I'm planning on building a 135cm X 40cm twin tip with the following layup/ core.

epoxy topcoat
4oz glass
6oz glass
2 X 1/4" luan ply core laminated (epoxy) with 4mm concave and a little rocker.
6oz glass
40z glass
epoxy bottom coat

Questions:

1. Do I need two layers of glass to make this board strong?

2. If doing multiple glass layers, do you do both layers at the same time while the epoxy is still wet or do you let each layer dry first.

3. Inserts. I was thinking of putting t-nuts through the top layer of wood only before laminating the two cores together. This way the bottom will be nice and smooth. Do you think this would be strong enough with the glass and everything.


I'm new at this so any advice would be appreciated. I've got good woodworking skills and I can draw a decent outline but glassing is a different story and I have little experience with it.

Questions:

1. Do I need two layers of glass to make this board strong?
A. Depending on your weight and how much flex you want...
4 oz may be fine , thats what i have on a 120 cm board.
the concave will also contribute to the stiffness
definitely no more than 6oz total per side.


2. If doing multiple glass layers, do you do both layers at the same time while the epoxy is still wet or do you let each layer dry first.
A. if using multiple plys wet out each layer individually.
But apply all plys before cure.
use epoxy laminating resin.
use just enough to wet out the glass. no top coat (or hot coat)
if you want UV resistance, coat with urethane varnish or paint after the glass cures ( dont forget to rince off the epoxy blush before painting)
it will last a couple years even if you do nothing.



3. Inserts. I was thinking of putting t-nuts through the top layer of wood only before laminating the two cores together. This way the bottom will be nice and smooth. Do you think this would be strong enough with the glass and everything.
A. should work fine
though the bottom works, as well.
use a spade bit to make a shallow couterbore for the T flange
threaded inserts (threads on outside) can be installed from top or bottom.

have fun.
-bill

thanks for the advice. Should be getting started soon.

Wheres the core ?

lauan wood. 2 X 1/4 in. pieces laminated w/ epoxy w/ a little rocker and 4mm of concave