Making a fibreglass reverse mould.

[spreadease]

Evening all, just I'd pick your brains and see if anyone has tips on making a fibreglass reverse mould. I have made many reverse moulds out of plaster but want a mould to be more robust and be able to make many casts from them. I have subbed out the work before for making fibreglass moulds but to keep costs down and I fancy a go, I want to know the dos and donts. Cheers

 

[kgreigh]

@Fibrehand7 @mikeadams1985

 

[mikeadams1985]

Practice on something smaller before attempting a full mould.
Run a model.
Shellac and wax it.several times.
Paint on a layer of gel coat. Leave to set then layer it up with matt and resign.

 

[spreadease]

Practice on something smaller before attempting a full mould.
Run a model.
Shellac and wax it.several times.
Paint on a layer of gel coat. Leave to set then layer it up with matt and resign.

Thanks for the quick response! that's the system I was going to adopt might practice on a simple ceiling rose then hit the 3 meter length. I find I can turn out a cast quicker in a fibreglass mould rather than a plaster reverse. Would you recommend a wax? and several coats? Buffing in between.

 

[mikeadams1985]

Wax and buff several times. The more you do the better the mould will come out and easier.

 

[spreadease]

Cheers for that, il keep that in mind!