I made my first form by gluing and screwing together three layers of .75" Hardboard panels, total thickness of the form was 2.25". Yes, I now see that 2.25" is way too wide for 1.5" wide limbs ( smooth-on makes everything slippery and wood or glass slides out). I now want to make a new form out of two layers of .75" wood and would like to know what the preferred wood to use is?
I used 3/4" cabinet grade plywood.Or you can use LVL laminated beam, the stuff they use for headers over doors and windows. You can buy that in 1 1/2".
Lvl's are nice in that they are very straight and ready to go without glueing. They are typically a little thicker than 1.5"s and can be planed down to 1.5.
it is what I have used for a while before aluminum. I still use it when designing new bows.
bigJim