Practically Classics Forum

spraying some cellulose primer and im getting black specks ,as I spray ,got inline filter ,filtered the primer into the gun .
checked the paint inside the gun cup and you can see black film ,which goes when I shake the gun

My thoughts (for what they're worth) are that it looks to me like black pigment in the paint, I suspect that more thorough mixing before you spray would sort it out. Maybe the paint has been sitting around for a long time, or it wasn't mixed thoroughly at the factory, either way you need to stir/mix very thoroughly before using - all cellulose paints will settle, and using paint that hasn't been properly mixed can cause all sorts of problems.

Primer should be stirred not shaken. You're seeing pin holes from air pockets that are trapped in the paint.