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?