When using epoxy or polyester for molds ?

Talk Composites - The Forum for Advanced Composites

Back

Home
»
Advanced Composites Forum
»
Mould Making
»
When using epoxy or polyester for molds ?

When using epoxy or polyester for molds ?

Author	Message
Zorongo	Zorongo posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 40, Visits: 330	Hi all. I'm making small size epoxy parts, but sometimes I've made them whith polyester. Room temperature curing, hand lay up with small presure over the laminate (counter mold) I had demolding problems with a polyester mold and someone told me a "rule of thumb": Use polyester molds for polyester parts and epoxy molds for epoxy parts. (I'm actualy using PE molds for epoxy parts without any problem) So, the question is: Whe should I use epoxy molds ? An epoxy mold seems to be better fron the dimensional stability point of view.. It also seems logical to make the molld similar to the part if high temp increases are expected (prepregs, exotherms ?) to reach a similar diatation / contraction on both and avoiding stresses.... Could you please share your experience ? Thanks in advance
	Reply Like 2
Replies
baja_patient	baja_patient posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 135, Visits: 1.6K	all of the above! ^^ Rightly said, if you let all the styrene outgas from the part then it should be okay. Would I do it? no, probably not. I will use the unimold system which utilizes a vinylester gelcoat. cheers
	Reply Like 3
Zorongo	Zorongo posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 40, Visits: 330	Thanks for the answers. I didn't pay attention to the styrene matter. I've been using PE molds for Epoxy parts and normally without any problem. So I thought it was more a question of the release agent as following same process one wax gave me best results than other. I was thinking on PVA a a phisycal barrier, too.... Probabily I'll go to VE for next ones. And maybe postcuring to evaporate styrene. (And maybe also a layer of PVA "jaust in case"?) Thanks again !
	Reply Like 2