Industrial Designer from Chicago
If you post these prints online please provide a link to my website.
Feel free to send me questions or concerns but do so after reviewing my website.
Always test on scrap first
Apply Filler Primer : I use Rust-Oleum Automotive Filler and Sandable Primer.
Applying a filler primer will seal off the powdered nylon so paints won't just soak in like a sponge.
Apply Paint/Primer: I use Krylon Fusion Glossy White. I apply this for the following reasons.
White contrasts nicely with the gray filler primer which is good for sanding. Paint is thicker then primer(in this case it's a 2 in one).
The striations will still show through the gray primer. The paint will fill them in more. When you sand the first coat away you will get a surface with a mix of white and gray. The following application will be smooth.
A white surface plays well with applying additional paints. It's easier to darken white then to brighten black. You may find yourself using less coats of your final paint.
Apply Paints: Acrylic model paint is good option.
Apply Gloss: Krylon and Rost-Oleum make good ones.
Sanding : Wet Sand. I find that 400 grit is a good place to start and work your way up to 1000 or greater. The finer the sandpaper the smoother and mirror like the final finish will be.