I've found that the "hobby grade" (read 5 min. , and 30 min.) epoxies do not work well due to the fact that they are too thick, and set up too fast to wet out completely.
What works great (for me) is polyester resin. (typically found in auto supply stores with the bondo, or home depot near the glues and paint brushes.)
You must pay close attention when mixing it, as it will not harden correctly if over/under mixed. once mixed correctly, it will give 15 minutes or so of "good" working time, and will be thin enough to wet out the glass completely. then it will take 24 hours to harden completely, leaving a rock hard strong lamination with little excess material.
I have also found that the 30 min epoxy sometimes stays slightly flexible, and with carbon, or glass, it completely defeats the purpose.