On Mar 16, 5:31*am, Bruce wrote:
On Tue, 16 Mar 2010 01:35:54 -0700 (PDT), wrote:
On Mar 14, 12:31*pm, Paul Oman wrote:
wrote:
Two questions for people with knowledge or experience with the UV
curing polyester resins:

1) Are they (any of them) compatible with polystyrene foam?

*2) Once the UV light has initiated the polymerization, will it spread
* * * through the layup even into places where the light did not
* * * penetrate? *I'm thinking, for instance about the underside
* * * of carbon fiber cloth.

*Thanks.


it makes more sense to use thermo set epoxies. Stronger, better bond,
probably cheaper.
epoxies will not dissolve foam

Thermo set meaning that they don't begin to cure until they are
heated?
I ask because I am looking for a very long working time.

If so, do you have a recommendation?

Otherwise, can you answer the first question? *I was quite aware of
the
other issues.

I believe that any of the polymer based resins will destroy
polystyrene foam. ...

Yes, that is correct.


By the way, UV curing polyester is not essentially a different resin.
It is polyester resin with a UV catalyst added to it and it is the
resin that attacks the foam.

Good to know.


I'm not a board builder but I believe that the polyester boards are
made using polyurethane foam.

It is quite correct that polyester and epoxy resins, mineral spirits,
gasoline and
various other solvents do not attack urethane foams the way they do
styrene
foams.

Some epoxies (e.g. WEST system) attack polystyrene. Most do not.


Have a look athttp://www.compositesworld.com/articles/techonologies-for-uv-curing-o...

for more details of using UV polyester


Thanks, that answers my question.


What are you building?


I'm working on plans for a glider. I'm interested in a long working
time.