Builders' Forum Archives
Re: plywood surfboard
Posted by Laszlo on Oct 31, 2006
Sounds sort of like the construction of the San O' paddleboard series.
If I was doing it, I'd make it a little differently than you describe. I'd use 3 mm wood for the skin and horizontal ribs and go to a 12 inch spacing. Then for the longitudinal bracing I'd use a pair of 6 mm stringers that ran the length of the board. The stringers and ribs would be interlocking and all joints taped. The gaps I'd fill with USCG approved 2 part polyurethane structural expanding foam. That stuff is only 2 lbs per cubic foot and strong enough in compression that you'd be able to tap dance on the surfbard when it's done. Finally, I'd use 6" 6 oz biaxial tape to hold the top & bottom together from the outside, then cover the whole thing with 4 oz glass. With this design the outer glass is for abrasion resistance - the structural support is provided by the foam and biax tape. This definitely stops the worries about your foot going through the wood and will probably end up a bit lighter than the thicker wood & glass version. But do take note, I am not a professional surfboard designer, so this suggestion is worth triple what you're paying me for it :-)
However you go, sounds like a fun project.
San O' Paddleboard
In Response to: plywood surfboard by landlocked on Oct 30, 2006