Here is the way I engineered my gap.
I believe the gap between the frame and the plexi is important for the Sikaflex to do its job. Here is how I did it.
1. First, I positioned the cut canopy on the frame and drilled #40 holes to fix the canopy to the frame with clecos. Every 3 to 4 inches worked out about right.
2. Next, I used electrical tape to mask out where the Sikaflex would go on the canopy and on the frame. I then sanded the part of the canopy and frame where it would be bonded.
3. I then went to the aviation section of my local hardware store and bought the thickest small o-rings I could find. The diameter of the 0-rings was about 3/16" and they were about 1/8" thick. The trick is to cleco the o-riings between the plexiglas canopy and the frame, leaving a small gap for the Sikaflex.
4. After mocking everything up and determining that the holes/clecos/o-rings were spaced close enough to ensure a fairly uniform gap between the canopy and the frame, take everything back apart.
5. When you are ready for the big fix, get a friend with a steady hand and a caulk gun. Load the Sikaflex into the caulk gun, clean both the canopy and the frame surfaces that are going to be glued together and then paint both surfaces with that expensive primer they sell. Use a cheap 1" bristle brush. The foam brushes are too limp for the job.
6. Once the primer is a little dry (it does not take long), Cleco the canopy onto the frame, with one o-ring between the canopy and the frame for each hole.
7. Then, use the caulk gun and a rubber gloved finger to shoot the Sikaflex into the gap between the plexi and the frame. Use your finger to smooth the fillet. Have plenty of gloves handy, because they gum up easily and it works better if you change gloves often. If your electrical tape barrier is placed correctly, the fillet should be just about right, overlapping the tape just a hair.
8. Once all of your fillets have been shot and smoothed, pull off the tape, because Sikaflex sets pretty fast. That is why it is good to have a friend helping. The two of you can finish the canopy before everything sets.
9. Once the Sikaflex has set, you are good to go. Don't worry about the little o-rings encased in the adhesive, they are now just part of the matrix. This procedure works better than the sliced hose spacers, because you do not have to go back and remove the spacers and fill the holes.
For me, this worked like a charm on my 8A. It helped to have my old buddy, Sam Beale flying wing on the big event. He was a wizard with the finger fillet maneuver.
