1985 Supra TS6M 351 inboard has the plywood bottom to the 3 cusions in the rear bench rotting. These get wet every time a skier enters from the swim platform. The upholstry was replaced 10 years back and appears fine. I've read about the need to use SS staples. What type of plywood should be used to replace the rotted. Pressure treated? Exterior grade? Does it need to be sealed or glassed? Thanks in advance.
