i have a ton of it laying around plenty for my transom can i sandwhich 2 1/2 sheets together hot coat it mat inbetween then putty it in my 14 johnson? going with a 25 mercury tiller... 2 layers of 1708 and a layer of 1.5 chopmat ontop. should i use pvc board for "nailers" to thru bolt the motor, smart tabs, shit like that? im concerned the h-60 might "crush" when thru bolting something or not have enough bite when screwing in stuff? your thoughts please. the wood has got to go and i need to get on this now.