Aluminum Pitting

[LARSON69]

I'm trying to clean up and re-paint my 84' Suzuki Outboard. It's pretty corroded and I have alot of black pitting on the lower unit. Does anyone know how to remove this black stuff so that I can prime/paint? I think if I sand I'll go too deep into the metal. Can I just prime over it? Thanks

 

[Coors]

Re: Aluminum Pitting

Small sandblaster; Ospho: phosphoric acid... I used phos acid, then self etching primer ( chromate seems to have taken off the market).
Then quality OMC spray paint. Good for 2 years now, in brackish.

 

[LARSON69]

Re: Aluminum Pitting

Ok, where can I get that kind of acid?

 

[Coors]

Re: Aluminum Pitting

Ace hardware, home depot.

 

[LARSON69]

Re: Aluminum Pitting

I'll try it, thanks

 

[LARSON69]

Re: Aluminum Pitting

Ok, I tried the acid today and it removed a small amount of the black corrosion. I plan on doing it again but am wondering if it's ok to prime over these black pits if I can't remove all of them? Will self-etching primer adhere to these areas? I appreciate anyone's input on this. Thanks

 

[Coors]

Re: Aluminum Pitting

I didn't remove mine (the acid is a chemical reaction, not a cleaner) It coats against further corrosion.
I used etch, good so far in brackish.

 

[LARSON69]

Re: Aluminum Pitting

Roger that, I was hoping that was the case. I'll go ahead with the primer. Thanks Coors