Jun 26, 2022     16-04 - Top Wing Skin Final Items - (10.1 hours)       Category: 16 Top Skins

6/23/22 – 2.0h
6/24/22 – 2.8h
6/25/22 – 2.2h
6/26/22 – 3.1h

It's taken a couple thousand rivets, but I feel like I finally have a clue on successfully bucking rivets. The rivets aren't 100% uniform yet, but they all meet standards without drilling out and replacing multiple misfires or major dings in the assembly. Practice makes perfect, and I think I'll be pretty good at this by the time the airplane is flying!

This step consists of some final assembly items to complete the installation of the top wing skin. It starts by clecoing and then riveting the J-channels that run down the center of the skin along the complete span of the wing. The J-Channels slide into place pretty easily, and you have to make sure the outboard J-Channel sits above the inboard J-Channel. There is good access to buck the rivets, but pay attention to ensure the correct rivets get installed in the five holes where the J-Channels overlap. I used a couple of small nuts on the clecos to help pull the J-Channel tight to the skin before riveting, and was really happy with the way the parts end up riveted tightly together.

The last item in this step is to attach the outboard aileron hinge brackets. The holes for the spar and a couple of holes for the rib web are pre-drilled so the bracket assemblies can be cleco'd in place. There is good access to match drill the remaining three holes for the rib web, and then all of the holes are drilled to final size. The plans specify an extended #30 drill bit to final drill the holes in the aft spar to provide clearance for the hinge bracket assembly. The plans remind you to remove the hinge brackets, debur the holes, and cleco the brackets back into place before riveting.

Riveting the hinge brackets to the aft spar and outboard rib isn't as straight-forward as it looks. I thought I'd have relatively easy access to use the pneumatic squeezer. My plan was to use the squeezer to put the manufactured head on the inside of the wing rib first, leaving clearance for the manufactured head of the rivets to go on the outside of the assembly to the rear spar. I actually managed to get the bottom-most rivet on the rib squeezed (you can see the shop head on that one in the picture), but I think I was lucky to get that one done cleanly. The squeezer really does not have the required access to this area, and good luck if you have to drill out one of those rivets from inside the rib cavity! I switched to the rivet gun and bucking bar to set the rivets with the manufactured head on the outside of the assembly to the wing rib. I needed an extended rivet set, just like I needed an extended drill bit, for the rivets to the aft spar. A double-offset rivet set would also work in this area. I had to replace one of the rivets, but it came out cleanly and the rivets all went in without any other drama.
[3x Rivet Gun, Swivel Mushroom Set, Regular and Extended1/8” Cupped Set, Tungsten BB-7 and BB-11 Bucking Bars, Pneumatic Squeezer with 1/8” Cupped Squeezer Set]

  Jun 12, 2022     16-03 - Top Wing Skin Installation - (25.8 hours)       Category: 16 Top Skins

Initial Prep (Debur, Trim, Drill, and Cut)
5/12/22 – 1.4h
I took another look at the forward wing walk doubler on the right wing after reading another build log about how their doubler was just a bit long and over-lapped the main spar. My doubler had a very slight overlap as well, so I took a few passes with the file to just remove the overlap. That won't make a huge difference, but might help the forward edge of the skin rivet tighter to the spar without creating a crease. It was also a good way to procrastinate before starting to rivet the top skins to the ribs and spars. Riveting always makes me a little apprehensive, so I like to look busy even though I'm really not!
[Flat File, ScotchBrite Pad, Primer for Touch-Up]

Assemble
5/13/22 – 3.3h
5/16/22 – 1.0h
5/17/22 – 1.3h
5/18/22 – 2.7h
5/30/22 – 1.1h
5/31/22 – 1.0h
6/1/22 – 1.2h
6/2/22 – 1.8h
6/5/22 – 1.7h
6/5/22 – 3.0h
6/8/22 – 1.1h
6/9/22 – 1.3h
6/10/22 – 3.1h
6/12/22 – 2.2h
First, a huge shout-out to Greg for his invaluable help on both the right and left wings! Greg is a new RV-14A builder, and volunteered several hours to help me set most of the rivets forward of the J-Stiffeners on both wing skins. My arms are not long enough to buck all the rivets toward the leading edge myself, and Greg's help was essential! It was a great learning experience for both of us, and the rivets we set as a team came out great! Thank you!!!

