West system and glass?

[Trecksail]

Hey again everyone,

This is a "discussion" I've had with a few different yard guys. It seems West (or Gougon) stresses using their epoxy only with their "epiglass" or whatever. They say West epoxy doesn't bind with regular glass. I've done samples on old plywood with different types of glass and West and can tell no difference. All are as hard as steel. I talked to "Mas Epoxies" at the Strictly sail show and they agree that the "epoxy not binding regular glass" is bunk. Of course they are the competetors.

Has anyone done simular experiments or actual repairs with such?
Any strong beliefs one way or the other?

[Rachel]

I've never used Epiglass, and I've seen lots of yard repairs that don't use it - but are using WEST resin, and have not seen a problem that would suggest use of "wrong" glass.

I've no doubt their glass is good, but I don't think you need it to use WEST resin.

There are/were mat products that used certain binders that didn't work well with epoxy, but now, for example, stitched mat products eliminate that problem.

Rachel

[Tim]

It seems West (or Gougon) stresses using their epoxy only with their "epiglass" or whatever. They say West epoxy doesn't bind with regular glass.

No, those statements are incorrect, or at least misconstrued.

To illustrate, not that it's even necessary but proof is proof, I just browsed very quickly through the West System "bible", the text The Gougeon Brothers on Boat Construction, 5th Edition, and not only did the section I browsed not even mention Episize by name or inference, but was notable in its lack of any admonition that anyone might construe as such. I have never seen such a statement in any of West System's reference products, not that I have looked specifically.

In fact, the name Episize doesn't even appear in the index of that book, nor in Chapter 13, Synthetic Fibers and West System Epoxy, which is perhaps the most immediately relevant of the book's writings on the subject of fiberglass reinforcements.

The Episize line is quite limited in its scope, with a carbon tape and biaxial cloth and tape--a useful line, but far from all-encompassing. Many epoxy laminates out there are being built using West System resins with Kevlar, Carbon Fiber, S-glass, E-glass from many other manufacturers, and numerous other reinforcement materials that West System doesn't even offer.

West System would surely like it if everyone chose to use their own branded reinforcements and fillers, but they certainly to not require it or even go so far as to suggest that somehow it is beneficial.

Old-fashioned chopped-strand mat contained a binder (glue) that was styrene-soluble, and which epoxy resin wouldn't dissolve in the same way. This might be perhaps the only shred of truth in the statements that epoxy resin isn't suitable for use with one specific material. This sure doesn't apply to other reinforcements, and most anyone using epoxy resin isn't going to be using CSM anyway, as it has few desirable properties for the modern repair or building yard--even though CSM now often is compatible with epoxy.

[David]

Needless to say: choose another yard for your boat.