you might try this, sand down past your mapping problems (a must.) then get some water born primer (water base) and apply a couple coats as per user instructions (nearly the same as regular primer,just different dry times). let this dry as per inst. then lightly sand and go to your color coat med wet, no epoxy. the water base primer is the last thing that will least react to your base material. the other way will be to remove all the coatings down to the plastic.
Jay D.

mini64 wrote:Dennis,
Maybe a silly question, but if I'm painting several coats over several hours, i should empty and clean my gun between every coat, right? The epoxy has an 8 hour pot life but i would think the parts in the gun internals cant sit that long without drying/clogging.

Thanks for the help! Sanded last night. Spraying this evening into the night.

I was wondering if you would be worried about that, I have left epoxy in my guns for a very long time The epoxy I use has a much longer Pot life though.

If your worried dump it in a cup run and run some thinner through the gun and let it sit with the thinner in it, I do it all the time. Then when your ready pour the thinner out & just pour your epoxy back in and squeeze trigger till thinner is gone and paint starts coming out hook up your air and spray again. remember just fog it on in super light light coats.

I like Jay's idea of using water born primer thats a good one! never thought of trying that!!!!!

Any updates???

As a side note Polyvance makes a Waterborne primer just for plastic / rubber bumpers and a special sealer all for plastic bumpers.

Their primer
https://www.polyvance.com/Waterborne-Primer-1/

Their Sealer, the sealer is a 1k product
https://www.polyvance.com/Waterborne-Sealer/

Sorry, I wanted to follow-up after i could attach a photo of the finished car. Life gets in the way.... But yes, your suggestion worked. I did four very light coats of epoxy over a roughly two plus hour period, cleaning the gun between each, and no immediate issues. I waited over night then sprayed three light coats of primer to see what would happen. waited a week and all looks good. its sanded down now, ready for base!

Glad to hear it worked out for you!
Please post pics of your finished project