Before gluing on the filler foam blocks on the canopy frame arms, I noticed that I had a small problem on the right side of the canopy. One that could become a major drag during the upcoming fiberglass work. The problem was that the aluminum side skirt was not closely following the curve of the canopy glass where it was supposed to smoothly flow into the curvature of the forward fuselage. Instead, it was gaping away quite a bit.
During the layup, epoxy would flow into that gap as well as the fibergass cloth would sag into the opening. This would create an area that would have to get filled up to smoothen it - followed by a lot of sanding.
It looked much easier to fix the problem now by attaching the aluminum more closely to the canopy. I did just that by pulling the skirt away a bit, roughing up the glass with a Scotchbrite pad and injecting some fast curing, thick epoxy and clamping it down.
This resulted in a very nice curve and will hopefully save me a lot of work later.
Next were the foam blocks. Besides the tapering to adjust for the angle in the arms of the canopy, they also had to get trimmed to follow the outer shape of the arms. Tipping up the canopy allowed the Sharpie to mark the outlines.
The bandsaw made this a very short task. The hole for the bolt was a different story though. I just had a 3/4" step drill but I doubt there would have been enough room to actually use the 7/8" drill they asked for. The hole gets really close to the surrounding material and the foam is not very strong. After drilling the 3/4" hole I used a fine half-round file to enlarge the opening just enough to allow for the clearance of the bolt and the washer.
Due to another builder's blog I had trimmed the canopy front much more than the required 1/8" clearance to the panel. Actually it looks more like 1/4" now and the gap would allow resin to possibly stick to the front side of the forward bow. So I covered that bow with duct tape.
I also filled other holes and cavities were resin could get into the cockpit and cause ugly runs.
Then I glued the foam pieces in place, using the thick floxed epoxy that was asked for in this task.
I used the fast hardener with the West Systems 105 resin. While the epoxy was curing I worked on a previous task that I had to delay as I was waiting for the raw material to arrive from Van's - the guide blocks.
At first I was a bit at a loss as to how to shape this gummy material but then found the belt sander to work quite ok.
Installing them per plans caused some interference between the rearmost screw and nut on the canopy skirts.
A bit more of a problem on the passenger side than on the pilot's side. So, off they came again and yet another session at the belt sander relieved the guide blocks of their forward lower outer edge as to clear the screw and nut.
The epoxy had cured in the meanwhile and I manufactured a sanding tool for shaping them in the next step. I used an 18" long piece of a 2x4 and used the slow curing epoxy to attach some 60 grit sandpaper to it. Because of the slow curing epoxy (to fully soak into paper and wood, I had to let it sit over night. Oh, and some of my reloading equipment helped with this task too ( about 4000 rounds of 180gr. bullets are a nice weight to press the wood against the sandpaper).
Not too many words for the next pictures. It took quite a while to sand this to shape. Mainly because there is just so much material to be removed.
Done! On the pilot side I remembered that I had a cute little tool to shape balsa wood just as I had to shape the foam right now. It's a small planer that uses a common razor blade. After a short search I found it. It made this task much much quicker.
Just be careful not to remove too much with the planer, then sand down the rest.
You can't see it in the picture but I also used a layer of packaging tape (the slickest you can find) over the existing duct tape around the foam block. This prevented the duct tape from getting roughed up and the resin later sticking to it. I removed the packaging tape after the sanding.
The result of this weekend was that I have perfectly shaped foam blocks glued to the fore arms of the canopy frame. The gaps of the canopy are all filled to keep epoxy from running into the cockpit area excessively and the cloth should also not sag too much into low areas around the forward canopy support bow (a photo, I have not taken yet).
I hope to continue the prep work for the layup during the week, so to be ready for the actual fiberglassing on the weekend. I have yet to cut the fiberglass cloth, and the template and mask the canopy layup line with electric tape.
Some might call this stalling but I remember from my RC model days that the magic of fiberglassing is in the preparation. The job is much less tedious when properly prepared and planned for.
And, it's not that I would have much else to do either. I am still waiting for the SkyView, although some Van's people are at least talking to me about it now, so there's hope. Dave in Ohio made a good decision to delay his SV adventure until the summer. By then this might all have turned into a boring cookie-cutter package holiday, which - in the case of avionics - is a very desirable way of spending your (building) time.
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