Rudder assembly Part 2

January 12 – February 4: I had been putting this task off as I was apprehensive about riveting the trailing edge and keeping it straight. As it turns out, the double flush riveting was easier than I thought it would be and the finished trailing edge is pretty dead-on straight.

Having a flat surface is essential, and my EAA1000 workbenches are good in that aspect. But in order to help it a bit more, I used a leftover Formica kitchen countertop that I had been holding onto from our last house. And I went to Home Depot and picked up a 1-1/2×1-1/2 inch piece of steel angle. My original thought was to match drill the trailing edge to the steel angle, but decided against it as overkill, so I just used it to enhance the flatness of the countertop.

I was going to follow Van’s instructions and use the double-sided tape method, but had spoken with other local builders who mentioned that they had some adhesion issues with the tape. So while we were in San Diego in December, we made a side trip to Aircraft Spruce in Corona and I picked up a pint kit of tank sealant, among other items.

I put down some painters tape to keep things from getting too messy and then match drilled the trailing edge directly into the bottom surface of the MDF countertop. I mixed up the first batch of tank sealant and then clecoed the right rudder skin and trailing edge wedge directly into the MDF surface after applying a very thin layer of tank sealant. Mating surfaces were scuffed with 150 grit sandpaper and cleaned with acetone and then 91 percent isopropyl alcohol and allowed to dry thoroughly.

This assembly was then allowed to sit for a week (Sunday to Sunday) to cure. The angle was clamped to the edge of the countertop just to serve as an additional source of flatness.

After curing a week, now comes the part where you need four hands. I mixed up another batch of tank sealant, then applied a very thin layer to the upper surface of the trailing edge wedge and clecoed the lower corner into the workbench as described in the instructions. Here’s where the MDF countertop was an inadequate surface for what was to follow.

I don’t have photos of this process, as we both had our hands full. The “upper” (left) rudder skin is fixed at the bottom trailing edge corner and then is rolled downward onto the tank sealant, clecoed to the benchtop, and the stiffeners are blind riveted to the shear clips attached to the “lower” skin, gradually rolling the skins together.

With all the movement entailed at the beginning of this process, the lower 10 or so holes in the MDF hogged out and wouldn’t hold a cleco. In hindsight, I should have used a piece of aluminum angle, which I happened to have around. To compensate, I used a piece from the trim bundle that Vans throws into the kit as a makeshift clamping surface to allow the clecos to grip. Not the best solution, but it worked out fine.

To ensure that things stayed together, I used some bucking bars, hammers, lead counterweights and an exercise weight (wrapped in tape) to hold the skins at these lower holes together a little better for a couple of days. The upper set of holes seemed to hold up better, and these stayed clamped much better.

I allowed this completed assembly to cure for a full two weeks just to make sure. In the meantime I cut out the foam trailing edge ribs and started work on the tailcone pieces listed in 10-02 and 10-03. I also fabricated the F-01411D HS attach bar support. These were all completed, deburred and are ready for primer as soon as it warms up enough.

After putting it off long enough, I decided to dive into the double flush riveting that I had been dreading. I took my back-riveting set to the garage and clamped it into the vise and drove the roll pin out with a drift punch. This left me with a small diameter flush rivet set.

Following the instructions, I assembled the rudder spar assembly into the completed skins with no issues. I then riveted the skins to the spar using the squeezer as much as possible. The last few rivets on the bottom had to be driven with the gun as the yoke I have isn’t deep enough.

I put a strip of painter’s tape down the trailing edge then labeled the holes 1 through 10 and then repeating. I also taped the edges of my back riveting plate to avoid scratching, even though I have already rounded them off and polished them.

Now for the task I had been apprehensive about. I loaded the holes with rivets, applied rivet tape and flipped it over. Starting in the center, I partially set every tenth rivet following the instructions in Section 5. After the first few, I started to get the hang of the process, starting perpendicular to the back rivet plate, then smoothly pivoting to perpendicular to the trailing edge wedge in one motion. After each round of rivets, I eyeballed the trailing edge to ensure it didn’t start creeping out of straightness. So far so good.

