Canopy question. 34-05

Psyching myself up to tackle the canopy, and I have a question regarding section 34-05, detail A-A, and B-B. They call out a nominal spacing between the side of the C-1201 canopy, and the side rails of the WD-1219 canopy frame of 1/8". On first fitting, the canopy is almost a perfect fit everywhere, but it sits right on the side rails. Looks great so far. Should I space it to provide the 1/8" called out, or will it be ok to fit it contacting the side rails? I'm worried that the excellent fit everywhere else may be affected by shimming the bottom of the canopy. I know the canopy fitting process causes an undue amount of heartache among builders, but after all it is a one shot only deal, so I want as much info as possible before reaching 'the point of no return'.
Regards DaveH
120485

Canopy fitting

I just finished mine, and I would say leave as is...the big deal is fiberglassing the whole thing...major deal if you are not into fiberglassing...I ended up o.k. except the glass did not cover ahead of bolt that pivots canopy..my mistake...but if it was to cover ahead of this it would scrape on cowl..so have to do some adjusting and additional glassing..just a heads up going into glassing...I covered cowl with six mil visqueen...thinking it would be very small gap between cowl and canopy..did not think fiberglass/epoxy would stick to visqueen..wrong...but did get it apart and I have very small gap between canopy and cowl...good luck

Glassed mine up over the weekend. The gal that drives the fuel truck (says she's built a few Vans) said it would be fun. I was a bit nervous and watched the video on Vans twice. The first layer on the sides went well. Some how I mixed up layer 2 and 3 which was a stress moment trying to figure out how it could be so out of place. Once past that it wasn't a big deal. The fun came when I pulled the peel ply off the next day and it looked great. Did the bow that morning and it was actually fun.

Thanks for the replies, but it's not the fibreglass work I am concerned about. I was asking about the fit of the canopy bubble onto the frame.
Cheers, DaveH
120485

I made two complete canopies. The first one I wasn?t as careful, but followed Vans directions. When I finished it, I wished I took more time and did things a little different. Due to a mishap, I had the chance to do it all again and with better results. On my second build, I made sure the fame fit perfectly with all the correct clearances in every axis and in relationship to the roll bar. I filed down the welds on the canopy contact point of the round tube and on the outside of the square tube. I made a fixture to bend the frame so that I could closely control the bends while it was attached to the aircraft. I started at the pivot point and worked back to the roll bar using many iterations during the fit. When I bent and straightened the frame I made sure it would lift without any binding and that it would naturally lay flat and centered on the shims and spacers maintaining all the required clearances. I used washers as needed to space the frame on the pivot point to avoid scraping. It is important to use the wood spacers at the top near the latch. The blocks should space the frame without adding stress.
When I managed to get everything fitting to my standard, and it took some time to do, I clamped the frame to the roll bar and completed all the drilling, deburring riveting and fiber glassing of the canopy and frame without ever removing my clamps. I did not have the back window installed. That is how my helper entered and exited the aircraft. I did use duct tape and sand bags to hold the canopy in place during the drilling, bolting and fiber glassing operations. I completed my fiberglass work without unclamping the frame. I also added length to the templates so that the gap in the front of the canopy sides was covered. (My preference). I went through all this so that my seal kit would fit the gaps equally and without shimming and maybe keep out the drafts. This is how I did mine and it may not work for yours. Free advice is worth everything you paid for it. Good luck!

Looking at your question again, I missed the mark. The 1/8th inch gap between the plexi and frame is needed. The plexi will grow as you fasten it to the frame. You don't want to restrict the movement. That is why you start at the middle and work back And forth down each side a little at a time. It keeps the plexi centered on the frame.

Thanks for some very useful information
Cheers, DaveH
120485