Primer ?

[mightymite45]

Does bare aluminum need to be sanded before applying self etching primer?

 

[Skiffing]

FWIW [because I haven't compelted this yet] I've read that oxidation should be removed prior to primer application.

I cleaned w/ acetone then used 3M Scotch Brite on an orbital sander until aluminum was bright. This did not take much time at all.

Then I used Rustoleum Pintura Base self etching primer.

The directions for the paint say to degrease and use 400 grit wet/dry.

I'm going to post pics in my restoration thread later this week [2000 Monark]

 

[Johnny]

I would follow the manufacture's recommendations on the can that you buy.

ummmmmm, IMO, down to 400 grit is a bit too smooth.
I would try to get more "tooth" on the surface. More like 220 grit.

 

[bonz_d]

Scotchbrite pad then was it down with 50/50 vinegar and water.

 

[kstrayhorn]

Aluminum requires a zinc chromate primer to properly adhere. To sand, we use 180, 220, and 320 in the body shop. Oxidation will have to be removed prior to priming. A high pressure blower should be enough to clean dust off, but if you feel like it needs to be wiped down, use acetone then make sure it's dry. Vinegar can have other additives that can affect the paint.

 

[ccm]

Scotchbrite pad then was it down with 50/50 vinegar and water.

I did a very similar method to my boat. Cleaned the hull with Scotchbrite pad & dawn dish soap to remove any grease/oil, rinsed off & dry, wiped the entire hull with vinegar & then I washed & dried the boat one last time before using the self etching primer. I painted the boat in October & so far no paint has peeled or flaked of yet. I painted directly over the primer so only time will tell if I did things right.