Frame A complete

The next step for Frame A was installing the plywood bulkhead on the opposite side. Although this part isn’t explicitly mentioned in the plans, Janusz’s blog recommends using an 8 mm plywood sheet for this purpose, so that’s what I went with.

Marking the frame outline

The process itself was fairly straightforward. I placed the plywood sheet underneath the frame and traced the outline directly onto it. Once the lines were drawn, I cut along them using the jigsaw.

Cutting with the jigsaw

Here’s a little trick I learned when cutting corners: instead of forcing the blade to turn sharply, move it back and forth while gently applying sideways pressure. This widens the cut just enough for the blade to rotate smoothly toward the next side.

Corners - widen the cut until blade rotates to the next side

After cutting the outline, I pre-drilled all the screw holes and did a quick dry-fit.

Pre-drilling all the holes

As usual, the jigsaw didn’t produce the straightest cuts, so I reached for my rasp to remove any excess material, followed by a file to refine the edges. The key to keeping edges square and straight is to ensure the rasp or file maintains full contact with the surface — that way, you’re shaping the edge evenly rather than gouging it.

Rasp and file for straight edges

Once everything fit nicely, I moved on to glueing. I began by sanding and cleaning all contact surfaces. Then I applied a coat of clear epoxy to the frame sides and plywood knees, followed by thickened epoxy for the bonding layer. On the plywood sheet itself, I only applied clear epoxy.

With everything prepared, I carefully positioned the plywood over the frame and began fastening it. First, I tightened the screws at the corners until I saw a gentle squeeze of epoxy, then added screws at the middle of each side to distribute the pressure evenly. Finally, I went around the perimeter and secured all remaining screws.

Once the sheet was in place, I flipped the frame to deal with the excess epoxy that had squeezed through on the other side. Instead of wasting it, I used it to form neat fillets along the joint where the plywood meets the pine frame.

Everything glued

It was quite a bit of work, but everything went smoothly — a satisfying step to complete. With Frame A now finished, I’ll be moving on to Frame P next. It’s a similar design, so I’m hoping it will go a little faster this time.