I couldn't get an exact measurement of my transom before I cut it out. It seemed to be about 2 or 2 1/8 inches. Does anyone know what the maximum thickness I could go is? Not that I plan on going much thicker but it could end up 2 1/4 or so depending on how much glass I put on. Also FWIW I have been checking prices and Poly resin costs $28 with tax here, I can order a 13 gal epoxy kit for $29.00 a gal or a 6.6 gal kit for $34 per gal so I'm going with epoxy all the way.