Darren,

For a given weight, either more epoxy-glass with less wood, or more wood with less epoxy-glass, you won’t realize much of a difference in strength. The lighter glass will dent easier and scratch down to the wood more easily.

If Kyle hasn’t eased your concerns about 3 mm plywood, you could glass the insides of the panels before assembly to stiffen them up.

Sam

: Hi,

: I am about to start building a Point Bennett 18 ply S&G kayak, and was keen
: to do a veneered panel pattern (similar to that shown in Wooden Boat April
: 2009 in 'Launchings' article p83).

: This will involve building the kayak from ply panels as per normal, then
: epoxying 0.6mm ply sheets to the hull before glassing the hull.

: The plans call for 4mm ply, and Duane (the designer) believes 3mm panels will
: flex too much in building. Having used 3mm, I agree.

: However, I don't want an overly heavy hull. Should I go with 3mm ply with the
: 0.6mm veneer, making a 4mm hull and something like 200gsm cloth bracing
: the hull panels during building to compensate for the thinner panels); OR
: go with the 4mm ply, adding the veneer and glue being a 5mm thick hull,
: and a lighter (125gsm) glass?

: Not sure which would give a heavier hull, and what effect thinner
: hull/heavier glass vs thicker core/lighter glass would have on overall
: weight and hull strength?

: Any thoughts, advice, etc appreciated.

: Thanks,
: Darren