I built the strong back out of some 2×12’s and luan plywood I had laying around. I glued and screwed the plywood on to make a stressed skin box and I didn’t notice any sag when I picked one end up.

The legs are just long enough that I can store the remainder of my plywood underneath. The angle iron and casters are actually for moving my 2500 pound lathe. But since I don’t foresee needing to move it, they can stay on the strong back for a year or so.

Next I fastened down 2×4’s and chunks of the shipping crate my plywood came in to support the bottom panel. I made no special effort to make sure the strong back was square, flat, or level so I used a laser level and sharpied a waterline on the OSB panels. From that I could measure up to where the plans called for and trim off the excess. Plus I can always make sure the boat is level by checking the waterline with the level again.

With the supports trimmed I glued and screwed the spine and first two bulkheads.

The third bulkhead is glued in and I set up some of the others for motivation. I decided not to make my own hatches with a groove and surgical tubing so I cut off the lip to fit a 13″x23″ hatch.

I planed the bottom on an angle, but bulkhead #7 still needed some help to stay plumb while the epoxy set.

I spent two weeks of lunches building the box for the main mast. The plans don’t call for it, but I glassed the inside cause why not. There’s a piece of 5/8″ OD fiberglass tubing sticking out the bottom that will drain any rainwater or spray that gets in.

Somehow the hole for my access hatch got a little too big so I cut a ton of kerfs in a strip of ply and epoxied it in place. Later I cleaned the inside up with a flap wheel in a die grinder.

Mast box ready to go in.