GESchwarz; you mentioned getting an alodine kit. Consider getting: [FONT="]Iridite 14-2 chromate conversion concentrate is available from McDermid, Inc., #8659 This is the same thing as alodine (and a lot cheaper than getting it from Aircraft Spruce, etc.) I think McMaster-Carr carries it.[/FONT] [FONT="] [/FONT] [FONT="]Distilled water produces best results. However, rainwater caught from the roof is very low in mineral ions and is an acceptable substitute (discard the first five minutes of runoff – that is the roof rinse water & is dirty).[/FONT] [FONT="] [/FONT] [FONT="]If you feel up to doing industrial quality surface preparation, this is the absolute best etching method: [/FONT] [FONT="]Chromic acid cleaning solution:[/FONT] [FONT="]10 parts/wt. Sodium Dichromate. [/FONT] [FONT="]30 parts/wt. 96% Sulfuric Acid. [/FONT] [FONT="]100 parts/wt. distilled water.[/FONT] [FONT="](Dissolve the dichromate in the water, then add sulfuric acid slowly, stirring carefully.)[/FONT] This is nasty stuff, and will etch skin and clothing with equal ease. Be very careful around it if you choose to use it. Fly safe, MalcolmW [FONT="] [/FONT] PS: When working with chromic acid or Iridite solutions, wear nitrile rubber gloves (Harbor Freight – low cost). Also a long apron and shop face shield – safety first and last.