I coated the finished mold halves with Aeropoxy laminating epoxy, mixed liberally with microballoons.
I mixed up a 10 gram batch of Aeropoxy into a small plastic and thoroughly stirred it with a craft stick chucked into a drill press. The process that I used was to coat the mold with a chip brush then wipe off the excess with a paper towel. I did that process about 5 times, maybe more or less. One thing I did not want to do is to glop on epoxy and leave it, since that would destroy all the work to prep the surface. I made sure that the nook and crannies were as cleaned up as possible. The idea was to let it soak in and not puddle on the surface. Then I dusted microballoons onto the mold surface and then rubbed them into the surface, followed by wiping off the residue with a cosmetic cotton pad. I repeated this activity for about 3 cycles or so. The idea was for the microballons to attach to any small wet areas and fill up these small voids, thus smoothing the surface. Hopefully the surface will be sufficiently sealed for the waxing process, but that will have to wait. That's because I have set the mold halves aside to cure for about 2 or 3 days.
Personally, I don't like this phase. It's boring, monotonous, and not enjoyable. That said, good results are always predicated on good prep work. Hopefully at the end of this process I'll have some cool looking Pat fins and have gained the experience to port them over to other projects.
If anyone has a better process than what I have outlined that has worked for you, please let me know!
Greg