You need Nitric Acid and Methanol.
Or stainless pickling paste. The nasty ones.
30+ years ago the shop I worked in had a guy tigging aluminum all the time... Used to use hydrofloric acid on everything and in those days they sprayed it around like window cleaner. The only warning on the gallon jugs it came in was it "may" cause burns if left on skin! Looked it up recently and there was a whole booklet about it online warning about amputation usually being the safest treatment for inadvertent exposure, and how getting 6 square inches of wetted skin was usually fatal!!! The things you do when you're young and foolish. (And some employers could get away with considering "the help" expendable. )




