welding cast aluminum

[onebadpig]

Cast aluminum is typically very dirty metal. I'm guessing this is where you want to adjust the AC balance on a TIG welder for more cleaning action. Am I correct?

My welder is the Hobart EZ-TIG 165i which does not have any adjustable parameters. It seems to do well on clean metal but as my TIG skills increase I'm beginning to see just how much of an entry level machine it is. At least I bought mine used for half price.

[Dale M.]

I believe best process is to remove any corrosion by various means (light abrasives), and a final burnishing surfaces with stainless steel brush only used for the purpose and not contaminated by using on other materials...

[Hunter55]

Dale is correct, clean, very, very clean. I once welded said material with my 165 and it turned out better than expected. I also have welded material thicker than 1/4 with mine successfully. It just takes patience and much practice to hone your skills.

[Sberry]

Some cast welds well.

[Hobart Expert]

As the others have said, it can never be too clean. How it welds is typically going to depend on where/how it was used. Cast aluminum engine blocks/heads for instance are typically impregnated with hydrocarbons which makes them a pain to weld, while other cast aluminum that has never seen oil or grease may weld similarly to extruded aluminum.

[onebadpig]

I'm playing with automotive intake manifolds. I have several I'm toying with, some used and a couple unused. Even the unused ones weld dirty and the used ones are worse.

I can only grind away so much material. I have to leave enough to work with. I've used the stainless steel brush and acetone and they just don't clean up enough. Wouldn't this be a situation where it would be nice to be able to adjust the AC balance?

[metallurgy]

In my limited experience, seems that adjusting balance towards EP yeilds a tungsten that gets dirty a lot faster. Potentially useful but not magic? Line up a couple electrodes and clean up when done with the job?