Painting my own resin casts

[NOBLNG]

I have  copied some wheels, engines, transmissions and miscellaneous parts with Smooth Cast 305 and 321. I intend to use Tamiya primer and likely their  LP line of laquer paints on most parts. Is scrubbing the parts with comet and then washing with dawn sufficient for cleaning them? More importantly I guess is how soon can this be done after pulling the parts out of the mold?

Thanks, Greg.

Edited March 10, 2021 by NOBLNG

[Mark]

As long as the parts have cooled (thicker/larger ones generate heat during the curing process) and are fully cured, prep and paint any time you like.

If you use mold release on your molds, you have to make sure no trace of it remains on your parts.  Once that is cleaned off, the parts are ready to work with.

[Ace-Garageguy]

Kinda depends on the specific mold release you use, too.

Anything containing silicone has the potential to play bloody herro with fisheyes and coatings pulling away from edges, or later peeling.

Most modern "professional grade" mold releases do NOT contain silicone, but lotsa modelers are notorious for being cheap and not bothering to read instructions. Vaseline, PAM, and other magic concoctions should come off with hot water, Comet, and Dawn...but don't commit to painting an entire batch until you TEST first.

The good news is that 70% isopropyl alcohol has effectively removed every type of surface contamination I've used it on...even silicone.

[stinkybritches]

53 minutes ago, Ace-Garageguy said:

 

The good news is that 70% isopropyl alcohol has effectively removed every type of surface contamination I've used it on...even silicone.

I 2nd this. I work for a silicone elastomers company and we use 91%-99% IPA to clean up our workbenches. 

[NOBLNG]

Thanks Guys. I haven’t primed any of the bodies yet. They will be well cured before I get around to them. It’s the engine and driveline parts I need soon.