Why don't you send some photos. I've never tried to bend plywood, but the archives have some information. Your husband is a lucky guy.
There are 3 basic methods to bend ply: 1) soak as you did, 2) steam and 3) clamp.
1) From Poobah 2010
http://rodndtube.com/paipo/forum/viewtopic.php?t=881
I've been out of board building for about a year, and now I'm dropping back in with a poplar and pine psuedo Penzance paipo. The perimeter was pirated from an old Penzance board...a Crest model from the West Cornwall Woodwork. My Cali version of a Cornish board is made of poplar 1 x 12, rather than the marine plywood of the original.
Boil bending the nose got me very close to the 1 3/4" nose kick of the original. I got 1/8" more and I'm not done with the final sanding yet. I soaked the nose end of the board for three days in a rain barrel (nonchlorinated water.) Then boiled the nose in a large pot of regular tap water for about 30 minutes, and then clamped a curved (shaped) chunk of 2 x 6 redwood down on the top of the nose. The edge of the bottom of the nose rested on a curved chunk of 4 x 4 redwood.
2) Clamping method.
http://mypaipoboards.org/forum3/viewtop ... t=10#p2780
The French and Spanish used presses:
http://mypaipoboards.org/interviews/Mar ... soro.shtml
They glued their own ply.
3) Boiling water.
http://vintagesurfboardcollectoruk.blog ... -cope.html
The original parallel-sided boards later gave way to tapered models ( see cutting plan ), which still made 8 boards per sheet.
After cutting them out with a saw, the board`s noses were wedged into the tops of drums of boiling water for an hour : `Getting the nose kick was pretty crude, really. Bert had some long pole ladders where we would jam the hot and wet nose down under one rung, and pull down and tie the rest of the board against the ladder with rope. Just one long ladder could take a dozen or so boards tied down in a row. A day or two later they were bent for good, and dry, and could be untied and finished off.`
They didn`t use a jig or mould to get the nose kick, as these would stop air getting to the wood and drying it out. However the `ladder` method produced many different radius curves, and in different places along the boards - it all depended how much nose was jammed under the rung, and where and how tight the ropes were tied. Due to this variety people now assume many companies were making boards. No, there were only a few.
4) wikihow
https://www.wikihow.com/Make-Wood-Flexible
The shorter the board, the less need for kick.
Finishes. varnish, resin or tung or a linseed mixture are all options.
More build info here:
http://mypaipoboards.org/forum3/viewtop ... =569#p4839
https://www.surfertoday.com/bodyboardin ... aipo-board
https://www.youtube.com/watch?v=1NeNf6qrQc4
Bob