I placed the wings with the forward spar down on folded saw-horses on the floor. That provided access for bucking the rivets by reaching over the rear spar for most of the rivets on the wing. I started in the center of the wing and worked my way up and down each rib toward the wing root and wing tip. I attached the inboard skin first, and then used the center-out method on the outboard skin. A small rectangular tungsten bucking bar worked well for almost all of the rivets with pretty good results. Things get a little tight near the rear spar, so I had to go with a bucking bar with an angled face for the last two or three rivets on each rib. I also used the angled face bucking bar on the rivets closest to the rib doublers for the flap hinge brackets. It is very tight in those areas, and things definitely slow down there. I did end up with a couple of cosmetic blemishes near the rear spar due to the awkward access bucking the rivets myself – lessons learned for the left wing!

I used the pneumatic squeezer for the rivets along the root rib. Those rivets are very easy to access with the squeezer, and there isn't a lot of surface area there for a large rivet gun flush set. The root rib has several nutplates, which leads to a lot of layers including the nutplate, root rib, wing walk doubler, and wing skin. I set the rivets without the nut plates first, then adjust the squeezer to set the rivets on the nutplates. I tried a new technique to help protect the screw hole in the nutplate while squeezing the rivets. I inserted a 1/8” cleco into the screwhole to prevent inadvertently damaging the nutplate with the squeezer. The cleco essentially acted as a guard rail for the squeezer, and I installed all of the nutplates without any damage.

I finished the wing skin by riveting the lap joint between the inboard and outboard skins, and then the rivets along the rear spar. I was very happy with how well the rivets pulled the ribs and skins together, and the really tight fit between the skin and forward spar as well as along the lap joint. I had the edge-break on the skins dialed in really well – just a very slight (almost imperceptible) break ended up with a really tight fit.
[3x Rivet Gun, Tungsten Bucking Bars (BB-6, BB-7, and BB-11), Pneumatic Squeezer with Flat Squeezer Set]

  May 08, 2022     16-02 - Top Wing Skin Preparation - (40.2 hours)       Category: 16 Top Skins

Initial Prep (Debur, Trim, Drill, and Cut)
3/8/22 – 1.6h
3/12/22 – 0.9h
3/27/22 – 2.0h
3/28/22 – 1.9h
3/29/22 – 1.6h
3/30/22 – 1.4h
3/31/22 – 1.9h
4/1/22 – 2.1h
4/2/22 – 0.8h
4/15/22 – 0.9h
4/16/22 – 0.7h
4/17/22 – 1.2h
4/18/22 – 1.0h
4/21/22 – 0.5h
5/1/22 – 1.0h
Preparation of the top wing skins started by clecoing the inboard skin and wing walk doublers to the main and rear spars and the wing ribs. I have not installed the rear spar yet, and I don't plan to do any of the match / final drilling until the rear spar assembly is complete. Clecoing the skins in place at this stage is valuable, though, to ensure all the skins are oriented and marked correctly. For example, it is possible to install the aft wing walk doubler upside down. The aft wing walk doubler has two holes near the aft edge that are ignored on the RV-14. Those holes provide a valuable clue to the doubler's orientation, which I learned as I removed the top skin and noticed the doubler was face down with the holes near the forward edge! I flipped the doubler over to the correct orientation, and then used my Sharpie to make sure it was labeled for correct installation later.

The parts for this step are probably the easiest to edge-debur that I've come across so far. No flanges, no facets, no curves – just long, straight edges. I deburred the wing walk doublers, inboard skins, and outboard skins, and then cleco'd the inboard skin and wing walk doublers to the spars and ribs to set up for drilling. I also finished deburring the left and right upper J-Channels.

There is some match-drilling for the nutplate rivet holes along the inboard edge of the inboard wing skin and wing walk doublers, as well as final drilling for the nutplate screw holes. All of the #40 holes common to the inboard wing skin and wing walk doublers are also final drilled.
[Hole and Edge Deburring Tools, #40 Drill, #19 Drill]

Final Prep (Dimple, Countersink, and Shape)
4/2/22 – 0.9h
4/15/22 – 1.8h
4/16/22 – 2.2h
4/25/22 – 0.9h
4/26/22 – 0.6h
4/27/22 – 1.5h
4/28/22 – 1.3h
4/29/22 – 0.9h
4/30/22 – 0.9h
5/2/22 – 0.7h
5/3/22 – 1.6h
5/5/22 – 0.9h
The holes in the top inboard wing skin that correspond to the wing walk doublers are countersunk rather than dimpled. The plans state that countersinks up to .005” too shallow are preferred to countersinks that are too deep, so I backed off my countersink cage setting to leave the countersink about .002” too shallow. Countersinks that are too deep could enlarge the holes in the top skin. The rivet heads will sit just slightly high, but that won't be noticeable after the wing walk anti-slip material is in place and may end up nearly flush after the rivets are set.

