Chapter 9 - Step 1

This step involves adding reinforcement layups to the landing gear bulkheads and the firewall.

Torque Tube Pilot Holes July 22, 2000. This isn't really chapter 9 work but this is when I did it. Since the plans keep talking about redrilling the torque tube holes after each reinforcement cures, I figured now was a good time to make those holes.

I started by marking where the holes are supposed to go. From there I used the 12" long 1/4" drill bit to make sure all three pilot holes were in a line. I'm hoping they are supposed to be.

Making a Torque Tube Hole July 22, 2000. Once the pilot holes were made I slid a 7/8" hole saw into the 1/4" drill bit. With the bit in the pilot holes I was assured the 7/8" hole would be in the right place. After making the first hole I readjusted the location of the hole saw and made the other torque tube hole.

The hole saw I used worked great. It is a Master Mechanic Bi-metal hole saw. It slides onto a 1/4" drill bit and is locked in place on the bit with a simple set screw. Clark Canedy suggested these on the builders list as a replacement for the spot facing tool. These hole saws work great and only cost about $11 instead of the $36 for the "special" spot facing tool.

Torque Tube Holes July 22, 2000. I now have two perfectly aligned torque tube holes in the aft and forward landing gear bulkheads and a pilot hole in the firewall that is in line with the others.

Reinforcement 1 Outline July 22, 2000. In preparation for the reinforcement layups I sanded and trimmed all the affected areas. I then marked an outline for the reinforcement. It's hard to see in this picture but I traced an outline based on the dimensions in the plans.

Reiforcement 1 Fiberglass July 22, 2000. Instead of making a paper pattern for the fiberglass I just cut a piece of BID that would be big enough. This worked out to be about 23"x10" for me. I also figured I could apply this reinforcement without having to cut a dart. I layed the rectangle in place and pushed and poked until it fit around all the curves and jogs. Sure enough the BID contorted itself enough to lay down without needing to cut a dart. I then marked the outline on the glass in place.

I then removed the glass and layed it on the workbench and put it back into the original rectangle shape. This was put on top of the other two plies. I then cut all three plies at once to the outline which is what you see in this picture. The forward, outboard corner of the reinforcement would go over the middle of the seatbelt mount so I cut around it so I wouldn't have a bump where the aluminum bracket would go.

The two smaller layers were made from simple 7" squares.

Reiforcement 1 Complete July 22, 2000. I added each of the five plies one at a time to the fuselage. There was no way I would have been able to wet out the three layers on the workbench and then transfer them into place. The layers need to zig and zag around bends and the doubler too much.

I will admit that out of the six total pieces, only one went on easily. I only got completely frustrated by one layer but got it worked out. The other four were not too bad though. The two smaller pieces went on very easy.

Reiforcement 2 Fiberglass July 23, 2000. For the second reinforcement I decided to try the paper pattern since the contours were simpler than the previous one. It didn't take too long to get it right but of course it required a dart to be cut.

I then cut all the glass to rough size, layed the three layers on top of each other and then used the paper pattern to cut them to exact size. I then wet out all three layers at once on a sheet of 4mil plastic, cut the dart, and applied the wet layers to the fuselage. Worked pretty well. I then wet out the other two layers, which were simple rectangles, and applied them in one shot as well.

Reiforcement 2 Complete July 23, 2000. One side is complete. Peel ply has been added where the smaller layers overlap the larger layers, like always.

Reiforcement 3 Fiberglass July 28, 2000. The last reinforcements comprised of three shapes. I made a paper pattern for the outboard most one. This time I cut the glass a bit big, wet up the three layers, then cut the layup to shape with scissors while the pattern was held in place under the plastic. I then transfered the layup into place on the fuselage and pressed it into place. The other two layups where simple rectangles.

Reiforcement 3 Complete July 29, 2000. Here are all the parts of the last reinforcement in place.

Reiforcement 3 Complete July 29, 2000. More detail of the reinforcement over the NACA duct foam.

All Reiforcements Complete July 29, 2000. A shot of all three reinforcements on the left side. All the peel ply is still in place.