My Jesse Boyce is a 28-foot L. F. Herreshoff designed wooden sailboat. She was built during the late 70ís and early 80ís. Her decks were constructed of two ľ-inch layers of, what was supposed to be ďmarine-gradeĒ plywood topped by 11/16 thick iroko deck planking, about 1.5-inches wide. After better then 25-years, the plywood sub-decking is delaminated, rotting and falling apart and obviously needs to be replaced. The current wisdom is that I remove and dispose of the decks entirely, planking and all, and replace them with a solid layer of the current quality of ďmarine-gradeĒ plywood capped with dynel and wetted out with Gluv-it epoxy.
But hereís a different plan. A bug got put in my ear yesterday and I woke up at 2:00 AM and started figuring this idea out. Instead of going through the process of laying down a plywood deck, and covering it with Dynel and Gluv-it, all the expense, likelihood of things kicking off too soon, or not kicking off at all, the inevitability that moisture is going to find its way into the wood and start the same set of issues I'm dealing with now all over again, the thought was to try "plastic plywood". The expense would be pretty much equal to the aforementioned "marine-grade" plywood treatment.
On the one hand, I could just stick to the plastic sheets. They come pre-colored, textured and with non-skid surfacing and it holds up well against UV radiation. The down-side seems to be that a 3/4-inch 4-foot by 8-foot sheet weighs about 120-pounds! And Iím looking at about 10 of them. But Jesse Boyce always did perform better with a load on her! Another is that while plastic sheeting seems to stand up very well to abusive handling, repairing any damage is going to be a bit rough.
But, on the other hand, if I was careful removing the 11/16-inch iroko deck planks, we could run them through a planer, shaving off like 1/8-inch per side to clean it up and lay it back down over the 3/4-inch thick plastic sheet. That would keep the decks at the same thickness as they are now. That would also go a long way to protect the plastic sub-decking from damage. I would never have to worry about it rotting out or moisture getting to the plywood through the iroko swelling and shrinking and cracking the seam calking.
I assume that the construction details would be the same, butt-blocking between the deck-beams, but I have no idea as to what would be the best calking / sealant to use on plastic like that. Iím also not sure of what brand or type or thickness would give me the best structural stiffness and strength to support my weight (3-4XL) between the deck beams while not going soft under the heat of the mid-summer sun. The largest spacing between deck-beams is a 14-inch gap about midships. But if I put the iroko back down, that would add to the carrying capacity of the decks too.
Sheís coming into the dock tomorrow and Iím going to turn too on finishing getting her apart. Iíve engaged the help of a carpenter friend to help and he thinks itís going to go pretty quick, so Iíve got to make some decisions here. Iíd like to have her re-decked and the cabin back on with its new top as well and all closed up before it gets too uncomfortable to work out there in the New England fall weather.
Any suggestions or thoughts would be a great help!