Hey Guys,

We're playing around with a few moulds at home (Australia) but are having a consistent repelling issue from the Epoxy when we go to lay our carbon (240gsm 2/2 twill)
Pretty much pulling our hair out, we're convinced it may have something to do with our moulds but thought we'd seek opinion from the global community.
We're wondering if it is because of a polyester gelcoat mould vs epoxy problem? 
Anyway - here's what we have;

Mould build - the moulds always seem to be a good representation and quite solid
Release waxed mould - 5 times
Laid down polyester gelcoat (waited 24hours)
Laid down 1st lightweight fibreglass adhesion coat (waited 24hours)
Laid down 5-6 heavyweight fibreglass layers
Wait 2 days - pull mould - reverse mould looks great, detailed representation

Laying Carbon - temperature is approx 20-25C
Waxed mould - 5 times, waiting between coats
PVA release agent - light coat - wait 30 mins til applying epoxy 
Epoxy is West Systems with 205 hardener 5:1
Yet when we go to brush on epoxy it repels, ie doesn't seem to want to stick to the prepped surface

Note: when we skin items we have no issues with the epoxy

We're still noobs in this hobby, so will appreciate any input

kind regards
Justin

Hi, indeed just like a polished car bonnet in the rain by releasing your mould by the very nature of what that release is achieving is going to stop resin being able to wet out the surface and it will pool into globules! An old faded dull car bonnet will wet out in the rain no problem. Its a very annoying side effect that's for sure. 

This is the big challenge with what you're trying to do. You need to stop throwing money at large components and make a small test piece to get the process sorted. You need a method of consolidation one way or another, the fabric will never in a million years conform the that lovely shape just held down by good luck alone. Get your bagging gear out and do some tests. It won't be easy to wet lay this part and have a good surface coupled with minimal weave distortion.