I'm happy using EC resin (its great) but I'm a chemist so I'm curious about resin structures and properties.  For example, does anyone know what different properties the different bis-phenols give a resin?  I'm also interested in what properties you get from different hardeners and what effect different polymer numbers have on the resins?  Links to any info would be awesome.

Thanks guys.

Havent heard of threaded epoxy, but theres a material called Twintex, which is PP interwoven with glass. Very impact resistant, very cheap. Its probably the material you think Carr made. Its a fairly thick fabric.

Prepregs do just what youre asking for though.

Yes, as a general rule of thumb, the mechanical properties of epoxies are proportional to their viscosity. The more watery the resin, the weaker it is. For example I managed to source an Epoxy with a Tg of 320C, but its so viscous, its considered a Stage B material, which means it has the viscosity of an resin  that has gelled.