Peter-
BTW, if you're planning on using a metal rear skirt, take heed of the above advice re: making the rear bow fit the rear skin perfectly. The top of the plexi must be in line with the top of the aft skin. If it doesn't fit perfectly, it's going to be really hard to get the rear skirts to fit nicely. I've seen very few metal rear skirts that look nice. I suspect that those who do end up with nice metal skirts had that rear bow perfect. I ended up going fiberglass and have no regrets. Had to learn another new skill though!
Good luck with yours.
Just a thought here. I think my metal skirts came out very well but the fit of my back bows was too low in places ,... meaning "not perfect". It is way better to be low than high in my opinion as the fix was pretty easy. After a rough fit on the metal skirts, I used felt drawer stops to shim up the canopy to the flush fit height required to make the metal skirts fit well. Then I "fitted" them a little more. (Here is where access to an English wheel really helps, see streaks in the aluminum finish)
Now I had pretty nice fitting skirts (second try) but lots of gaps between the skirt and the canopy that were taken up by the felt drawer stops. That would have made the canopy skirt loose or fit funny after riveting. Too fix that, I mised up a mess of West Epoxy and filler and laid it on the canopy just a skosh above the level of the felt stops, covered it with saran wrap, and then clecoed the skirt back down, then shut the canopy. After the epoxy cured, I took the skirt off, removed the saran wrap and had a perfect fit around the bows which makes fitting the skirt much easier.
I had the George Orndoff videos and he had to fit them twice as well. He also mentioned putting a 1/4 inch spacer between the front canopy bow and the roll bar when fitting the skirts. If they are pretty tight with the spacer, they will be really snug when you pull them out.
If I were ever to do it again, I would make the bows close to even or low all the way around, then build up the canopy to a perfect fit and only then start to fit the skirts. This would be perfectly backward from anything I've seen but having done the build up now, I think it would be a lot easier almost foolproof.
Also painted the inside 3 inches on the back of the canopy so that the glass work wouldn't show from the inside which acutally makes it look very finished.
I also wonder if all the "plexiglass pulling the frame out" isn't about the skirts being fitted in tension instead of fit to "fit". It took two large guys and some 2x4s to bend my frame to shape and I just can't see any way the flimsy plexi can "pull" it out of position. Did not happen in my case but I have heard a lot of folks who say it has.
Just a different look at it.
Bill S
7a