Hi EZSailor,
Sorry for my delay in replying - I wrote you a whole essay in response to this question a week back but must have closed my browser without hitting 'Post reply'. The pain!
The gist of my reply was....
Firstly, temperature. Although it's not a good idea to be working at 12'C and all our cure times and performance properties (and tests) are based around 20'C. Really, you should aim for at least 18'C where you're working. I don't think the temperature caused the problems you've experienced but it's likely to cause other problems down the line so watch out and maintain a decent working temperature.
*If* you want or need to use a clear layer before your reinforcement then this clear-layer needs to be a gelcoat, not a resin. Resin will always fish-eye away from a repellent surface like wax, I would also certainly recommend you use a
Chemical Release Agent instead of wax on your flat surface; we always use Chemical Release Agent for our flat sheet production, I don't think we could make flat sheet properly without it.
You also need to consider what it is that you want to achieve with this gelcoat - is it for (1) UV stability, (2)polishability, or (3) to solve problems with 'pin holing'. If it's '1' or '2' then you would probably be better served with an
epoxy compatible polyester gelcoat like our GC50. If it's for '3' then you won't find that a gelcoat (or clear resin layer) will solve the problem of pin-holing, it will simply move the problem down below a thin layer of resin, creating unsightly trapped air bubbles instead of pin-holes. To solve '3' you need to change your lamination technique.
As for the pin-holes themselves, this really is part of a painful trial and error process that always accompanies vacuum bagging (rather than resin infusion). It's almost unheard of to be able to vacuum bag a laminate like that and get a pin-hole free perfect surface first time and more than likely, even with some playing around (vac pressure, bagging stack, resin quantities) you'll pretty much never get that perfect surface you're after. The only reliable solution (when you're wanting to produce cosmetic quality surfaces) is
resin infusion. If you've got vacuum bagging equipment then you're only a few bits and pieces away from a resin infusion setup. My advice would be to take the plunge on that.
I hope this helps and look forward to working with you some more.
--Matt
Matt StathamEasy Composites / Carbon Mods - Technical Sales