I actually started using a 208 tip. I used a 210 tip for a long time, but the smaller orifice of the 208 gives me better results. The small pinholes are from spraying too thin in spots. Increase your pressure and spray the doors with a couple light and quick passes. It might look too light at first when you spray in quick passes, but the enamel lays out after a few minutes and looks thicker than when you put it on. That's what makes it tricky to work with at first. You want to spray just enough enamel so it's evenly coated. Then you won't get the pinholes anymore. You might also be spraying too far away from the surface.