Niven,

I can understand why a little bigger ply and smaller gunnels would work. My gunnels were 40x20 or 1.5x.75" per Tom Yost.

: Marc I used 7mm ply which is about 5/16 with a 20x20mm gunwald and
: had no trouble but the frames were full with no hole. I was
: making a S on F using ply (dare I say it doorskin!) for the hull
: skin. I did use Okhune for the deck as I needed better
: lengthwise flexibility. I was making a design Id been playing
: with for a couple of years just to satisfy myself it was OK and
: my dreaming wasnt wasted - it turned out pretty well. Maybe
: cutting the inside hole on the frame after its in place may have
: helped? Or cutting the frame on the diagonal? Okhune was about
: $US 65 for marine 4mm here in New Zealand so $120 a sheet in the
: US sounds a bit toxic as some others others on the board seem to
: be charged.