Frame C - plywood knees and epoxy

 When I started preparing the plywood knees for frame C, I was shocked to discover that my bottom pine piece was too thin! I had assumed it was the regular 55 mm width, but when I checked the shape of the bottom knees against the plans, I realised it should actually be 70 mm.

That meant an unplanned detour: cutting a new 70 mm strip and shaping it properly. Better to catch it now than later—I only lost a bit of time, and I should be able to reuse the 55 mm piece on frame D. A good reminder that the plans are there to be checked often, not assumed!

With that fixed, I went back to the plywood knees. Using the table saw, I cut strips of plywood for the bottom and upper knees.

Plywood strip for drawing knees

I’ve found that the simplest method is also the most accurate: just place the plywood strip under the pine pieces, trace their outlines in position, and cut. That way, the knee matches the actual frame, including all the inevitable small deviations from the “theoretical” plan dimensions.

Just draw the outline - quick and accurate!

This time, sawing the knees felt much more natural—I used a regular hand saw and got clean, confident cuts.

Sawing straight lines

For the trickier inside angles, I found a keyhole saw lying around the house; it was perfect for carefully steering the cut into tight corners.

Keyhole saw to change the cutting angle

Once all the knees were cut, I moved on to dry-fitting: screwing everything together, checking alignment, and preparing for the epoxy. Compared to frame B, the number of parts in frame C makes the job longer, but my past experience paid off—I worked much faster and more methodically.

Starting the dry-fitting stage

I glued in stages, tackling just a few pieces at a time. I mixed small batches of epoxy (two to three pumps per mix), since large amounts cure quickly and heat up alarmingly. With practice, I started to relax into a rhythm: spread one batch, screw the pieces together, use the squeeze-out to tidy up the previous joints, then move on to the next batch.

Glueing the upper plywood knee

After a slightly longer session than usual, I finally glued the entire first side of frame C. A lot of work, but a great step forward—almost done with this frame!

First side glued!