I would not naturally expect a place selling glass to be aware of the issues. Especially not a generic boating store like BoatUS. A specialty place is more likely to know though. Heck, worse comes to worse, find out who's glass they are selling, and contact the manufacturer yourself. Shop your prices, they vary wildly I've learned, with the chain stores being the most expensive around here.

If you've got a place that sells West system epoxies, pick up the literature they've got laying around on it. It's worth paying a little for their how too booklets. There's a wealth of info in them. It's almost all on their web pages too. Nice charts about the relative merrits of the different filling agents.

By and large, hollow spheres are for pretty. They aren't strong, but they sand nicely and are terrific for fairing. Tend to be white. The milled fibers are very strong, a bear to sand, and are often off white, but can be different depending on the fibers themselves. Very usefull for structural areas like filleting. Don't know much about the quartz, but I have seen recommendations for using similar materials for strength areas instead of milled fibers.

> Hello all!

> It's getting close to that time when I'll be needing to acquire
> the resin, cloth, and associated paraphernalia. I found a more or
> less local source for MAS epoxy, but they aren't into selling cloth.
> :-( I remember reading quite a while back that not all glass and epoxies
> are compatible, so I'm somewhat nervous about this. Is it too much
> to expect that whoever I purchase the glass from will know about this?
> Another thing, can someone - or everyone :-) please tell me the difference
> between phenolic micro-balloons, quartz micro-spheres, and CAB-O-SIL
> (and maybe milled fibre)? What are their uses and properties, ie.
> colour when wet-out, density, "sandability", strength, etc.
> Until now I hadn't really needed to know about these products, so
> it's about time I became more informed.

> Thanks in advance for any help.

> Mike Spence