The other thing I discovered is that, if the peel-ply fabric is delivered folded, then when you apply it to the wet fiberglass tape, it is just about impossible to get rid of the crease from the fold, resulting in a ridge in the cured epoxy, and more sanding. So, see if you can get the supplier to send it to you rolled.
Prepping the sole and doubler by drilling screw holes. I will be using 3/4" for the sole and 1" for the doubler. I might have gone a bit overboard on sole screws - I placed one every 100mm. And I only hit one cleat screw in the process, but that one time broke my countersink bit ;( Photo at right shows the doubler (dryfit) in place, and the spot for a non-waterproof hatch cover over the sump area.
Couldn't find ply scraps that were large enough, so I had to trek down to Crosscut and buy a sheet of 9mm. I would imagine that one 9mm backing piece would have been sufficient, but it would be really hard to add another once the sole is glued down, so I decided to laminate two 9mm pieces together.
These span the entire area inside the cleats, and as close to the hatch opening as I can get them, and still be able to install the hatch cover.
So, here is the underseat motor mount doubler - two pieces of 9mm ply (the building manual calls for an 18mm doubler).
Isn't it interesting how the straight line marked on the planks, along the back of the seat tops, looks curved. Yeah, I know why - I just think its kinda cool.