Are any of those aluminum cleaners suitable for use in cleaning aluminum before Tig welding?
Seems like sanding oxidixed aluminum gets some of the grunge but grinds the rest of the oxide into the surface of the metal - is it better to try and etch it off with acid first or on the other hand are there Al cleaners that work or fluxes designed to help with getting the bead to wet when metal is oxidized on the surface?
I've seen more experienced Tig welders welding some pretty crummy looking aluminum (old propellors etc.) so there must be some tricks to it.
Apparently more electrode positive time (indicated as lower "% negative balance" on Miller machines) accelerates the Ar ions so they bombard and clean the surface - any other tips?
We used to clean telescope mirror plates under low pressure argon with high voltage so that we could aluminize them - same principle (the low pressure allows the Ar to accelerate even more before they get slowed down bumping into another gas molecule)
Maybe I should be giving my old aluminum pieces that need to be welded a bath in Ar with a few kV applied to really clean them.