I don't think it's possible to be more careful with the canopy plexiglas than I have been. I won't go into all of the precautions I've taken; just browse back through all the entries. But even so, I ended up with a crack in the canopy this afternoon.
It's a little blurry but this is not the place I expected to get a crack. It's on the farthest aft hole on the right side line.
So what happened? I'm not really sure, but I think it has something to do with two things:
- I've been opening and closing the canopy in order to fit the latch lugs. There's a lot of twist in the frame and canopy as you open and close it, even if you install -- as I have -- the canopy reinforcement kit.
- When I put the canopy on, I didn't put all the screws in on the side. I put one in ever four or five holes. That, I'm guessing, was a mistake since with the twisting and opening and closing, it was putting pressure on a single screw instead of spreading the load across 3 or 4 more.
That's the only thing I can come up with, and I hope I'm right. If I'm not, there's a nightmare ahead.
As I've made the latch lugs fit, I realize that the gap between the canopy and the rear window is less than I'd thought. As the latch comes down, since it's moving from front to back, it pulls the canopy down and slightly aft -- but just a bit. This actually was good news since I thought I'd made the gap too big down on the right side.
Instead, I had to do some more sanding today. Because of the discovery of that crack however, I didn't bother putting the canopy back on to check things. Instead, I loaded it in the car, and took it out to the hangar. In the spring, when it warms up, I'll put it back on the frame and see where we are. With any luck, the fuselage will be out at the hangar by then.
In the meantime, I've got some work to do on the canopy frame, including the gas struts, and some final painting and then riveting of the reinforcement kit.
With cold weather coming, I won't be doing much building until spring, which is just as well since I'm at the avionics/engine stage, I don't have the money, and there's a recession coming.