Talk Composites - The Forum for Advanced Composites

Polyester and Epoxy resins

http://www.talkcomposites.com/Topic3254.aspx

By Dennis G - 11/5/2012 6:54:39 PM

When making a mold. if I use a 80g Emulsion Bound CSM as a sealer layer after Gel Coat which needs a polyester resin can I then use 300g Powder Bound CSM with Epoxy Resin for all the remaining layers of the mold? I realize that I can use polyester resin on the powder bound CSM but I would rather use Epoxy even though it is more expensive.

One of the reasons I would like to use epoxy resin is the plug I am building is made out of foam board from the local home depot and I have read that you can seal it with an epoxy resin and not a polyester resin. Does anyone know if this is true? I do know you can't do it with the polyester resin for a fact. I tried it and it ate the foam just like they said it would.

I guess that brings up another question.....Can you put CSM with polyester resin ontop of epoxy resin?

Thanks,

   Dennis G 
By fgayford - 11/9/2012 11:55:58 PM

I put the wax on as a guarented barrier. I could also release the foam plug a bit better. But it still sticks real good.

If you want a pro plug you have to go with a hard surface. (in my opinion) You want to treat it like a car body job. The shape has to be perfect but the finish doesn't. Because to get a glass like shiney mold you have to wet sand and polish anyway. A gallon of bondo is less than $20 bucks and goes a long way. Then primer surfacer/ spot putty/ primer surfacer again. Board wet sand/ polish etc make mold.

Fred