SpudFiles

Hey,
I just finished my first gun (which I finally got in working order) and painted it using Krylon interior/exterior spray paint (it said it was approved for plastics). Basically being a total n00b at this sort of stuff, my friend and I thought it best to glue most of the parts together with PVC cement before painting because we were worried that the paint could mess with the PVC primer and cement. It looks pretty nice now, but we encountered a small setback. In areas where PVC primer (with dye) and cement were applied, the paint did not stick very well. We were using different colors, so we had to use artist's tape to cover off certain sections. When we took the artists tape off the chamber, some of the paint came off around the edges. Does anyone have any advice as to how to prevent this in the future? Is it save to apply primer/cement to painted pipe (I know this will probably mess up the paint, but will it prevent impair the strength of the solvent weld)?

Well, you should always, always prime and cement your pipe before painting it. If you get a little in an area that you're going to paint, don't wory about it, get a medium to fine grit sandpaper and sand it off that area.

After you prime and glue, use a can of PVC Cleaner, and clean off the primer stains.

Then the paint should stick just fine, paint the entire thing in your base color, then mask the parts off that you want to actually be that color and paint the secondary colors after the base color has had a day or two to cure and dry without anyone touching it.

Then spray on a few light layers of clearcoat.

Edit: Use clear primer?

Be sure to paint in the order of brightest color to darkest color, otherwise your paint will look bad.

Modder, PVC cleaner won't clean off primer stains, because the primer soaks into the pipe.

I just build the gun, then tape off any part that I don't want painted, then paint it. Use Krylon Fusion spray paint, it's great for PVC.

If all else fails use primer first, primer sticks to everything and it also opens up the door for different types of paint because basically everything sticks to primer. And if possible use a heat gun in between layers of painting, it speeds up the curing process and just makes your life easier

just a suggestion, but what about taping a few inches onto each end of the pipe, painting it, removing the tape, and then applying primer and cement to the unpainted area and building the cannon?