For us newcomers that doesn't have all the equipment in the world.
How do you go about sealing a fairly complicated 3D printed plug, to make a mold for resin infusion.
I am looking to use the uni-mold system but I don't have the equipment to use a spray gun and 2k primer to seal the 3D printed mold
Would it be possible to sand out the print lines of the plug and go up to something like 800-1200 grit and then do the final polish on gelcoat of the finished mold?
But how do I go about not having the plastic plug sticking to the mold?
Is easy lease enough? Maybe some wax and PVA? Will some kind do release tape work (complex shape though)? Seal the plug in epoxy? What about printing in dissolvable plastics HIPS + D-limonene, PVA and water? Print in PLA heat up finished mold in water bath or oven to 60-70C and peel the PLA from the mold? Or just say f*** it and sand the plastic down?

Have a look at a Preval sprayer system. Excellent solution for spray painting smaller objects. Even if you do decide to skip the 2k paint, you will get a much better result if you spray PVA release agent and wont have to do as much work on the mould.

There are other options that will work, like sanding the plastic smooth and spraying PVA, then refinishing the mould. Or Smooth-On 3D-XTC works ok, but isnt perfect.

Certainly if you want a professional standard part, the best way is to have a professional standard pattern - and that means painting it with 2k paints.