Moin, the constant sult over the alu corrosion leaves me no rest. Various test series with aluminium inlaid in E85 remained of course resultless, so I started a short time a further attempt. – Take off an aluminium tube – loop the passivation layer – Heat the whole thing with a gas burner on a few hundred grad celsius – And dip the thing then in a glass 96% ethanol. The whole gives a funny film boiling during immersion n: http://www.youtube.com/watch?v=qOIhWeowxQM That’s what you do for a whole evening… And then you find out from the alcohol damping that the alu has slightly discoloured on the remaining passive layer, but only there. I can’t say if the residue of the dedensing agent is now, for example. The bare aluminium doesn’t seem to be discoloured. I guess, without high pressure, it won’t be anything, and I conclude the short experiment as resultless. Greetings