Modeler Arved Grass elaborates:
How to paint brass? Here's what works for me:
- Disassemble model. Be sure any drivetrain parts (motor, gears, universals) are segregated away from the parts to be painted. Take lots of photos to document what goes where. Especially screws.
- Grit blast. I've been using 270 grit Aluminum oxide in a Paasche LAC$3 in an old Harbor Freight grit blasting cabinet. Many have suggested I go to 400 grit.
- Scrub clean with an old soft toothbrush and a good degreaser. Simple Green, Dawn Dish Soap... It really doesn't matter. Rinse.
- Rinse in ultrasonic cleaner with distilled water.
- Final rinse in 90% IPA. It will dry pretty fast. From now until the final coat of paint dries, model is handled with exam gloves.
- Prime. I've been airbrushing Floquil Zinc Chromate primer. Since that's no longer available, I'm switching to SEM self etching primer. If you held a gun to my head and told me I had to use a "paint bomb," I'd use Tamiya primer.
- I prefer Scalecoat paint on brass. Thankfully I have a stash. Rumor is it's no longer being produced. Get it while you can from dealers with stock (can't help you there - sorry).
- Mask with Tamiya and Frog painter's tape. The two seem to be identical. Tamiya comes in small strips handy for edge masking, curves, etc. The Frog tape covers larger areas, or can be cut into smaller bits.
- Scalecoat dries glossy, so no clear gloss is required before decaling, but a coat of gloss over the decals will help hide the edges. Do the gloss before your final coat of dull or semi-gloss. Reassemble model in reverse order of disassembly. Refer to the photos you took earlier. test drive to ensure everything is assembled and aligned correctly during assembly. Ditto coupler height. Isolate motor and add DCC/Sound/lighting as desired. during reassembly after mechanism is proven to work smoothly on DC. DCC will never fix a running issue. Now you know why the custom painters charge so much.