Had some problems with marbocote 227 (Why do I use stuff before reading the datasheet? I’m an idiot sometimes…)
Seems it can’t be used with PU or any isocyanate containing stuff.
Now I’ve got a CNC’d polystyrene mould, coated with a PU coating (no paint, more a layer of plastic).
I preferably use a semiperm, it’s faster to apply, more secure than wax. I hate PVA on polished surfaces.
A PU in mould coating is used (the HP-IMC), so hull from mould: end product. some polishing can be done, but we rather don’t.
Now the actual question: does anyone know if we can use Xtend 19MDR as a release? Already available. Didn’t find a reason why not. I guess a test is always a good idea.
(I’m currently building a solar boat, will share some more soon.
During the build I’m staying in a mobile home. It smells, it’s freezing at night, but it’s cheap, has a fridge to keep the beer cold, and it’s only 15 minutes from build site, instead of a near 2 hour drive. Trailer trash 
)