This is what composite professionals are using when doing plugs or mold repairs ;DURABUILT Surface coat
You can found those materials in UK :
Durabuild Surface Coatings GlassFibre, GRP, Epoxy Resins & Hardeners, Vacuum Bagging Materials and Laminating Resins
There are 2 sort of;
1/ first one is an "heavy primer "you sue it when surfaces are to be finished roughtly and makes a good "screen " to previous mods with bondo , etc
2/ second one is a finihing liquid you can spary like a paint coat in fine lies and then you can sand fron 400 wet grit to 1000 and polish it extremly glossy
then after 3 times laying wax and polich mirror ; you will neither have any sticking to the brandnew gelcoat mold
Problem of 2K paints is ; if you do not have ventilated all from the coat surface it's areal lotery ;
One day you unmold perfect :thumbsup:
Another day ( with no reason apparently !!) you unmold with all the painted coat sticked onto the new mold gelcoat !!!!!!!!!!!!!!!:thumbsdown:
This Durabuild coat is perhaps pricy but save hundred of hours worh when this is happenning !
Yes, this does happen, I have found that you need to let the paint fully cure and this seems to stop it happening.
I have also found that on quite "tricky" parts, paint and then sand wet with 1200 grit paper, this seems to give the wax something to key to, have had good results but then you also have a satin finished part come out of the mould unless you polish up the mould afterwards with a mop.