Fun with foam

I decided that the temporary plywood forms were going to be too heavy to hang off the sides of the hull without distorting the side panels, so I made them out of 1" pink insulation foam instead.

I screwed the side panels onto the forms with drywall screws, which will come out before the outside of the hull gets glassed:

The two bulkheads need to be glassed before adding them to the assembly above. 

I decided to make my own hatch for the forward bulkhead. I noticed that the ⅜" foam with 4-oz cloth (in cured resin) on it can be curved by hand, as long as the cloth is on the outside, so I made the hatch cover with a lip:

 The sides had to be pressed in when gluing it up or they bowed out, so I made a form and lined it with plastic.

Below, the corners of the hatch cover still need to be rounded. Sandpaper works fine, but I needed a mask, which is at the shop, so will finish shaping it there:

Forward bulkhead with opening, hatch cover in background:

 How I did that: I first cut the opening in the bulkhead, then glassed one side of the bulkhead. Before the epoxy set up, I glued a rectangle of foam on top of that, trying to line it up well, as I had made the piece only ¼" or so larger on each side than the hole that it covered. After the epoxy set up, I cut the hole out of the added piece to the size of the opening, which left just a lip on top of the 4-oz glass. I did the same with the other side:

Above shows the forward face of that bulkhead, with the hatch cover on the after side of it.

The lip on both sides of the hatch opening make a frame that strengthens the bulkhead around the opening. I'll cover that frame with one or two layers of 4-oz cloth on the diagonal, with thickened epoxy in the tight corners. (The diagonal-weave cloth takes sharper corners without lifting off the work and leaving air underneath. It's also stronger, as the strands of both directions cross everywhere. And, it takes complex curves better.) The diagonal-cut cloth will wrap around the frame from one side of the bulkhead to the other.

You can see below that the hatch, although the opening is only 10½" wide and 7" high, takes up most of the area of the bulkhead. I just checked, and my tent and air mattress both fit through the opening. The sleeping bag doesn't, though, so it'll have to go in the after hatch, which will be about 12" by 14".