Bringing up the rear

I have acquired a heavy cold. Not that this would be of much interest to cockpit builders or indeed posterity, but I thought it was worth mentioning since, once again, I didn’t get a great deal done today. What I did get done was the rear bulkhead (read: wall) which gives me two completed and skinned sides. I had hoped to get the side door done too, but I ran out of energy and the will to cut plywood mid-afternoon.

The day began early enough, waiting for a delivery from Wickes of some more 6mm plywood sheets. Since almost all the interior skin and non-backlit panel surface will be composed of this, I needed a fair bit more, so I ordered 10 0.6 x 1.2m sheets. Just as well, as I ran out of plywood for the rear bulkhead due to mucking up the cutting of one panel. The new wood duly rocked up at about 2pm.

In theory, the bulkhead is a simple structure. Unlike a ‘proper’ bulkhead it won’t have to take any load, so it doesn’t have to be mega-stiff. In the end I settled for a simple frame in 4 parts. Two straight batons, and then baton pieces mounted along the inside edge of the main A-frame at the back. The wall is toed in a few mm so as to overlap with some of the more gnarly bits of ceiling fixture, and this improves the look tremendously.

The frame for the rear bulkhead in place

The process was fairly simple, but labour intensive. Measure widths at key points, and using this, draw out the correct shapes onto plywood board for cutting; then cut using the Dremel circular saw (whose blade, I think, is becoming blunt – it’s sticking a lot, and cutting only 4mm or so in many paces such that I have to snap the cut pieces apart, and then sand away the edge imperfections). The left hand side was complicated because the bottom edge is a curve, not a straight line, so I had to approximate it with a denser set of measurements. In the end, the cuts were generally pretty good, leaving only small gaps that will be amenable to filling.

The middle section in place

Then put the panel in place on the frame – in most cases the fit was tight enough that it would stay up there without clamps, other than the very first middle lower panel – and go around the edge, counter-sinking holes for the 9mm screws. Then follow up with the screwdriver, push in the screws, and make sure the panel was flush. I had to put a cross-beam behind the middle panel to get the skin flush, but the sides went in nicely without one.

Two thirds of the rear bulkhead complete

And that is job done. It was really only a morning’s worth of work, but with my streaming cold interrupting me all day it was about as much as I could get done. Tomorrow, hopefully, I’ll do the door, which will enclose the build on three sides; and then it’s onto the footwells and MIP framing, finally.

The completed rear bulkhead

It’s starting to look fit for purpose, now, I think. A few more days and you’ll really be able to tell what it is just by looking.