Right Bottom Inboard Skin Done

Time: 8 Hours

What a beautiful day here in Chicago, sunny and low 80°’s with a little breeze. I got out into the Hangar early this morning to get to work. I started out making the scarf joint where the two bottom skins overlap at the forward edge. This is so they meet the fuel tank skin close to flush. I just repeated the process as I did on the left wing by removing some material and testing the fit. It took several attempts but I think I have a nice joint now. Most of the day was back breaking and tweaking riveting just like the other wing. I will say that it went a little faster but not much. It is just a real pain bucking these rivets. I used several different bucking bars to get all the rivets. I bucked all the rivets except the inboard edge and the hinge line as I could get those with the pneumatic squeezer.

After squeezing the inboard edge I quickly took care if the hinge line by removing the wing side of the hinge from the flap. Once all the riveting was done I grabbed the flap and reattached the hinge pins to both sides of the hinge and secured the flap and aileron with the blocking I made yesterday.

I then removed all the blue film to clean up the skin. I made 2 small dings in the left bottom skin so I did better on the right as I only made 1 small ding. It looks worse in the photo than it really is. Nothing a good painter can’t fix and make completely disappear.

After I finished up that task I turned to the conduit for the right wing just like I did for the left wing. I copied the hole between the ribs where the autopilot servo will sit for the control of the aileron.

I started the prep, just removing the blue film, on the right outboard skin for tomorrow’s work and put the skin on the wing for safe keeping.

The last item I did today was to finish up the access hole plates, I did 1 yesterday, so I needed to finish up the 5 remaining ones.

Another good day in the Hangar! Now off for a little mountain bike ride this evening!

Misc. Wing Work

Time: 6 Hours

It’s been about a week since I was in the Hangar to do some work since the Memorial Day weekend and my flying. When I got to work I decided to finish up some items on the left wing before working on the right wing inboard skin. I started out working on the CPVC conduit I’m using for running my electrical wires in through the wings. So I grabbed the pipe and slid it into position. I was real happy with the fit and it had just the right amount of tension between ribs. The holes are off just a hair which is good as it helps grab the pipe with friction and help hold it in place. I cut each end square and even with the skin overhang on the last inboard/outboard ribs. I will eventually add some ProSeal to hold these pipes permanently.

Once it was in position I marked a hole in between the ribs where the pitot heat controller will be housed. I then took the pipe out and drilled a hole with the drill press and pipe drilling jig. I then cleaned up all the edges on the hole and both ends. With the pipe back in position in the wing I inserted a rubber grommet that I got from Ace Hardware to protect the wires from chaffing. Before I permanently install this pipe I will run several strands of string from inboard to outboard as well as inboard to the middle hole I drilled. These will be used later to pull the wires through the pipe.

I was holding the left flap/aileron together with a clamp and wanted to make up something that I could leave on there for a longer period as I would need that clamp later. I will eventually buy a gust lock that will go there to hold it all together in storage but for now I will make mine. I just used 2 pieces of 1/2″ plywood cut at 2.5″ x 5″. I used the drill press to drill a single 3/16″ hole at the proper angle to correspond with the angle of the flap/aileron skins. I then used some self adhesive felt sheets to line the inside of each piece of wood. A 3″ 3/16″ carriage bolt, washer and wing nut finished it off. I repeated the process and made a second one for the right wing when needed.

I then turned my attention to the right inboard bottom skin for a little while. I need to rivet it to the wing like I did to the left wing but before I do that I wanted to tackle the vent first. There is a NACA vent hole in this skin that Van’s has you rivet a plastic NACA scoop to later in the build. This scoop will funnel air to a vent for the back seat passenger. My friend Glen said it is much easier to tackle this now rather than latter when the skin is all riveted to the wing. Off the wing it was a very easy task to complete. I just took some measurements for 6 rivets and where I wanted them to go around the edge. I then used some tape to position and hold the scoop in place on the inside of the skin after positioning it just as I wanted. I then flipped the skin over and traced the outline for later. I removed the scoop and flipped the skin and drilled the 6 holes. I then re-tapped the scoop into position using the outline and tapped it down real good. I could now use the 6 holes I just drilled as a guide to drill the scoop.

I deburred all the holes in the skin and dimpled them. I used my countersink bit with my fingers to countersink the holes in the plastic to accept the dimples on the skin. I scuffed the skin up just inside of the outline I made and on the flange if the scoop then cleaned everything up with alcohol. I grabbed a little bit of ProSeal and mixed it up and buttered the flange of the scoop, this is just to help hold it in place and seal it to the skin so all the air makes it into the cabin.

I then placed some soft 426 rivets in the holes and taped them with my back riveting tape. With the skin flipped and now resting on my back riveting steal plate I riveted the 6 holes at a low pressure since they were the soft rivets. This came out beautiful and looked very nice.

I’m going to let the ProSeal cure overnight before I start riveting that bottom skin so I don’t get it all over my arms. So I moved on to the outboard bottom skin prep. I’m not going to rivet these for a while or at least until I’m sure I’m not going to change and internal wing stuff that would need access inside the wings. So I will just deburr and dimple these skins so they will be all ready to rivet once I decide to. I also primed the inside flange of the access hole and riveted the nutplates on just like the inboard skins.

