Finished Right Wingtip Mount

Today I drilled the top mounting holes for the right wingtip and clecoed everything in place. I’m still going to have to do some work on the gap between the fiberglass and aluminum to try and get something that is rain tight. I walked over to Danny’s hangar to see how Vans solves the problem, and I really like their solution. His RV-7 has the outboard wing rib mounted about 1.5 inches inboard of the end of the skin, which allows that the fiberglass part fits under the wing skin. In this case, there are no waves at the fasteners because the wing skin spreads the load like a giant washer. Since the skin is only .025″ thick, from arms length it looks flush. If the inboard edge of the fiberglass isn’t perfectly straight, it doesn’t show, since it is under the aluminum. This would be a cool feature to incorporate for a scratch builder, but I can’t see how it would be practical to do this late in the game. Here are some pictures of the vans setup:

Vans Wingtip

Note that the fiberglass is under the wing skin

Wider Angle - From here there are no waves, and it looks flush because the wing skin is so thin.

At the Aileron it switches to fiberglass on top.

While I had the wingtip mounted, I wanted to see how hard it was going to be to remove the ridge that the wingtip had as a result of the mold. The fiberglass is pretty thick in that section, and I was able to file the ridge flush without getting through the white coat in all but just a few spots. With some filler and wet sanding, this tip will look great.

This is the ridge left during the manufacturing of the wingtip. The file takes it right off.

Here I am filing off the ridge, not straying too far from the propane heater.

Now I get to do it all again. I’m glad this isn’t a biplane!