sorry if this has been asked before but i have searched the forum but to no avail

i,m about to make a mould using E.Cs Epoxy Mould Making Starter Kit . i will be moulding around a small polyester fibre glass plug

id like to know what steps i need to take before putting the two together

i,m ok in understanding the basics of getting the surface to an excellent finish i.e sanding,polish, compound, etc.

but unsure what i need to cover or paint the surface of the plug with prior to smoothing and polishing

i bought some rustolem plastic primer which says its good for use on polypropylene, polystyrene, resin, PVC, fibreglass and vinyl plastics.

but would it react to the epoxy mould putty

any help appreciated