There is a step on this page of the plans that I'm not a huge fan of. The plans specify thinning the inboard and outboard wing skins where the overlap near the forward edge to be flush with the .032” fuel tank skin they butt up against. The inboard skin is .032” and the outboard skin is .025” for a total thickness of .057” where they overlap. My plan was to thin each skin to approximately .016” with a gradual thickness taper toward the corner of each skin. The problem with this step is it requires a lot of trial-and-error test fitting, which isn't easy with the relatively large skins; and if you go too far, the skins are ruined. I started with the flat file to get the skins closer to the desired thickness, then switched to the Dremel, Scotch Brite Wheel, and 220 grit aluminum oxide sandpaper to work the taper and get the final thickness. It is a very time-consuming process. I got the skins close to the required thickness, but left them just a little thick to avoid accidentally tearing through the skin. The skins get pretty thin and fragile around .018” thickness.

The final preparatory steps are to put a slight edge break in the leading edge of the inboard and outboard wing skins to help them rivet tight to the forward wing spar, and along the inboard edge of the outboard wing skin to help it rivet tight in the lap joint with the inboard skin. The top flanges of the wing ribs, other than those that sit under the wing walk doublers, also get dimpled at this stage. You could actually dimple the rib top flanges (like the bottom flanges) before the ribs are attached to the forward spar if you are confident of not accidentally dimpling one of the ribs under the wing walk doublers. If not, dimpling is easy enough with a squeezer at this stage of the build.
[Microstop Countersink Cage, #40 Countersink Cutter; Dremel with sanding barrel bit, 2” ScotchBrite Wheel, Flat File, Edge Forming Tool (Vise Grip Style), Hole and Edge Deburring Tools, 22” C-Frame with #40 Standard Diameter Dimple Dies, Pneumatic Squeezer with #40 Reduced Diameter Dimple Die]

Prime
4/11/22 – 0.5h
4/14/22 – 0.8h
4/24/22 – 1.0h
4/27/22 – 0.5h
4/29/22 – 2.5h
5/2/22 – 0.7h
5/8/22 – 0.5h
I decided to try a different brand of primer. The Dupli-Color primer prices are going up, and I ran across a can of Rust-Oleum Self Etching primer that was about 30% - 40% less. The spray tip on the Rust-Oleum is not quite as precise as the Dupli-Color, so the paint goes on thicker and dries with a rougher (powdery) texture. I used a ScotchBrite pad to smooth the painted surface after the primer dried, and I was very happy with the smooth, thin, and apparently durable finish. I have not subjected the primer to the duct tape test, yet, but I plan to make the switch to the new primer.
[Grey ScotchBrite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Dupli-Color Self-Etching Automotive Primer (Green – Rattle Can), Rust-Oleum Automotive Self Etching Primer (Green – Rattle Can)]

  Mar 27, 2022     16-01 - Top Wing Skins (Plans) - (1.0 hour) Category: 16 Top Skins

3/6/22 – 1.0h
The primary internal wing structure is complete, so on to the top skins! This section of the plans is only four pages long and consists of attaching 5 parts to each wing. The previous section of the plans was also just four pages and 8 parts, which took nearly 40 hours to complete! I won't get trapped into thinking short = quick!

I did not see any Service Bulletins, Notifications and Letters, or Revisions and Changes for this section on the Van's support page that would change the plans or parts I received in the wing kit. My review of the plans for this section revealed a couple interesting items. First is the requirement to remove some material thickness from the leading edges of the top skins where they mate so that when joined, they are the same thickness as the 0.032” fuel tank skin. That will be a file, sand, fit, and repeat process until the parts fit together nicely at the right thickness. The other item of note is the long and short J-Stiffeners that were prepared a few steps ago are inserted into the assembly at this point and riveted to the top skins. That will require a look back at the previous section to make sure I get them oriented correctly. It also seems strange to rivet the skins to the ribs first, then insert the J-Stiffeners and rivet them last. I'll have to look at that closer to see if I can figure out why that is the order of those steps in the plan.