[Goosesdad]

Release agent, Partall, brushed on (no pic), let dry...couple hours, 2 coats. Then white gelcoat, also brushed on. Lots of differing thoughts on how long to let it dry before glassing. Most will only let it dry a couple hours so it's still tacky for the best bond, I subscribe here as well. However, if the gelcoat isn't thick enough, the resin will eat it and you end up with alligators that need to be repaired later. I've done multiple funny car bodies with the gelcoat curing overnight and never had a delamination. Controlling thickness with this shortcut of brushing on the gelcoat is near impossible so letting it cure for 8 hours solves that risk, probably doesn't bond as well but since these molds aren't for commercial use, all good.
Why brush instead of spray? Less cleanup, faster but for sure will introduce small air bubbles. If this was a mold for a body panel or something that we wanted perfect gelcoat, spraying is the only way to go. I will spray the gelcoat for the actual parts, like in previous pics.

Those little bumps are just sticky back cabinet bumpers, they create alignment pins so the mold sections go back perfectly. Yep, brushing gelcoat upside down is a mess and isn't perfectly flat but for a mold that will likely make one part or even 20 parts, absolutely fine.

Done in multiple sections so it will come apart later, if it was done in one or even 2 sections, given the angles of the part, the mold could get trapped and it wouldn't release. This is the first 2 sections.