Painting Resin. Not sure if this goes here

During the process of making a resin piece, a mold release agent is applied so that the newly made piece can be removed easily from the mold.  Residual mold release agent is the most likely cause of your painting problems.  Resin needs to be thoroughly cleaned before painting.  There are chemicals out there designed for cleaning resin but I also use plain dishwashing soup and a toothbrush. 

Clean up that resin and your paint should adhere just fine.

-Jesse

You should wash the parts in detergent before painting or priming. I usually use a degreaser like Simple Green or Super Clean on resin. You could probably get away with a dish soap or something like that, but since you have to strip that primer off anyway, you might as well go with one of those degreasers.

so dish soap?  I tried using shampoo, I'm guessing that was a waste of time? even though I found out, shampoo is an amazing paint remover

Remember the old jingle: "Dawn cuts grease out of your way" ????

I use Dawn to clean my resin and I've never had a paint problem.

-Jesse

Thanks, how long should it soak for, its been soaking for the majority of the day.

I don't usually soak in detergent, like Dawn. When I use the dish soap, I put some on the part and use a little water and an old toothbrush to scrub. Seems to work well for me.