Upper wing and other details
I spent the afternoon working on extending the right rear spar on the upper wing. I was able to finish cutting the scarf on the spar and laid out the extensions on the new spar stock. I'll rough those out on the bandsaw before working on the final fit later this week. Hopefully, it will be glued up during the next hangar session. Dad was working on rivet holes and countersinking for the sheet metal on the fuselage. All of the sheet metal screws are getting replaced by machine screws and nutplates. No more stripped or loose sheet metal screws!
Earlier this week I got the outline of the upper rib template made. I need to route out the lightening holes and spar slots next. Then I can knock out the six new ribs needed for the upper wing tip extensions. I didn't remember to take any pictures, but I'll get them on the next trip to the hangar.
Prep work
We spent the afternoon doing clean-up and prep work on the upper wing. I'm trying to get everything ready for next weekend when we plan on doing all four spar extensions for the upper wing. I put in an order with Aircraft Spruce for supplies that should get us through lengthening the spars and making the new wing ribs. That should set us up well for starting the upper ailerons and figuring out the next details to tackle.
On the home front this week, I've got the spar extension for the second lower wing at the top of the list. I should be about ready to go and the wing is prepped. I can use any extra time to finish up the details on the first aileron and start planning the cove installation.
Wing tank removal
Dad came over to help out again tonight. Our main goal was to get the wing tank removed. He suggested using a router to mill out the edge of the plywood. This was a great idea. I setup a laminate trimmer to the right depth and clamped a fence to the spars so that I wouldn't damage the ribs on the sides. The sides were easy, but the front and back edges were a little more work and had to be done freehand. It all worked out well and caused zero damage to the spar splices and ribs. If only everything were this easy.
We knocked out a few more clean-up items on the wings before we wrapped up for the night. The next round should happen Sunday afternoon.
Bottom wing work
I finished most of the leading edge shaping for the first aileron. I'll probably tune it up a little, but it looks good. The spars on the second lower wing got sanded some more to prep for scarfing the spar extensions. I need to layout the spar center line to help locate the aileron hinge blocks and then I can add the extensions.
The fiberglass flanges for the exhaust tunnel got an extra ply of fiberglass laid where the nutplates will go. It looked a little thin for the countersunk rivets. I also built up the flange for the firewall with some flox. It will fill the little bit of gap caused by the aluminum angle on the bottom of the firewall. Most of the flox will get sanded off to get down to the thickness needed.
It's about time to put together an order for parts. I need some wood for the top wing spar extensions and new ribs, but there are a handful of other things that will be needed soon as well.
Top wing tear down
We got back out to the hangar tonight and started the tear down of the wing tips and outboard ribs. We managed to get the full size ribs off intact and I'll use them to create a router template for the new ribs that will be needed.
Top wing started
Dad came out to the hangar tonight to lend a hand. We were able to get the fabric and aluminum leading edges removed. The wings looked great except for the diagonal tip braces. They both had failed glue joints at the rear spar. The wood was basically undamaged. It looked like the joints had gaps too big for the Weldwood glue to handle. This is the only thing I've found on the wings of this nature. The rest of the joinery is solid and the Weldwood is really tough. For some reason, these joints just weren't fit as well.
The washers on all the drag and anti-drag wires are still flat. I didn't see any signs of damage to the blocks they are tensioned against. The nose ribs were also all completely intact. I was expecting to find some with damage, but it wasn't the case. All the full size ribs looked good as well.
We will start tearing down the wing tips for the conversion this Sunday. Feels like progress!
Small jobs
I've knocked out a bunch of smaller jobs over the last few days. The leading edge on the first aileron has been roughed into shape. I finished up a couple small welding tasks. The elevators and rudder got some corner gussets. The trailing edge tube on the rudder got oiled and sealed. I also spotted a weld on the fuselage that wasn't quite finished. It was at a weird angle and I didn't quite close the weld. That's fixed now. I started removing the baffles on the engine to get it ready for some maintenance and clean-up. I also started prepping the spars on the second lower wing for the spar extensions.
Work at home will continue on the bottom wings and new ailerons. Work at the hangar is shifting to setting up the work table for the top wing and going over the engine. We'll probably pull the fabric and leading edges off the top wing Friday after work. It will be interesting to see if it has held up as well as the lower wings have for 30+ years. I think the fabrication work is done on the fuselage, so it's time to double up on the wing work. When the lower wings are finished and go back to the hangar, I'll start working on other details like the new panel at home. Lots of little pieces and parts to complete.
Tunnel sheet metal finished
I got the stainless steel part finished tonight, which wraps up the bulk of the work on the tunnel sheet metal. I still have some minor trimming to do and a bunch of nutplates to install, but the hard parts are done.
I was having trouble bending the large radius in the stainless steel. I finally got it working by forming it between a steel pipe and a large piece of steel tubing that was split down the middle. The mess was pressed together using a vice. The radius came out just right, though the angle was a few degrees less than perfect. It all fits fine once the screws are installed.
I'm pleased with the results. This is pretty much the picture I had in my head when I first decided to build the fiberglass flanges. It's nice to see it finally work out.
Aileron Re-skin
Pulled the clamps off the aileron tonight for the second plywood skin. Everything looks good. I'm not seeing the scalloping that happened on the first pass. If I put a straight-edge on the aileron, I can tell where the ribs are, but between the ribs, the ply stays within 1/8" at the widest spacing. I don't think I can do any better and considering what fabric does between ribs, this will work just fine.
Back to the ailerons
Tonight I glued up the first skin on the aileron...again. It worked much better this time since the plywood was formed to a curve. I clamped up the ply between two halves of 4" PVC pipe. It was wet down a bit, clamped and then left overnight. It worked great.
