Great, thanks for all the help everyone, the bits left behind in mine do feel more than just a film, the tiny bits pick off with your nail. I'll have another go, concentrating on by bag seal and perhaps leave it longer before de moulding.

I get the same pattern on my moulds, it's nothing to be concerned about. You don't need to wash it off, I just buff mine lightly with a clean cloth after each pull and then do one wipe with my release agent which is Frekote. This pretty much eliminates the pattern on the mould surface, and what does remain doesn't transfer to any parts. 

I've no idea why it happens, maybe where there is no resin just leaves a thin film on the mould and the fabric takes the resin with it. It normally comes out with a bit of elbow greese.

That's interesting, Im yet to have a fully airtight bag and had to leave pump running!!!. Do you know why it would cause this problem?. How do you clean your moulds when you've had this happen.

Cheers

I sometimes get left with the same pattern, but it's normally when I've had a leaky bag

I'm not sure but I mostly wait 2 days (at +25°C) but not sure if this is the cause!

Hi mattieutje65,

Been de moulding after 24hrs at around 20deg c. (ec epoxy resin) Would you advise leaving it longer?

Thanks for your help

Craig 

After how much time do you demould? might be that the resin hasn't fully cured and is still a bit 'soft'

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com