More wingtip work

October 18, 2012 – I finished glassing the wingtip ribs. For my first fiberglass work, I think they came out pretty well.

Since one of the purposes of these ribs is to support wiring for the lighting, I was weighing several options for how to install clamps in these ribs. I thought about threaded inserts of some sort, but I decided if they needed maintenance down the road, they would be difficult to work on or replace. I figured it would be easy to just run a bolt or screw through the rib and use area washers. What I decided to do was to use the longer screws and washers, but I gave the screw holes a little bit of support. I drilled the holes in the ribs where the screws would go, and I inserted aluminum bushings held in with sealant. If something ever happened with these, they would be easy to remove and replace. The bushings I used are just a little shorter than the width of the finished ribs, but I don’t really see a problem with that. Below are pictures of both sides of a rib with the bushings installed.

I also drilled the aft metal ribs that I made here. I piloted the wingtips with #40 holes, then drilled the ribs, then I took the holes up to #30. I’m going to attach the ribs with sealant and CS4-4 rivets.

Another item that I wanted to do on the wingtips is to reinforce the trailing edges, because they will likely need to be trimmed to match the trailing edge of the ailerons. I would rather add material on the inside of the tip instead of on the outside. I stood the wingtip between two padded sawhorses, mixed some flox with resin, and got it down in the inside of a wingtip. It looks like it laid down nicely. I may not have to cut that far when I trim, but I feel better knowing that the extra material is there.

I’ll do the other wingtip after this one sets up.

Time: 6:00