Riveting leading edge and main skins

May 17th and 18th, 19th 25h

In order to move ahead with riveting the leading edge and main skins.  we needed to fix a couple things.

  • One of the countersink did not go well in the main spar.  I took a very conservative path fixing  this.  I filled the hole, re-drilled and re-did the counter sink.  In addition, I added a doubled to reinforce the 10 holes around the fixed countersink.  As well, I added an angle to attache the rib to spar via 4 holes instead of 2, which reduces the load in the hole with the fixed countersink.
  • The most inboard rib in the leading edge ended up having holes too close to the edge.  I took the conservative oath here as well.  I ordered new ribs and I re-did the work.  The new ribs look great.

Then I moved on to last items in the leading edge and the main spar, before riveting everything together, the point of no return:

  • I finished installing the stall horn with the new hardware and riveting it to the leading edge.
  • I torqued the tie down assembly to spec

Afterwards, I finished fitting all the main skins, the leading edge and the fuel tank.  Everything fit together great.

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Then, after checking that everything looked great, we went on with the riveting of the leading edge and main skin.

First, we riveted the new inboard ribs to the leading edges.  This went great.

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Then we moved to rivet the leading edge ribs to main spar.  There is two issues here.  One is that it is very hard to reach the rivets in the middle ribs with the bucking bar, Van recommends using LP4 pulled rivets here.  The other is that the ribs from the main spar get in the way of the rivet gun.  We started by riveting the ribs that we can access with an offset rivet set, but there was still a small angle that leads to the head of the rivet gun hitting the main spar.  So, it looks like going with LP4 rivets for all the ribs from leading edge to main spar is the way to go here.  But we are holding on doing these until we confirm with Vans.

Then we moved on to riveting the leading edge skin to the main spar.  This went on very smoothly, especially given that we can use the pneumatic squeezer here.  The results looked great.

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Afterward, we went to riveting the skin to the main spar and skeleton.  We started with W702, moving from the center to outwards as recommended.  This went very smoothly and the results looked great.

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Riveting leading edge, prepping riveting main skins

May 11th and 12th, 11h

After all the prep work and the priming, we are finally at the last stage of riveting the wing together: the point of no return.

So, before we get into riveting and finalizing the wing, we need to think of all the wiring, lights and avionics components that go into the wings.  This drove into a lot of research last week, these are the current options under consideration:

  • Heated pitot with Aoa: Dynon or Garmin.
  • Avionics: the choice of pitot tube will determine the choice of the avionics, given that I would like to go for a fully compatible system.  The current choices are Dynon or Garmin or AFS.
  • Stall warning:  I am going for the choice provided by Vans, the stall warning will provide redundancy since I have as well AoA with the pitot tube that would be integrated with the rest of the avionics.
  • Light:  most likely FlyLED, the open question is the position of the landing and taxi light in the wing tip and how would that be for lighting the runway and taxi way.  The other option is AeroLED.

We are still in the middle of making some decisions.  In the mean time, we went ahead with riveting the leading edges. It was great to see both leading edges coming together in one day, when it took weeks to do the fuel tanks.  Riveting without fuel tank sealant is so much more rewarding. The two leading edges look great:

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After riveting the leading edges, we went into installing and riveting the stall horn.  It came together well.  However, we broke one of the bolts, so we can not rivet it for the the time being:

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Then we went on prepping the main skins for riveting:

  • Leveling the wings to ensure that there is no twist.
  • Removing some the vynil paper that was not finished.
  • Attacking the skins.
  • putting rivets.
  • Adding tape.

One of the wings main skins are ready to be riveted:

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Priming wings skins and leading edge

May 10th, 7.5h

First, I need to finish the last steps of the priming preparation:

  • Applying alumina prep
  • Rinsing
  • Applying acetone

Then I went ahead with priming:

  • Both leading edges
  • One remaining rib from each leading edge
  • join plate between leading edge and fuel tank
  • All the top skins
  • All Access plates
  • The of the main spar, back spar and ribs.  These need to be primed to protect the areas of the countersinking and dimple cleaning.

