attaching new epoxy to old fiberglass

george RemoveThis @w.com wrote:
> On Thu, 30 Aug 2007 14:58:13 -0700, GSS <gssmith1986 RemoveThis @yahoo.com> wrote:
>
>> Hi, I have a large sportfisher that I want close up the salon
>> windshield with a solid fiberglass panel. I was going to cover the
>> windows with plywood and then fiberglass over it. I was going to use
>> epoxy & glass versus polyester & glass. Can I connect the new epoxy
>> to the old polyester?
>
> That's actually preferred, as the epoxy will have a superior bond. make sure you
> carefully seal the plywood (especially the edges) with epoxy as well. 5 years
> from now, it will make a difference!
>

Epoxy will adhere to polyester better that polyester will adhere to
polyester. Polyester is actually quite famous for cohesive (a bond with
other polyester) bond failures.

If you are going to put the plywood in the window space and glass over
it, sealing the plywood is actually not the best idea. The epoxy and
glass bond to the plywood will be good enough to create a solid
structure and sealing the plywood will only serve to keep any moisture
that does infiltrate from escaping. Good epoxy will bond to the plywood
so well that there will not be a shear failure of the bond caused by the
changing moisture level of the core stock.

It will make the cabin spaces quite a lot darker.

Matt Colie
 >> Stay informed about: attaching new epoxy to old fiberglass 

On Aug 31, 9:40 am, Matt Colie <mattco... DeleteThis @providenospam.net> wrote:
> geo... DeleteThis @w.com wrote:
> > On Thu, 30 Aug 2007 14:58:13 -0700, GSS <gssmith1... DeleteThis @yahoo.com> wrote:
>
> >> Hi, I have a large sportfisher that I want close up the salon
> >> windshield with a solid fiberglass panel. I was going to cover the
> >> windows with plywood and then fiberglass over it. I was going to use
> >> epoxy & glass versus polyester & glass. Can I connect the new epoxy
> >> to the old polyester?
>
> > That's actually preferred, as the epoxy will have a superior bond. make sure you
> > carefully seal the plywood (especially the edges) with epoxy as well. 5 years
> > from now, it will make a difference!
>
> Epoxy will adhere to polyester better that polyester will adhere to
> polyester. Polyester is actually quite famous for cohesive (a bond with
> other polyester) bond failures.
>
> If you are going to put the plywood in the window space and glass over
> it, sealing the plywood is actually not the best idea. The epoxy and
> glass bond to the plywood will be good enough to create a solid
> structure and sealing the plywood will only serve to keep any moisture
> that does infiltrate from escaping. Good epoxy will bond to the plywood
> so well that there will not be a shear failure of the bond caused by the
> changing moisture level of the core stock.
>
> It will make the cabin spaces quite a lot darker.
>
> Matt Colie

why not use foam instead of plywood. It won't rot.
 >> Stay informed about: attaching new epoxy to old fiberglass