Difference between epoxy or poly layup?

[dirtdiver]

Does anyone have experience using both epoxy and poly. Not at the same time but on different projects. Is one easier than the other? I know epoxy cost more. Do you have to use csm with epoxy? I'm replacing the stringers floor and motor mounts on my 20ft cuddy

 

[proshadetree]

Re: Difference between epoxy or poly layup?

Both work about the same. With poly you can re-gel and better seal the floor. I do not think you can re-gel epoxy. Poly will be fine most boats are made from it anyway.

 

[Yacht Dr.]

Re: Difference between epoxy or poly layup?

IMO..epoxy is harder to do serious lams.

Low VOC resin ( VE or Poly ) is more toxic to be sure..but better working with the glass materials..

Got pics ?

YD.

 

[dirtdiver]

Re: Difference between epoxy or poly layup?

All of the pictures are in the thread in my sig. Oops put his .02 in and sides with poly as well.

 

[jonesg]

Re: Difference between epoxy or poly layup?

Oops put his .02 in and sides with poly as well.

What else do you need to know ?
Epoxy costs a LOT more, good if you want to over engineer and waste money.

 

[Peteco]

Re: Difference between epoxy or poly layup?

You can't use CSM with epoxy - the binders in it are only broken down by polyester resin.

Epoxy is good if you are going to use foam structurally - polyester has styrene in it which dissolves foam. Most people glass over plywood forms rather than foam forms/cores however.

Secondary bonds onto old polyester are better made with epoxy, although I've not heard of anyone having disbond issues with properly sanded "old" polyester.

Be aware that polyester finishing resin is "waxed", which means it contains a wax which floats to the top of the layup. You will need to properly surface prep if laying up on top of recently cured poly (i.e. sanding). With epoxy you can use peel ply, probably not compelling enough alone to justify the cost but something to be aware of if you have a ton of secondary bonds to perform.