IDK how you can coat at 70F.
I am thinking that has been my problem with coating all along. Now the gelatin itself is around 100F. It's heated in a kitchen shot glass that has a thick glass base that stays nice and warm for several minutes after taking out of the water bath. But the support and the glass I am coating on is room temp.

The way I see it, the gelatin has got to be very fluid if it is going to flow into the micropores in the PET and grab onto it. Once the warm gelatin is poured onto the cooler base it would seem to me that a thin, high viscosity layer would form where the gelatin contacts the support and that would give poor adhesion. Make sense?

I've tried heat up the workshop/darkroom to a proper coating temp but cannot get above above 75 F or so unless I would start a bonfire. The support is taped to a 1/4" thick piece of glass. Can I heat that up with a hair dryer or something? Would that work? What do other people do?

I think I am missing something.