Pinholes/Painting

[TerryWighs]

I have read the threads regarding pinholes after painting, and all seem to be related to glass work. I just finished painting the vertical stabilizer, and see several pinholes on the aluminum. Not on the primer paint....but these showed up with the Acryglo paint I used. I can see the primer color in the pinholes???
What are the possibilities, and what is the best way to deal with this to redo???

[Kyle Boatright]

Without a picture, it is hard to tell, but it sounds like you have fisheyes, rather than pinholes.

A fisheye is where oil, silicone, or some other substance contaminated the surface, causing problems with the paint's surface tension and causing a semi-transparent circle in the paint. A pinhole is a tiny little sub-surface bubble.

There are fisheye eliminators that can be added to paint, but the best solution is to make sure your surfaces are very, very clean.

Did you wipe down the surfaces with FinalKleen (sp?) or some similar solvent based oil and wax remover before shooting the finish coat? Any auto body supply store will carry this type product.

[RV7Guy]

As Kyle noted, these are fisheyes and can only be prevented with thorough cleaning. Just before spraying wipe down with the appropriate recommended cleaner for the paint you are using, then lightly tack cloth and spray immediately.

Unfortunately, what ever contaminated the paint was probably on the metal and bled through the primer causing the fisheye. You may be okay with them. In bad cases I've seen the paint let loose there with time.

I'm going to make an assumption that you are using single stage paint. You could always wet sand and reshoot.

[TerryWighs]

Thanks guys....will wet sand and reshoot. Yes, it is a one stage paint. I will try to clean better next piece...

[N674P]

Make sure you have clean, dry air! Use a good oil and water seperator, and after that use a new hose and use it exclusively for painting. Using a contaminated hose will cause you grief...

[szicree]

I never paint or prime anything without a little disposable filter screwed into the gun inlet.