluminum you need a TIG-supply capable of AC while welding steel works fine with DC. Not all TIG-supplies 'do' AC....

/Henrik.

[cjjonesarmory]

Thanks. It looks like this may be out of my capabilities. I'm sure I could learn to weld aluminum, but I don't have the budget for such a large welder nor the electrical capacity to run it.

I guess I'll either make it out of steel, or have someone else do the welding.

Regardless, thanks for the info!

[Cartierusm]

What are you making?

[cjjonesarmory]

Machine parts. It's a high speed spindle for my Novakon NM-200 mill. The structural components will be steel, but I wanted to make certain parts from aluminum for lighter weight, ease of changing out the parts.

[Cartierusm]

Hmm. Where are you located? I've got a 300 amp TIG, can I tig over Skype, I heard it can do anything.

[Nastyzen]

In the past I've welded Al. with the arc process.Call your welding supplier and ask him about the availability of welding rods for your arc welder.I think you have to have a dc reverse polarity capable machine though.
It might be a cheap and effective way out.
I mig weld most of the heavy plate work around here if esthetics d'ont matter with my 250 amp welder.It has a 50amp breaker.
If it has to be nice I t.i.g. weld with my 300 amp water cooled torch welder,95amp breaker.
Anybody can arc weld.
Good luck

[Cartierusm]

Nasty makes a good point, arc weld it and grind the edges to a Vee, then weld, grind off the weld check it and reweld if necessary.

[cjjonesarmory]

Originally Posted by Nastyzen In the past I've welded Al. with the arc process.Call your welding supplier and ask him about the availability of welding rods for your arc welder.I think you have to have a dc reverse polarity capable machine though. Good luck

Well, I have a MIG currently. Is an arc welder the same as a stick welder? Not sure I want to buy a stick/arc welder if the appearance will be poor... I've never arc welded before either....

Maybe the most cost effective way to do the aluminum parts is to machine them from blocks. The parts which I want to make from Aluminum could be machined from 2.5"x3.0"x5.25" aluminum blocks.

[keebler303]

Or you could bolt two flat plates together? Use some socket head cap screws with a counterbore and no one will be the wiser. Put in some dowel pins if you really want to be crazy. Much easier than having to tig weld it or hogging out big blocks.

Matt