Given the inclement weather due to tropical storm Lee, I decided to finish up some paint tests prior to shooting what I hope will be the last day of basecoat trim.

I've been doing some reading along with the testing and they each seem to confirm eachother:

At present I have a hybrid of paint types on the model but so far I have had no issues. In a nutshell, the single stage epoxy based white basecoat went atop the prior primer coat without issue. This last primer coat acted as a barrier to the underlying high build polyester based primer which was fully cured and wet sanded for several days. The basecoat seems to be stable after several days of having shot it and wet sanded it.

Atop I laid a trim coat of what I believe to be an acrylic enamel based paint. Again, with the base primer between the base white epoxy and the red enamel, there were no issues with compatibility. I am now at the stage where I will be using acrylic lacquer and this was the type of paint I was most concerned with. After my tests I discovered the following:
[ul][*] acrylic lacquer directly over cured epoxy holds.[*] acrylic lacquer over primed cured epoxy appears to hold very well.[*] acrylic lacquer directly over cured enamel does not hold (crazing and dullness result in the metallic lacquer).[*] acrylic lacquer over primed cured enamel holds but not exceptionally well.[*] acrylic lacquer over un-primed smooth substrate does not hold very well. This is probably true of most paints.
[/ul]
I have not done any tests with the clear coat process as I am in still in the process of deciphering what exactly constitutes Dupli-Color Perfect Match clear coat. I believe it to be a single stage (well, this part is clear) acrylic enamel (unless it is a lacquer like the matching paint) and it is in theory chemical resistant. It is likely no where close in hardness and durability to a two stage (2K) acrylic urethane but if I'm unable to source the 2K Spraymax urethane I might have to go with the 1K clear from Dupli-Color. It is likely higher in VOC's (lacquers are fast drying) so it should dry to a lighter (in terms of weight) finish compared to the high solids urethane. This, in turn, means that more coats will have to be applied to produce a hard durable surface. I'm thinking that 4 coats might be a good initial coverage followed by reapplication if needed after wet sanding.

Just posting these thoughts for future reference and in case they may be of some interest to others.

Attached is also a useful PDF from Dupli-Color with various painting tips.

David.