Today I fit the side skins on the canopy. I needed to make some adjustments to break the edge evenly, as the dumpling process had flattened out the edge near the dimples.
One thing I read was that it’s best to run the wiring for the canopy latch micro switch before riveting the side skins on. So I dug up the canopy wiring fit and ran the two wires that are needed to operate the switch. then I clecoed on the side skins.
Tonight I finished countersinking all the holes in the canopy, and dimpled the canopy side skins.
I had actually jumped ahead in the plans because I wanted to avoid taking the canopy on and off repeatedly to avoid scratches. Next I’ll be reinstalling the canopy on the frame, then marking out the location of the canopy fairing.
Last night I finally finished painting the cockpit area and the canopy frame. It took a lot of touch-up coats to ensure all the surfaces were covered, and it was more time consuming than I anticipated.
The last thing I did was strip off the primer I had painted on the outside of the forward canopy skin. I had painted this in a somewhat absent-minded moment earlier in the canopy frame construction. The aft part of the skin is painted mat black to minimize reflections on the canopy.
With the painting done, I peeled off the paper and tape, and was happy with the way everything turned out. It’s far from perfect, but it’s adequate for me given my limited experience and sub-optimal painting environment.
To keep it out of the way, I moved the frame back onto the airplane, then set the canopy onto the workbench. I then countersunk all of the holes along the trailing edge for #6 screws. I used some vinyl tape on the countersunk cage which helped stop any rotation and scratching.
Over the last couple of days I’ve been painting the cockpit, and the canopy frame. I’m using stewart systems’ finish coat, battleship grey, and adding some flattener to get a flat finish.
I’m still learning as I go, and feel like I’m gradually getting a more consistent application. It’s still far from perfect, but it’s good enough for what I need. I’ve needed to tweak the amount of water I’m using to thin the paint because of the flattener. Less water seems to be the way to go to avoid runs and splotches. Waiting for 15 minutes between thin fog coats helps to build up the color and result in a consistent looking finish. Good lighting helps a lot.
At this point I have one more coat to apply to the roll bar, but otherwise it’s done for now. Hoping to finish this paint job tonight.
Tonight I finished drilling holes in the canopy, and then final-sized all of the holes to #27,
I only had one scary moment, when for some reason one of the pilot holes I drilled in the aft edge didn’t line up with the pre-punched hole I was shooting for. However, I was able to enlarge the pilot hole slightly to get it to line up, and then the final-sizing took care of the problem, leaving a nice round hole in the right place.
More drilling tonight. I’m going slowly, but so far everything is working out nicely.
Match drilling the side rails takes some care. Because the aluminum rail is pressed up against the Perspex, and there are no pilot holes, the Perspex drill bit doesn’t completely exit the Perspex before contacting the aluminum rail. Switching to a regular drill bit and drilling through the aluminum rail requires drilling through the last few millimeters of Perspex with a regular drill bit, which risks a crack on the backside of the Perspex. I don’t expect to find any issues, but I’ll carefully inspect it when I disassemble in a subsequent step.
The wooden structure inside the cockpit is providing great support for drilling the canopy rails.
Tonight I drilled the first set of holes in the canopy. Everything went well and the holes were as accurate as I could have hoped for.
I made a small sighting tool by bending a piece of aluminum to 90 degrees. I used this to sight a spot on the canopy that was directly over the hole in the underlying frame, then marked the spot with a sharpie. Then I taped it to the side of the hole to help me keep the drill square. Then I lined up the drill on the spot, checked the placement, and drilled the hole.
Life has gotten busy recently! Tonight I finally finished trimming the canopy, and got everything ready to start drilling the holes.
I used a ratchet strap to hold weight on the front of the canopy, and rigged up some blocks of wood on the inside to backstop the holes being drilled through the side rails.
I plan to start drilling tomorrow, as it’s late and I need to get some sleep tonight.
Tonight I messed around with the side skins on the canopy trying to see if I could minimize the gap between the canopy side skin and the fuselage side skin. Eventually I decided to just go with the existing skins and worry about the gap later, if it’s an issue.
I moved on and measured the thickness of the canopy on the sides to determine whether I needed the use the supplied shims. If the thickness is less than .17 of an inch the shims are required. On the right side I measured between .158 and .17, and on the left I measured between .147 and .158. The thickness varies along the edge, hence the ranges. So it looks like I’ll be using the shims.
Work has been keeping me busy in the evenings the last few weeks, but last night I was able to spend some time in the garage. I trimmed the canopy sides to get it to sit flush with the canopy rails, and to sit down correctly on the forward canopy frame skin. I used a combination of a diamond blade on the jug saw, a sanding block, and a burred edge on a small steel ruler to cut, sand and scrape the edges. It wasn’t my favorite thing to do, as the canopy is bulky, flimsy and awkward, but it came out ok. Most of these edges will be hidden by skins and fairing, so the straightness of these edges wasn’t critical.
