Originally posted by Richard B
The only reason I can think of for using plywood is if a builder couldn't be bothered to form the plug and moulds, spend time and money... so just bodges together a cheap ply deck in a few hours - and then covers it in GRP!
Having lit the blue touch-paper, I shall now disappear for the week!
Have you any idea of the tensile strength of good quality marine ply? The ridgidity associated with thick sections? The ability to take the load of fastenings? Remember, there have been, and still are, some very substantial boats made from plywood.
Consider your wrists slapped.