The first layer of stripping inside is 4mm, super thin, marine plywood. Using thin ply allows me to strip in large pieces, which helps to even out any of the inconsistencies in the internal framing. Larger pieces also reduces the need to do big sanding. which is an extra blessing when we are on the inside of the boat, where the belt sander is almost useless.
First layer is not strong at all. I expect I will be 3 layers in before I start to see the interior feel anything but flimsy. After 3 layers on midship I’ll start the interior fore and aft, then work on thicker strips throughout the interior to bind everything together and make her strong.
You can see the gapping in the first layer panels, especially at the top. The 4mm plywood is soo thin, its is warping as I am putting it up. Layer 2 will smooth out the flex quite a bit.