Painting Over Anodized Aluminium ?

[Weyalan]

WE are in the process of replacing the old, worn-out mainsheet traveller system on Insatiable. The only peice of the system I am having to retain (because of difficulty sourcing a replacement) is the 3" x 1.5" RHS aluminium beam that supports the track where it spans the cockpit.

This beam was attached to the cockpit sole and sides of the cockpit with stainless steel brackets and while it was probably done pretty well at the time (you can still see the tell-tale yellow Duralac paint), 25 years has resulted in some significant corrosion.

I have cleaned up the corrosion as best as I can and plan to paint the beam to make it look nice and protect it a bit (plus use mylar shims in between the stainless and the beam when it goes back together). The question is whether I can paint directly over the anodising, with just a light sanding to key, or whether I need to take the anodising off prior to painting? (planning on using etch-primer, high build undercoat, topcoat).

[perchance]

Can you get it re anodised?

[Weyalan]

Well, we probably could get it re-anodised, but anodising doesn't really cover imperfections, whereas with decent high-build undercoat, you can cover over all manner of cosmetic dings and blemishes...

[GordMay]

Anodizing is the best possible surface for paint adhesion. No special primers, or anything normally associated with painting aluminum, is required. Remove any clear coating.

[magentawave]

Really? This is good news if true but how come so many freak out when I say I want to paint some black anodized window frames by telling me that an anodized surface is the WORST surface to paint? So are you saying rattle can Rustoleum metal primer followed by rattle can Rustoleum epoxy will do the job?

Originally Posted by GordMay

Anodizing is the best possible surface for paint adhesion. No special primers, or anything normally associated with painting aluminum, is required. Remove any clear coating.