System Three puts out a fine, free, publication called "The Epoxy Book."
(You do have to register at their web site.
http://www.systemthree.com/index_2.asp

From it: (sorry about the lack of tabs)

In summary, fiberglassing is a three step process:
1. Seal the wood to prevent starving the wood/cloth joint. Do filling and
fairing on the sealed wood.
2. Stick the cloth down leaving a minimum amount of resin in the cloth.
3. Fill the weave any time after the wet cloth has reached the "green stage"
and is stuck to the substrate.

Materials Required for Fiberglassing
Epoxy resin and hardener Foam roller covers and frame
Fiberglass cloth Thalco (rubber) squeegee
Measuring device Protective gloves, dust mask
Silica Thickener Trimming knife
Microballoons Sandpaper

Appendix D
ESTIMATING USAGE
The following will serve as a guide for estimating the amount of epoxy you'll
need. The key to any estimate is a reasonably accurate idea of the surface
area involved. The numbers given are in square feet of coverage per gallon
of mixed resin and hardener except as noted. Divide by 40 to convert figures
to square meters per liter.

Coating Wood First Coat Subsequent Coats
Softwood Plywood/Veneer 250 400
Hardwood Plywood/Veneer 325 400
Vertical Surface-maximum non-sag 500 500

Fiberglassing
(sealer, wet-out & fill coats)
4 ounce cloth 150 300
6 ounce cloth 130 250
10 ounce cloth 100 170
Biaxial Tape 32 40

Roger

http://home.insightbb.com/~derbyrm

"Clark" wrote in message
.. .
How much epoxy will it take to put glass on a four by eight sheet of
plywood ? just enough for water proofing and to prevent the plywood from
checking. I have never fiberglassed anything before.