Tooling for prepreg

I have been in the composites business for a long time. Always open mold, 10% chopper (mostly bulking molds) 90% hand lay. I have been playing with some prepreg and that’s the direction I want to go. I don’t think my VE molds will withstand the 250 degF cycle too many times. My parts are fairly large. I contract make boat parts like consoles and car body parts like hoods and fenders all the way up to pieces the size of a half of a car.

What are my mold making/tooling choices for prepreg that will last at least 30-40 pulls but would like more? The only one I have looked at was Freeman high temp epoxy surface coat and epoxy high temp laminating resin. Both are good to about 300 degF. But 5 times the cost of my current VE solution. Maybe it’s 5 times better, I don’t know. But I’d certainly like to at least consider what’s out there.


Generally speaking if you want to cure parts in specified temp the proper way is to use low temp curing prepregs like Delta Preg TR33 , cure them on stable master model till 60C. Then demold and process curing at higher temp out of the master model.In this case you need to have autoclave but do not need to have high temp resistance master model what is usually one of the most demanding thing.

To cut the corner usually do not pay-offs.

You can use Renshape 5060 epoxy tooling board, 140 C / 284 F temp resistance.
But tooling boards are costly and little bit brittle from the nature so you need to be careful during demolding.

I recommend you to change your prepreg systems for manufacturing parts into some that can be used in 80 C instead of 120 C. The easiest way and without special costs.

Thank you for the reply. My supplier only has 250 DegF and 350 DegF prepreg. What is a US source for 80 C prepreg? Thanks for your time.

We ( are able to supply 90C curing prepregs. We are not based, but regularly ship there.