Originally Posted by
Catalinaflyer
Have not used West Systems but as per someone elses comment have used Z-Poxy Finishing Resin for all my glass work for years. Nothing fancy, might on ocassion this with a tiny bit of 91% Iso then use old playing cards to squeegee it out till just the fibers are wet but no standing resin. Have never had a failure or any de-lamination using this system.
Epoxy glue "can" be used for application of fiberglass but as someone has pointed out it's not the correct tool for the job, does not sand well, does not take paint well and certainly does not hold up to UV rays if left exposed (will yellow VERY quickly and become brittle almost as fast)
That may be true for many epoxies, but not all. This is from the West Systems C&P above:
207 Special Clear Hardener was especially developed for use with West System 105 resin in coating applications where an exceptionally clear moisture-resistant natural wood finish is desired.Improved formula chemistry allows for true clear cure with same UV stability without amber tint. An ultraviolet inhibiting additive improves the resistance of a West System 105/207 mixture to sunlight but the cured epoxy surface will still require the additional protection of a quality UV-filtering varnish.
I know, the last line says to use a a UV filtering varnish for better protection but, in the 30+ years I've been involved with racing scale hydroplanes, I've never heard anyone say they had issues with West Systems epoxy. In fact, the only one I can say I've had issues with was Z-Poxy. I found it to be very brittle when used to coat a boat hull as opposed to WS. I also found WS to be easy to sand with an electric DA as well as sanding bars