A few months back, I accidentally punched a hole in the aileron nose skin. I had glued a patch over the hole, but it needed a skim coat of epoxy and micro filler to smooth it out. I did that, and used the left over mix to fill in the gaps between the two plywood wing walk skins, and a little gap along the edge where the wing walk skin meets the root rib. Next step is to make the final torque tube bearings, I think, and wait for a hardware order from Aircraft Spruce to finish attaching the last of the brackets – then this wing is ready for storage and eventual covering.
Fixing transit damage
As we were moving the wing, I managed to snag the root rib on the corner of the workbench at Stu’s shop while we were getting it positioned to load into my pickup. This popped a couple of glue joints loose, both of which pulled the wood apart rather than just the epoxy breaking, so that’s as it should be.
I also found an inch long crack in the leading edge plywood in the second rib bay, forward of the wing walk. I don’t know for certain if that happened during the move or at some time prior, when we were moving it off the bench. Doesn’t matter. Unfortunately it’s right on a curved part, and I was afraid I’d do more damage if I got too aggressive trying to pop the edges back together. I laid a layer of heavy fiberglass cloth on the inside of the leading edge. Once that was in place I buttered the outside with epoxy and micro balloons to make a filler, and taped plastic over it to keep it from sagging or dripping. I can sand it to the correct contour. I may add a second layer of glass underneath, I haven’t decided yet. What I did NOT do was remember that I had another place that needed a layer of micro (doh!) where I could have used the left-over I had. I didn’t realize this until the epoxy was well past the workable stage. Geez, I probably wasted two cents’ worth of material because of that!
It’s good to have the wing here; this all took less than half an hour but will take at least 8-12 hours to mostly cure. I can go back out this afternoon or evening and get more done.
Also, yesterday I picked up a Dust Deputy cyclonic dust separator for the shop. It was brand new in the box, and I got it for about 1/3 price. A welcome addition to the workshop for sure.
Compass overhaul
I think I’ve finished the compass overhaul. The rebuild kit arrived from ACS yesterday. After carefully cleaning the glass with denatured alcohol, I installed the new gasket and the glass. With everything reassembled, I filled it with compass fluid. I had about half a pint from a rebuild kit I had bought several years ago, when I came across an old Airpath compass that ultimately turned out to be an oddball military model for which there are no replacement parts or gaskets. It was leaky around the glass, and I eventually figured out that the cork gasket was slightly oversized. From what I can tell, it’s supposed to apply pressure around the edges of the glass to seal it against the inner black rubber gasket. It was getting squeezed between the case and face plate. After trimming about a millimeter or so from the outside, I finally got it to seal up.
Normally you would submerge the compass in a container of fluid to work out all the bubbles. In fact, the Airpath manual specifies submerging it and pulling a vacuum for a few hours to ensure there is no trapped or dissolved air. I didn’t go to those lengths. I was able to work all the bubbles out and get the fill (or drain) plug in, and so far there’s no sign of leakage.
The new LED lamp works great. In a dark room there’s a nice red light that makes the compass quite readable. I’m happy with it.
I’ll let it sit on the bench for a few more days to ensure there’s no leak and no bubbles develop. If I do see any air, I’ll submerge it in a container and do it their way. I figure it won’t be getting mounted in a panel for at least a year or two, maybe longer, so I’ll have plenty of time to validate the quality of the rebuild. For a total investment of less than $71 I’ve got a completely rebuilt, well lighted Airpath compass. That total includes an extra nine little LED lamps that I’ll use elsewhere; if you don’t count those it’s under $65 total. Not bad considering I see dried-out junkers going for more than that on Fleabay.