Prepping wing Skin for priming

May 5th, 4h

I decided to go ahead and prime all wings skins and leading edges on same time.  So, it is going to be a big priming job.  First, I decided to prep all the parts so that I can actually tackle the priming job in one day.  So:

  • I remove the inside venyl wrap from all skins and leaded edges.
  • I rough the inside surfaces for all skins and leaded edges.
  • I washed all the surfaces

Next is to apply Alumina Prep, Wash, clean with Acetone, and finally Prime.

More Skin Prep

May 4th and 5th, 11h

  • Installing nut plates in the join plate between the fuel tank and leading edge: drilling, deburring and riveting.
  • Cleaning the dimples in the back spars and ribs to get more flush rivets in the skin, for both wings.
  • Counting winking the main spar for both wings.
  • Deburring leading edges for both wings.
  • Dimpling leading edges for both wings.
  • Deburring all the ribs in the leading edge for both wings.
  • Dimpling all the ribs in the leading edge for both wings.
  • Installing nut plats for the stall horn system: drilling, deburring and riveting.
  •  Smoothing the transition between the fuel tank and the skin, where the 2 skins overlap.

More Skin Prep

April 15th, 20th, 28th, 10h

While Riveting the fuel tank with the sealant, I took some breaks from the sealant to get some progress as well with the rest of the wing.

  • I Deburred and dimpled the upper skins of right wing
  • I dimpled the skeleton of the left wing.
  • I dimpled the back Spar of the left wing
  • I deburred and dimpled the skeleton of the right wing.
  • I smoothed the edges of the upper skins.
  • I dimpled the back spar for the right wing.

Riveting/Sealing Fuel drain, caps and Ribs

April 11th, 14th, 18th, 20th, 21th, 22nd, 27th and 28th, May 2nd 47h

Riveting the fuel tank ended up taking a lot of time.  The procedure of the riveting is very similar to the one of the stiffeners.

On April 11th, I riveted the fuel drain and caps with back riveting, for both tanks.This took about 6h.

On April 14th, we did two ribs. This took about 4h.

On April 18th, we did one rib. This took about 2h.

On April 20th, we did two ribs.  This completed the left tank inner ribs. This took about 3h.

On April 21th, we did five ribs.  All of the right tank inner ribs at once.  We definitely improved and speeded up our process.  We learned that it is more efficient to do multiple ribs in the same time, so we tackled 2 together, then we tackled 3 ribs at a time. This took about 6h.

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On April 22nd, I prepared the 2 outboard rib.  I had to custom cut a 6D rivet to fill the holes in the rib, then rivet it with sealant.  Then, I prepared the reinforcement plates, drilled then and riveted then with the sealant to the outboard ribs for both tanks.  Then, I roughed all the surfaces for all inboard and outboard ribs and the rest of the parts that mount to the inboard ribs. This took about 5h.

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Then, I did couple little side tasks, which took about 3h.:

  • Testing the fitting of the 2 tanks with the baffle and the z bars, now that the ribs are riveted.

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  • Priming the z bars, so that they are ready to rivet to the tank once the fuel tank is complete.

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On April 27th, I riveted the outboard and inboard rib for one of the tanks.  The riveting was easier since it can be done with the pneumatic squeezer, so it can be done with all one person. This took about 6h.

On April 28th, we riveted the outboard and inboard rib for the other tanks. Then we riveted the horn and reinforcement plate for both inboard ribs.  This took about 3h.

Then we moved on to the vent line, fuel pick up tube and fuel sander.  We started preparing the vent line, but then we realized that we need to flare the pipe, and I did not have a flaring device.  So, we decided to move on until I get one.  Then we look at the fuel pick up tube, we went though the instruction of creating the custom one, but then I decided that getting an upgrade from Vans with the mesh is a better option, so we decided to move until I purchase that one.  Then we move on to the fuel sander, for which we riveted with sealant the plate nuts, for both tanks.  This took about 3h.

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On May 2nd, I took on the task of examining the flushness of the rivets and cleaning all the outside fuel tank sealant around the rivets.  The left tank, which was the first one we did had way more tank sealant around the rivets and it took about three hours to clean. The right had way less fuel tank sealant and took only about an hour to clean.  Then I went through both tanks marking any rivets that were not smoothly flush with the surfaces and sanded those rivets to get a nice flush finish.  A couple of rivets were a little too high for sanding according to the MIL specs, so I removed those rivets in order to reset them.  Afterwards, I added protective tape to keep the metal protected against corrosion until it gets painted. This took about 6.5h