Question for boatbuilders

[foxracing]

One for the boatbuilders, what type of ply and thickness is generally used for the decks on a c hydro? my current deck is 2mm ply but its gone all bowed and wavy so im going to redo them.

[Fastjack]

My new boat is 3 mm

[DeanFHobart]

Make sure to coat the entire underside with your epoxy. And also the top side with epoxy...If you are using the West Sysrem the 207 Hardner works the best for the seal coat. Then of course wet and dry sand it smooth and then paint or varnish. You can call the West System Technical Assistance line for help.

[ZUL8TR]

I use 3mm for deck, make sure adequate stringer support for no waves. As Dean states coat the underside, I install when underside epoxy is not set and give top side 3 coats of epoxy and 2 coats of varnish has worked well (some use auto 2 part clear). I roll (3/16" thick foam roller) and tip (foam brush) for nice spread and level coats of epoxy and varnish. I dry orbital sand epoxy with 120 and last coat 220 for varnish prep + 360 wet for 1st coat varnish then 360 wet for additional varnish coats. To remove varnish dust buggers etc after a week of cure I wet sand with 2000 then 5000 then buff with very fine polish compound. All wet sanding has some dish soap in water, helps cut better.

[baries]

I like 4 mm. The extra couple pounds are a small price to pay for the additional strength gained with the thicker wood.

[Team B&H]

There are always trade-offs in plywood thickness for decks. Decks contribute greatly to the torsional rigidity of the boat. Small boats ( J, A ) can use 3 mm because there are lower forces on them. C is kind of a mid-level where 3 mm is tolerable for a one or two year boat but if you plan on using it competitively for longer, use 4 mm. If weight is still that much of an issue, I sometimes use 4 mm for the inner decks which are more important for rigidity and 3 mm for the outer decks. Bigger than C is always 4 mm.

[Dennis Crews]

Awesome information here. Great thread. Thanks!