Hey all,

I have been using EG160 tooling gel coat for my moulds backed up with carbon fibre and EL160 for items being made with ooa prepreg.

On a couple of occasions after the first attempt at making a part and after the heat cycle I have noticed hairline cracking in the gelcoat (see attached picture).

Note: I have only ever seen this after the heat cycle and releasing the part. Before the heat cycle everything is fine. 

Any ideas?