More deburring and countersinking the wing - 3.5 hours

I decided to use 3/32" tank dies on the ribs and wing walk doubler (with regular dies for the skin). As such I double checked the countersink needed and came to the conclusion that it is the same depth of countersink that is needed for the thicker 0.035" skin. (As the wing walk doubler is 0.025" thick).

I ended up completing all the wing spar countersinks. Wow...what a lot of work. It's fun a first, but becomes very repetitive. I decided to re-tackle deburring for a bit before calling it a night.

Deburring/dimpling/countersink the wing - 5 hours

Well finally to the point where I can get working back on the wings. Earlier in the day I put in an order to aircraft spruce for some cherry rivets to attach the leading edge (also sent an email to vans support to ask about my options) but before I can get that I have a ton of work that can be done.

I need to remove the top skins and go to work deburring all holes, dimpling all ribs and the skins and countersinking the spar for all the dimples.

After I removed the top skins, I started in on deburring. Once I was done with the left wing/top. I dimpled the ribs. I then climbed in between the wings and kept deburring, and deburring and deburring.

Once I had my fill, I decided to do a little dimpling just to see how it was going to work out with dimpling the rear spar and the rib together. Not bad.



Then I moved onto some countersinking on the spar for all the #40 holes. I made absolute sure of what holes need a rivet to sit flush (the top row that connect the ribs but sit under the tank skin) all the holes that need to accept a 3/32 dimple for 0.025" skin (outboard skin) and those that need to accept a 3/32 dimple for 0.035" (inboard skin). After check, check and re-check I settled on a countersink diameter around 0.193" for the inboard skin dimples and then added a couple of clicks for the thicker inboard skins which ended up around 0.202" (give or take).

Countersinking works best and consistent if you go slow... Grrr.

Finished riveting the leading edge skin - 2 hours

My buddy Mike dropped by in the evening to lend a hand riveting the last few rivets that remain on the leading edge skin. These are a bit tricky to do by yourself (even though I managed to do it on the fuel tanks) it can be done by yourself, I just chose to get some help and make it easier.

Well.....what a pain the butt. Straight outta the gate we were batting 50% on the first few rivets. Had to drill some out and re shoot. One in particular was MURDER. Must have drilled it out 6 times. Well very frustrating. The rivet just did not want to sit flush. After much frustration we re grouped. I drilled it out to #30 and installed and oops rivet. After that order Mike had the gun a bit different and I held the bar a bit different, and we nailed every rivet after. Sheesh...it is true. Riveting is very much a feel and it takes a few to get it back again.

Started assembling the flaps - 4 hours

I had a little bit of edge finishing to do on the flap ribs so I started the day by taking care of those outstanding items. Once I was satisfied with all the ribs and the spars. I clecoed the assembly together and clecoed the bottom skin on.

Right away I noticed that I was not getting a good fit with respect to the rear spar. The plans want you to first drill the rear spar into the ribs, but I felt uncomfortable with this as there is a bit of play in the skin as the rearmost hole is not drilled. After much thought, I decided to remove the plastic from the skin to ensure a proper fit before drilling anything. I disassembled, used the soldering iron and removed the plastic. Then I re-assembled everything.

I gave it all a good look over. I was still uncomfortable with the fit at the rear. Just a bit of play on the skin/rib. My fear was that if I followed the plans and drilled the rear spar first, I risked poor fitment with the skin and the edge distance for the #30 rear hole is a bit sketchy. So I decided to drill and cleco the rearmost hole on the rib/skin to ensure a good fit. I then drilled the rear spar to the ribs. Now, the plans warns about the possible use of shims between the rib and rear spar. I made some out of 0.025" material, and sure enough it was very tight. I decided to go with a 'liquid shim' as I only needed 0.010" or so. (The Stewart S-51 plans have you use 3m structural epoxy as a liquid shim in places - so I think I can use this method on my project). 
 
 

Next order of business was to fabricate the spacers that get placed on the underside of the ribs. 
 
Simple enough to do but the trick was to match drill them with the holes in the rib. After a bit of head scratching I figured my best bet was to use the fan spacer and clecod 'do according to the holes that I could and that allowed me to use the last hole in the fan spacer as a drill guide for the hole I needed. Worked like a charm.

Lots of monkeying around and I spent more time than really needed, but oh well....it's a Sunday.

Finished riveting and proseal of the rear baffle - 2 hours

Pretty self explanatory. I finished riveting the nutplates on the rear baffle of the fuel tank. After back riveting the nutplates I put a dollop of sealant on the heads. Much cleaner than when I first started on the tank access.

Aerobatic fuel pickup installation - 2.5 hours

I used a syringe to put a dollop of sealant on all the rivet exposed rivet heads on both left and right rib #1 and the shop heads of the tank attach angles.


Next I had tapped up the fittings on the aerobatic fuel pickups to ensure that no proseal whould get inside. I slathered up the fitting and installed them in the tank.

After a good cleaning in MEK I gooped up the area with proseal and torqued the AN924 jamnut on. I spread out the proseal on the nut, cleaned it up and applied a dollop of proseal to the exterior tank attach rivets.

 Next I used q-tips dipped in MEK and started the long process of cleaning proseal off the aluminum fitting threads. Some final wipes with the cloth and then I could remove the tape.

Left rib #1 and tank attach angles - 6 hours

Big day today. I started the morning by installing the left rib #1. Once I had cleaned up the rib with MEK I had torqued the vent line to the rib fitting.

Next I needed to bend the opposite ends of the vent lines up to the high point of the tank. Took some  strength but I did it with use of my fingers to ensure that I didn't kink the line.

Both tanks are nearly done. All that is needed is to fit the tank attach angles. This part I am a bit worried about as in my mind it's going to be tricky.

Well straight off I can see that I will need to notch the attach angle to make room for the rivet shop heads. Little bit of grinding with the 3M wheel made short work of it.

Before I can set these in I needed some bucking partner help to arrive.

To kill some time I jumped over to the reinforcing ring on one baffle for the fuel sender. This is a bit tricky with the NAS nutplates as there is no room to get those rivets set. The squeezer was not going to work. After some head scratching I grabbed a back rivet set with a narrow collar and shaved down a side with the 3M wheel. It allowed me to make quick work of installing the nutplates by back riveting them.


  Well by the time I had that done, my friend mike arrived to lend me a hand on the attach angle installation.

He operated the gun and I operated the bucking bar. After coating all the pieces in a slathering of proseal. We set in to buck the rivets. Well...it went very well. Much better that I thought it would go.
 

Next on the agenda was to clean up the pieces so tomorrow I can install the fuel pickups.