Hi Everyone, my first post and my first attempt at a GRPfemale mould.

I am in the process of building a GRP model sailing yacht.  The hull is epoxiedglass cloth over a wood structure but the deck is going to be 2 layers of130gsm cloth, cast on a female mould.

The deck plug was made of wood and painted in 2-pack epoxy before waxing. It is predominantly flat but with a raised bulb at the front.   Ithought I had prepared and waxed it well but..... on removing the mould fromthe plug I have 3 issues

1.   There are a few minor voids on the flat section, I guess down tosmall air bubbles.  I assume that I can just wax these out before makingthe final casting.

2.  There are a couple of voids around the raised bulb area where I didnot get the glass flush up against the plug.   Can I get away withfilling these with thickened epoxy and rubbing smooth?

3.  There are a few small areas where the plug waxing was obviously notgood enough and some of the epoxy paint from the plug has remained bonded tothe mould.  Is there an clever way to remove these?

Or do all the above issues suggest that I should bin the mould and start again?  I only want to take a single casting from themould – so I want the least effort for a reasonable result.

Attaching photos to help understand what I mean.

Thanks in advance for your advice

Edit:-  I used no release agent - wax only

It's not that bad if you only want to make one part from it. You've given yourself some easy solutions for the first 2 issues. In fact if you've got some filleting wax and you aren't planning on vac bagging the mould, then you could get away with filling all the voids with this and shaping. Easier than sanding epoxy. 

Thanks very much for your advice.

I will see what I can do