Can I use silicone sray as a mould release?
Is it a purpose made release agent, or is this silicone lubricant? Try to use the right stuff.
I haven’t bought it yet but I have seen it around! So if I get the right stuff it will work fine?
I would definately not recommend silicone spray. If you ever try to paint a part, you are in trouble.
Either get a can of “release-ease” or use a proper mould release. There are no shortcuts.
x2. The best thing you can do is wax your mold, then spray PVA on it through a spray gun. You can get a mini compressor and mini touch up gun for less than $100 at harbor freight. I personally love the $15 mini purple touch up gun for PVA. It shoots nice and even.
I would avoid using anything but a proper release agent, I have tried wax, PVA, hairspray but nothing beats a proper semi-permanent release agent. Try Easy-Lease from easycomposites, it works great and does not need a separate sealer so works out very reasonable(though I think you could get it cheaper if you could identify the product because it seems they just re-bottle it… anyone know of a semi-perm that doesn’t need a separate sealer? )
I like the ones with sealer. The sealer usually is of a vastly different chemical base, and they act as an “insurance policy” if something goes haywire with the release. Also they are good friends with porous molds.
As for sealer-less semiperms: There are so many different manufacturers, it could be anything. Perhaps something from Acmos?
Hysol’s (Henkel?) Frekot is popular. Some you don’t need a sealer…it depends on your mold mostly, not the release. Some ppl here use wax, then Frekot. Maybe just to be SURE 
Wax might also fill in any imperfections.
Silicon and Teflon sprays can leave themselves on the part, which can cause troubles if bonding/painting.
A common solution here for plugs is to apply Ferrokote FS10 sealer, then Meguiar M87 paste wax.
The sealer takes care of porosity, the M87 is a release that does not cause fisheying of the gelcoat.
I agree with Herman on that one… paint will never stick to the part. I have even used NC770 and had issues getting paint to not “fish eye.”
Semi permanenent mold releases work excellent if used correctly to the directions. but like i said above getting the silicone cleaned off the part is difficult so paint will adhere. Possibly wipe the part down with a strong clean solvent prior to cleaning for painting.
It actually sounds like I can use a sealer on my molds prior to wax release. Lately it seems every mold i have gets damaged by a part sticking in a tiny spot, then it rips the gel coat from the mold in that spot. Sooooo frustrating. I even wax my molds 10 to 15 times prior to lay up.
I used Chemelease 15 Sealer first as application instructions, then Chemelease One FS Semi-permanent release, then wax 3-5 times with #88 or #8. With no problems parts pull from my molds with no effort or force at all.