Can you cast molds from parts already painted?

QUOTE: Originally posted by AH1Wsnake Thanks for the input, guys. BTW, HeavyArty, do you have any advice on how to cast something like water or fuel jugs that have closed handles? I was trying to think of how to do it without making a two-piece mold. Or perhaps casting the handle as a seperate part?

OK, here are the bad news.

Casting clear parts tends to require a pressure chamber as ANY bubbles in the clear resin will be visible, there are ways around it of course. Those include controlling humidity, air-pressurem slow-pouring, etc.
If you are skilled than you can do away with those issues.

2-part molds are the most common form of molds, so better get used to them and their problem areas.

Final word of warning:
Molds created of ANY master will suffer in quality/detail compared to the master.

Thanks for the input, guys.
BTW, HeavyArty, do you have any advice on how to cast something like water or fuel jugs that have closed handles? I was trying to think of how to do it without making a two-piece mold. Or perhaps casting the handle as a seperate part?

Actually, you don't need a release agent. I have made molds of many painted pieces and I never use release agents. I find it softens the detail since it takes up some of the space that the rubber should. Gently de-mold them slowly and you will have no problems.

I spray all my resin casting masters with gray enamel paint which I polish to a nice sheen. Just make sure you apply a release agent to the part before you pour your RTV rubber.