After priming the rear spars, I temporarily clecoed them to the wing ribs (ensuring the main spar was not twisted), and then clecoed the doublers and hinge brackets to the rear spar.
I decided it would be easier to squeeze rivets in the doubler/bracket to spar attachment holes which were not also attached to the wing ribs, so after clecoing everything together on the wing, I removed the spar to rib clecos and clamped the spar on its side to the workbench. I also taped off holes not to be riveted so as not to make any mistakes.
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| Final fitting of the rear spar and attachment to the (left) wing ribs prior to riveting |
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| Right rear spar and attachements clamped to the workbench |
Squeezing the majority of the rivets was relatively easy, however there were a few that had to be bucked around the inboard aileron hinge bracket.
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| Bucking the rivets next to the inboard aileron hinge bracket. Easy using the longer 7" rivet set for clearance |
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| Inboard aileron hinge bracket riveted to the rear spar and doubler plate |
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| Inboard spar doublers riveted in place except for rivets that will attach to the wing ribs and flap hinge attach ribs |
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| Rear spar inboard shop heads. The 4-8 and 4-6 rivets were plenty long to form a good shop head |
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| Rear spar clecoed to wing ribs ready for remaining spar to rib rivets to be bucked. Holes that are not riveted at this time are taped off. |
After completing what I could rivet without the spar attached to the ribs, I clecoed the spar to the wing ribs and clamped the whole assembly as securely as I could to the workbench.
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| Wing assembly held securely on workbench with clamps behind the main spar. The rear spar overhangs the edge of the workbench for easy access to the rivets |
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| I clamped wood blocks alongside two of the ribs to prevent side to side movement of the assembly while riveting the rear spar to the ribs |
I chose to buck the remaining spar to rib rivets as there was enough room to comfortably hold a bucking bar in place. Squeezing may also have worked in a lot of places, but with less control due to rivet heads being in close proximity.
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| While setting rivets near the edge of the rear spar, I used the rubber tube trick to keep the rib flange flush to the spar during the initial set |
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| To set the flush rivet near the wing root I used a Boeing 3/4" flat/flush rivet set. This worked really well, and the Boeing rivet sets are my go to sets for AN426 riveting. |
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| All rivets set in the rear spar, with the exception of those that will later be used to attach the flap/aileron gap fairings |
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| Flap hinge doubler riveted in position |
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Flap hinge doubler shop heads
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| Flap/aileron hinge doubler and inboard aileron bracket riveted in place |
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| All shop heads formed well. Most of the rivets here were bucked. |
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| Aileron hinge doubler shop heads. The outboard most rib and aileron hinge bracket are not riveted at this time. |
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| Rear spars riveted onto both wing assemblies, and section 15 is finally COMPLETE |
Build Hints
- Doublers and hinge brackets can be riveted to the rear spar prior to attaching the spar to the main ribs. This makes it easy to squeeze the majority of the rivets, with the exception of those holding the inboard aileron hinge bracket to the spar which are easily bucked with a long rivet set. Just be sure to NOT rivet any rear spar to wing rib holes yet!
- The instructions specify riveting the inboard aileron hinge bracket to the rear spar last for improved clearance, however this is not necessary if you follow the previous hint
- When riveting the rear spar to the wing ribs, use wood blocks clamped next to two ribs to prevent any side-to-side movement of the ribs while bucking.
- All rear spar to wing rib rivets are easily bucked. Squeezing the spar to rib rivets may be possible, but I would only attempt it with a hand squeezer, and if given the choice, I prefer bucking those rivets.
- There may be some slight lifting of the rib flange when forming the shop head due to the thinner flange, but I was able to mitigate this by
- making sure clecoes were placed in each hole not riveted yet
- using a small piece of rubber tubing over the rivet shank when setting rivets closest to the top edge of the spar. This pulls the rib flange and spar together during the initial set. I did not need to use the rubber tubing while setting rivets closest to the bottom edge of the spar because I was able to place a cleco in the spar flange to rib flange hole (where the bottom skin will attach) to hold things tight.
Dates: March 23 - April 5 2024
Wing Rear Spar Total Time: 32.2 hours
RV-10 Build Total Time: 633.1 hours
Priming Total Time: 73.4 hours (not included in build time totals)
