Hi all,

Im still having some problems with the xpreg in gelcoat moulds. When i use aluminium moulds all is good. When i use the high temp gelcoat moulds i always get a dry finish on the mould side. I tried some longer times and diffrent temperatures but i keep getting these results. I only use breather underneath the mould but that always worked for me and only the bag where it it packed in to press on the carbon. Does anyone have a clue what could be it or what i can try?

The only time I'd use non-perforated release film with pre-preg is in an autoclave - and there the rules regarding air are very different!  You need some way for air and volatile moisture to escape during the cook.  If you're worried about excess resin bleed, you can get a P31 or even P6 release film with holes on wider centers.

You could also try a quick hot debulk when you debulk your first ply into the mold.  Evan a minute of heat gunning with a hair dryer will hive the resin a little flow and may help you get a nicer surface without the pin holes.