Just following on from another post...

I have some older polyester moulds and I'd love to have a go with the EC pre-preg.  I see that this material isn't recomended for hot mouldings.  Why, what happens to it?  Is it a case of 'its OK for a quick try but constant use fooks it' or is it a case of 'just dont'?

Polyester isn't very stable dimensionally when heated so can distort a part

when bagged and under high temperatures your mould will have some deformation...delamination is also possible at temperatures to high

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

You can cook the styrene out if you post cure the moulds for about 24 hours and slowly take the temperature up to about 75 degrees C. When you use it for pre-preg you need to really make sure it is released up with a semi permanent release and dont cure over 65 degrees to try and stop not let the mould soften off or suffer from imprinting..

I have been using my polyester moulds for quite a while now with no issues... But I never go above 65 degrees...

This is out of the polyester mould..

Thanks guys.  I really appreciate the experience input