Talk Composites - The Forum for Advanced Composites

Thickness and post curing of high temperature mould

By Dentex - 10/3/2020 8:43:16 PM

Hi guys,

I am almost finished with my pattern and I have ordered materials for high temperature mould that will be used for pre preg. I cannot find some answers so I hope you can help me.

First thing is, since I still don't have oven and won't finish it in next 1 or 1 and a half month, can I make mould and post cure it when I finish oven, or I need to post cure it as soon as possible?

My plan was to brush approx. 1mm of gelcoat, brush some resin afterwards and add chopped carbon on sharp angles and reinforce everything with 12 layers of 200g black stuff twill. In total, mould should have thickness around 4-5mm for each part of mould. Is that enough? I am not comfortable using thicker fabrics due to complexity of pattern.

Also, is it maybe possible to "level" some curves with mix of high temp epoxy and milled carbon fiber and pour it as next layer after gelcoat and before fabric? That would greatly reduce amount of work needed for laying fabric reinforcements.
By Dentex - 10/5/2020 10:58:41 PM

I just actually need to seal the pattern and get like from 600 to 1000 grit finish to ensure good surface that is smooth enough for mould to separate.

Finished product will be for sure top coated with UV stable varnish and polished probably so I don't need to be "mirror" after releasing from mould.