The lower left wing has had the most challenges. When I disconnected the aileron push rod I found the aileron didn't swing up far enough to get the screws out of the hinges. The problem has to do with all these 9 degree angles. Ill fix this problem later. For now I had to remove the cotter pins at each end of the 5 hinges and drive out the hinge pins. Then I could remove the screws and hinges to allow the fabric to be removed.
The hinges were numbered inboard (1) to outboard (5) so they can be matched up with their other halves on the aileron.
When I tried removing the bolts for the brace wire/strut fittings I found them even harder to remove then the right wing. They are rusty but still structurally sound. All that expanded rust just jammed them in.
I'll re-drill the bolt holes 1/32" oversize.
I found a couple drag cables with a lot of excess cable after the Nicopress sleeve. I bent a scrap of 20 gauge mild steel to hang over the cable to protect it while I cut off the cable with the Dremel Tool cut off wheel. The ends of the cables were again taped with friction tape and shellacked.
Were your eye protection it throws plenty of steel dust.
The pitot and static lines were made with nylon tubing. It has worked fine but after 40 years it made no sense to trust it any longer. I replace them with aluminum tubing. To do this the leading edge had to be opened. I decided to un-nail the inboard section along the underside of the wing. This worked because it overlapped the outer section. on the outer section I removed just enough nails to get the tubes loose from the ribs.
I color coded the new tubes and will mark which is pitot and which is static when I reassemble everything to make sure I get them hooked up correctly. There was an access panel but I extended it a little to make it easier to tighten the fittings.
The nylon tubing was cable tied to the nose ribs. I used the friction tape for the aluminum tubing.
At the inboard end I moved the connectors outboard a few inches, attached them to a floating bulkhead to make it easier to hold them while connecting them to the tubing from the fuselage. I also added a small access panel.
The leading edge skins were nailed back on with nails 1/8" longer and any loose nails replaced.
The tie down ring on this wing also had a crack so I decided to make new ones, turned with the wind. I bought some rings at the hardware store and sand blasted off the plating. I ground just enough of a flat spot so the ring would stand on its own while welding. I tacked both sides then torch welded them to the new plates.
After drilling the holes in the plates to match each wing I stamped them to make it easy to install them, "R" for right and "F" for forward end, etc.
After grit blasting, painting and baking they look good.
I forgot to take some pictures here. The aft section of the outboard rib on the wing walk broke loose. For some reason the aft portion of the cap strip on this rib was only about 3/16" thick so the groove where the rib web is glued in wasn't strong enough on the one rib which gets highly loaded when you step on the walk. It's hard to step near the inboard rib. I glued and clamped it all back together. After the glue dried I cut a piece of 1/8" plywood to fit next to the rib web. The idea was to glue in a piece which would allow another piece of 1/8" plywood to be glued to this piece and to the cap strips. The forward end of these pieces were ground at an angle to fit the corner block. It was all glued and clamped together. After it dried the excess glue and plywood were trimmed to a nice fit.
When the wing is recovered I'll start the wing walk grit at the spar to help make sure this doesn't break again.
When the step sagged the trailing edge bent letting water puddle at the next rib and the end rotted off.
To fix it I cut a block of spruce the width of the cap strips to replace the end of the rib and made 1/16" plywood gussets for the sides, per CAM 18 (yeah I know it's been superseded).
All of it was fitted up glued and clamped together. I've used T-88 glue for all the repairs despite my preference for Resorcinol, because there are gaps which fill better with T-88.
After the glue set up it was all sanded to a nice new rib end.
Rib 5 (root rib is 1) got damaged, probably while moving the wings over the past 20 years. The lower cap strip and the 1/16" plywood web were damaged. I cut a new piece of spruce cap strip with a 12:1 taper for the splices. I used an Exacto saw to cut the 12:1 taper on the old cap strip and then carefully trimmed it from the plywood web. Plywood gussets were made to cover the splices and everything was glued and clamped together.
Pieces of 1/16" plywood were glued to the sides of the broken web. I used the Exacto saw to cut a split in each piece to get them over the wire without undoing it. The slits are on the undamaged area and run at about a 30 degree angle, one forward and one aft.
All the repairs were varnished and as done on the other panels any wood that fabric touches was epoxy varnished.
With the woodwork done I needed to replace the bent section of aluminum trailing edge. The piece I ordered from Aircraft Spruce exactly matched the piece from 1975. To flatten the areas where it fit over the ribs I clamped a dolly tightly in the vise and hammered the areas flat on the top and bottom.
The ends had to fit over the plywood which was thicker than the ribs. To open the radius at the trailing edge I used a piece of 1 1/2" x 1/8" steel angle with a piece of 0.032" aluminum wrapped around the edge. You could probably use a small piece of the trailing edge material to cover the angle.
I slipped the trailing edge over it and squeezed it in the vice. With it tight in the vise I used my fingers to fold the legs it back to a tight fit.
You can see how much wider the radius is now.
It fit nicely onto the plywood.
For reasons I can not guess the trailing edge of the ribs do not line up with the plywood at the step and the aileron cut out. The nails hold the trailing edge on but can not take any load from the fabric pulling tight. I put a blob of epoxy putty in the trailing edge at each rib and pushed the trailing edge onto the ribs so the putty was smashed around the end of each rib. I can't imaging they will come loose or that the fabric will pull the trailing edge in.
It's hard to get nails through the trailing edge material. I used the automatic prick punch to put a weak spot for each nail to go through.
The weak spots worked great. All the nails went right through without bending. I needed something solid to support the tip of each rib while pounding the nails. I was going to cut a piece of 2x4 but I had this shovel handle I've been cutting up to make form tools, cheap source of round hardwood. It was the perfect length and made nailing a cinch.
New trailing edge, straight and solid. All the nails are covered with small pieces of aluminum tape. In the Air Force we called it High Speed tape. You could use it on the outside of a jet without coming loose.
I made the drain holes in the trailing edge larger than the holes in the wood to assure good drainage.
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