After six hours in the July heat, the layups I did this morning were cured. To my great relief, I was able to pop the fiberglass skirt off the fuselage without any trouble.
Below is a picture of the result. The ragged edges are expected and normal, but note how flexible the thing is and how pronounced the previously mentioned ripples are – not good. I obviously didn't make it thick enough. In fact the only part of it that's sufficiently rigid is the area at the top where it's six plies thick instead of only three.
I could put it back on and lay up more glass over the top of it, but I'm not happy with the shape either. So, into the trash it goes:
After removing all the tape, the canopy is back to its previous state with no harm done. That's one nice thing about fiberglass, I guess – it gives you lots of chances to get it right if you care to put in the effort.
I decided that it was dumb to have these 1/8" spacers under the rear anchor blocks while trying to mold a fiberglass canopy skirt on the fuselage. It makes sense to have them there to add some extra preload when bending up metal skirts, but with fiberglass the end product is exactly the shape that you molded it to be – if you mold it with the canopy not in its normal position, it won't fit when you take the spacers away. So, I removed the spacers and will mold the next attempt a fiberglass aft skirt with the canopy latched in its proper position. That will reduce the amount of "ski jump" effect, at the very least.
To reduce the ripple effect, I'm planning to use stronger tape – maybe duct tape for a base with packing tape on top to act as a parting surface – and do a better job of stretching it taut when sticking it down. In fact I may block the canopy open a tiny bit, put down the tape, and then latch it shut – thus tightening the tape like a drum. A straighter surface will mean less filler and less weight.
Finally, I'll use four or five plies of 9-oz cloth everywhere. That should make it strong enough. Of course since I'm almost out of cloth I'll have to wait till my next Aircraft Spruce order comes in.
Summary of today's work: A lot of glue and fury, signifying nothing. But I learned what it will take to do the job right on the second try.