Question Corrosion on my wing

Hay Arthur;

Internet research seems to indicate that for some reason those tiny craters are caused by foaming, or air in the paint when it was applied.

Golf ball flying abilities?

Could be

S

Steve, This is a very helpful reply. When you zoom into the pic (or look closely at the wings, you see many "craters on the moon". It is like that all over the wings. It kind of looks like the Cherokee is trying to turn itself into a golf ball.
filiform corrosion is new to me. I will have to look that up. Thanks again for the reply.

Hi Arthur,

You're seeing filiform corrosion. That corrosion type is not particularly worrisome, but it's a good idea to stop it. I like your Scotchbrite idea, although I would use a few drops of paint stripper to clean and prep the surface beyond the limits of the corrosion. 
I like the Dupli Color self etching primer for sale by Aircraft Spruce and Specialty. It etches aluminum; if you find another primer that can etch aluminum that's fine. 
Primer is not a very good protective coating. 
Ideally you should spot paint the surface with a harder paint. 
I have found that an off the shelf rattle can paint in white is very close to the paint on my Comanche. 
I do not like Rust-o-leum rattle can paint. It takes forever to dry.
The key to spot painting is to pivot the can nozzle around the spot you want well covered. In other words, start spraying when the nozzle points 90 degrees away from the surface, then, holding the nozzle the same distance away from the desired coverage area, continue spraying as you smoothly and quickly rotate the nozzle 180 degrees with the aiming point in the center or the 90 degree point in the rotation.
To say it another way, the area you want covered with a smooth layer of paint is at 6 pm on a clock face; you're gonna start the spray at 3 pm and then rotate the nozzle (and the can) clockwise thru 6 and up to 9, where you stop spraying.
The undesired, less than smooth overspray can then be smoothed out with very fine sandpaper. 
The first pass should be what's called a "tack coat" a light coat--either rotate faster from 3 to 9 or start farther away.
The second coat should be "wet" but not runny. If you get good coverage on the first wet coat, that's enough. If you didn't, apply one more coat applied 90 degrees the first coat.
You will learn how to do this by practicing on a sheet of cardboard. Take your time. It's a fun job.
Are there what look like little pin holes in all the paint on your airplane?

Steve

I found some corrosion on the wing of my 1967 PA-28 180. My plan is to use some fine scotch bright on it then spray it with self etching primer. I would like to use a primer that is a little closer match to the original off white of the Cherokee. Do any of you know of a source? What do you think of my plan? Thanks