Best glass cloth for epoxy?

[Zooport]

What kind of cloth works best when using epoxy resin? 

I have years of experience with polyester, but I not that confident with epoxy.  My last repair turned out pretty good, but something seemed weird with the cloth; almost like it didn't fully bond with the epoxy.  When I sanded it after curing, a bit of the fibers separated from the resin.   Maybe the guys at the supply shop gave me the wrong glass, maybe it's fine, don't know.

[Bean]

The very same e glass or s glass that you would use with polyester resin Zoo.

[RATbeachrider]

It sounds like a mixing ratio and/or curing issue(s), Zoo.

[surfcowboy]

Yeah, that's not a glass thing. If it's "surf" glass, that's pretty much it.

[PonoBill]

Epoxy generally wets out better than polyester. I have experienced something similar to what you might be describing with glass that had a lot of sizing in it. Some crap I picked up on e-bay.

[jpeter]

Sounds like the epoxy didn't fully cure fully.   Heat and time cure epoxy.   Glass will always sand fine if the epoxy is hard enough.  If you are used to polyester, you know it cures brittle hard right away.  Cure depends on what you are using for epoxy,  really look at the specs of whatever you use.
Epoxy is so much more healthy to breath in,  Poly is nasty stuff.  Wear a carbon filter mask either way. 

Using Kevlar cloth is a different story,  fibers are always stronger than the resin and pull up.

jp

[Sliver]

If you are not ordering from a standard surf supplier the style numbers listed will make sure you are getting the correct cloth:

E-Glass

Style 1522, 3.7 oz./yd.² E Glass, Plain Weave

Style 7533, 5.6 oz./yd.² E Glass, Plain Weave



S-Glass

Style 4522, 3.7 oz./yd.² S-2 Glass, Plain Weave

Style 4533, 5.6 oz./yd.² S-2 Glass, Plain Weave