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tooling surface question for making flat carbon panels using RTM

tooling surface question for making flat carbon panels using RTM

tooling surface question for making flat carbon panels using RTM

(OP)
How can i get a smooth consistent finish on a carbon panel surface without the odd pits and squigles i get using celophane? I have also use Air Tech's Strechlon as a barrier between my bagging layer and the glass panel i use for tooling, however pulling that off the cured panel before heat curing is easier said than done.
I am about to try using some sheet rubber since it has a consistent surface finish and releases fairly easily. Any help or input is greatly appreciated!

Mike

RE: tooling surface question for making flat carbon panels using RTM

kognition (Automotive)
Have you tried PVA. Poly Vinyl Alcohol sheet? It is a little stretchier than cellophane.
B.E.

RE: tooling surface question for making flat carbon panels using RTM

(OP)
That makes perfect sense actually. I have seen PVA sheet at my local Home Depot. And the thickness i need so it wont fold over and crease on me.
Many thank yous! Sometimes i get a brain fart. : )

RE: tooling surface question for making flat carbon panels using RTM

kognition (Automotive)
The stuff you find at Home Depot is polyethylene sheet. which may work but I would not guarantee it.
 The material I am referring to is bagging film from a Fiberglass molding supply house.
B.E.

RE: tooling surface question for making flat carbon panels using RTM

The pits and squiggles (also called wormholing)that you get on the surface is due to resin shinkage during cure in a closed cavity mold. It can be addressed with high resin pressure that is maintained well past gel. Propper mold design can also prevent it. If the mold surface can move in slightly to accomodate the shrinkage and prevent cavitation in the resin you will not get pits. High resin pressure can work to accomplish this because it will actually inflate the mold slightly.

RTM has this problem while vacuum-baging does not.

RE: tooling surface question for making flat carbon panels using RTM

(OP)
Thank you both. : )

RE: tooling surface question for making flat carbon panels using RTM

(OP)
Wax paper over my thick sheet glass work table did the trick.
I was looking for a consistent surface texture. Thanks again for the suggestions!

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