Before dimpling the inboard edge holes I formed the edge with the edge roller, leaving a small section at the aft edge undone as it doesn’t overlap the inboard skin for a couple inches. I then clecko’d the skin in place.

One last item that I wanted to do was complete one if the access hole plates. These have #8 screws around the perimeter except where it overlaps the spar and those are #6 screws. I debured the edges and drilled the holes to the correct sizes and dimpled them with the pneumatic squeezer. Pretty easy but I wanted to see how it looks in place. I will finish up the 5 remaining ones as I have time.

A pretty good day in the Hangar and it felt good to get back at it!

Left Bottom Inboard Skin Done

Time: 4 Hours

I got to spend a little time in the Hangar yesterday when I got home. The task at hand was to finish up the right bottom inboard skin and flap hinge. Again I have to say that riveting these skins is a pain by yourself although I’m not sure it would be much easier with a helper. I really strain to reach the rivets at the rear spar, or top as it sits in the cradle, since the opening is so small. I was able to get all the rivets done except the 2 rows where the outboard skin overlaps the inboard since those will be the very last rivets done. I took my time and several breaks to keep my arm and back pain in check. I did have 2 small (character as my friend Glen calls them) dings, 1 from the bucking bar in the inside and 1 from the rivet gun. They are super small and the painter will have those taken care of. Good thing is that it’s in the bottom of the wing and no one would ever see them if they were bad. I then grabbed the pneumatic squeezer and hit all the inboard edge rivets along with the wing half of the flap hinge. With every rivet done that I could do now I slid the hinge pins in the flap to see how everything looked. I’m happy to say that it looks awesome!

Bottom Inboard Skins Started

Time: 3 Hours

I decided to get some work done in the Hangar today, my home schedule has been pretty busy with flying and spending time with my girl since she is in town for an expo downtown Chicago. My next big task is to get the inboard bottom wing skins riveted on. I have been dreading this task as it is very hard to get inside the wing to buck the rivets. Before I could start I needed to scarf the joint where the inboard and outboard skins overlap just as I did for the top skins. I’m working on the left wing today as I knew that trying to get both wings done would be nearly impossible lay the same time.

Once I was happy with the overlap I checko’ed the skin to the rear spar and no where else. I need to be able to lift up the skin at the forward end to slip my hand and bucking bar all the way into the wing to get to the rear spar rivets. This is a lot of work and very difficult especially between the wing walk ribs. I worked from inboard to outboard on the rear spar rivets until I was outboard of the last wing walk rib. I then went back and went aft along the second inboard rib (the first I will get with the squeezer later) for 4 rivets. I moved to the next rib outboard and went down 2 rivets. Moving back to the first rib I added 2 more rivets followed by 2 more on the 3rd rib. I then went to the 4th rib and did 2 rivets. Can you see the pattern? I was stepping the rivets as I worked outboard. It took me 1 hour to get 43 rivets done as this is very difficult. I have to use a mirror and flashlight just to inspect the quality. I have had to drill out 2 so far as I let the bucking bar slip I guess.

I finished up all the wing walk ribs and decided that I would stop there. I had a meeting to attend then off to dinner downtown with my girl. I have read that these rivets take a while since they are so hard and I don’t want to push it. The rest if the week and weekend will be shot for hangar work as it is the Memorial Day weekend. After that I will get back hard at it.

Flaps Drilled

Time: 5 Hours

Today’s task was to get both flaps drilled to the wings. If you remember that I left the wing side of the flap hinge undrilled so that I could make any adjustments so the trailing edges of the ailerons/flaps aligned. This was the time for me to get everything aligned so I could drill the hinges. There are several areas that I had to work with. One was to keep a 1/4″ gap between the flap and aileron. Another was to keep the trailing edges of the flap and aileron straight with each other as they run from inboard to outboard. The other was to make sure I didn’t run out of edge distance on the hinge flange as I made these adjustments. I have read many builders websites where they come close to the edge distance problem. Van’s calls for a 3/16″ edge distance minimum. Edge distance is measure from the center of the rivet hole to the edge of the hole. So I drew a line on the hinge to represent my line I can’t cross for reference.

I then used my 2 spring clamps to attach the flap to the wing.

I then spent an hour fine tuning all the angles and edges until I was perfectly happy with all the alignments and drilled one hole at the outboard end and clecko’d it in place. I then rechecked all the alignments and when I was happy I drilled the inboard hole and clecko’d it as well. I rechecked all the alignments once again and when I was happy I worked my way down the line drilling a hole and cleckoing it until I had all the holes complete.

I removed the flap and the hinge and was happy to see that I was good on all my edge distances! As with all the steps on this plane the second time goes a little faster. I had lefts side done in about half the time as the right. On the right flap the inboard edge, closest to the aileron was the side that needed to be lifted or moved aft in order to get the alignment just right. To opposite was true of the left wing. I’m guessing this is normal and this is why they use this process to remove any inconsistencies in the trailing edges. This hinge is on the bottom of the wing and no one will see it so symmetry between the wings is not necessary. All in all it was a fun day in the Hangar and had a little head scratching at times.