After getting all the rivets 90% set, I went back over the trailing edge and finished setting them in the same every-tenth pattern, checking for straightness along the way. I ran my fingers along the rivet line, finishing any that felt like they were proud of the surface more than others. The final results turned out better than I expected. I suspect the tank sealant and the leisurely cure time helped keep everything together well during the riveting. Nothing shifted at all. Any tank sealant that squeezed out was cleaned up with acetone, and the rudder was put on the shelf with the other mostly-completed parts. On to priming the elevator and tailcone parts and waiting for spring. In the meantime I am starting on a PVC tubing spray booth in the garage.

Finishing Horizontal Stab

November 9-16: After clecoing in the 905 nose ribs, I riveted them into place. Then the completed front spar/interspar assembly was put into place and clecoed in. Skipping every other hole, I still managed to run out of silver 3/32″ clecoes. I ended up working from one side to the other, moving clecoes to the other side as I completed a section.

Once things were clecoed into place, I began riveting the skins to the flanges of the rear spar, then riveting the skins to the interspar ribs up to the stringers. Then the skin was riveted to the stringers on each side, then the remaining ribs were riveted to the skins. I used the tungsten bucking bar and flush set on the rivets that I couldn’t reach with the squeezer.

I had to drill out a couple of rivets whose shop heads were overdriven and flattened out. And looking back, I should have started riveting the skin on the bottom side of the HS, as the first part of the rivets set resulted in some skin “lumpiness” that I’m not too pleased with. The second side turned out better once I had more practice.

I did finally get in contact with my assigned MD-RA inspector, who informed me that every rivet must be visible in response to my question of how far could I assemble. So again, I will leave the rear spar clecoed into place, and the two inboard HS-905 nose ribs will be left out to allow a clear view of rivets in the front of the horizontal stab. So for now, I’ve put the partially completed assembly on the shelf, but will finish the front spar to nose rib blind rivets once I pick up my swivel nose rivet puller I ordered from Aircraft Tool. There is simply no room for a regular rivet puller when trying to pull those dozen rivets.

Update: After checking in with the Flight Chops RV-14 build here at the CH2A hangar, and recalling what my inspector told me, I decided to finish riveting in the rear spar into the HS. The rule is that every rivet needs to be visible. With the lightening holes in the rear spar, you are able to see all the rivets.

Dimpling HS skins

November 5-6: I taped off the hole locations that remain open, and then dimpled the HS skins. Edge holes were done with the pneumatic squeezer, and the remainder with the c-frame and a hammer.

I clamped the HS cradles to the workbench and inserted the dimpled skins. The cradles were fabricated with plywood from the crate that the kit shipped in and some 2x2s from Lowes.

Then I clecoed the HS-905 nose ribs into place (two on each side), riveting will wait until tomorrow.

Riveting vertical stabilizer

November 4: riveted the VS skin to the skeleton. I wrapped the tungsten bucking bar in hockey tape to try to keep the scuffing to a minimum. Got it all completed in one session. All but the front two rivets on the VS-706 tip rib. There’s no room to get a squeezer or bucking bar in there, so it looks like I’ll have to fabricate something to be able to get those last two done.

And the rear spar is clecoed into place for now. Because Canada requires a pre-closing inspection, no parts of the structure can be enclosed beforehand. So I’ll have to leave the VS (among other parts) incomplete until I get enough done to have the inspector come out. This would probably include the VS, HS, possibly elevators and rudder, wing bottom skins and the bottom of the fuselage under the floor panels.

More Horizontal Stab and the Pneumatic Squeezer arrived.

So in the last post I mentioned that I needed to order a longeron or flange-nose yoke for my Main Squeeze squeezer from Cleaveland Tool. I got on their website Monday to order and realized that my arms and shoulders were still hurting from using the manual squeezer. So I took the plunge and bought their pneumatic squeezer kit. I emailed Mike and asked if they could substitute the flange-nose yoke for the 3″ yoke that comes standard with the kit, as I already had the yoke with my Main Squeeze. Mike emailed me back right away and said it was no problem. I completed the order with Annette, and everything arrived Wednesday. I’m 4 for 4 on great service by Mike, Annette and the rest of the crew at Cleaveland!

After getting things set up last night (Friday) I had a cinch job of finishing up the rest of the rivets in the front horizontal stabilizer spar thanks to the new squeezer. I’m looking forward to more rivets to squeeze.

I also countersunk the 400+ holes in both spars and the stringers and prepped both skins today with Prekote and maroon Scotchbrite. Prekote says to prime aluminum within 24 hours of prep, so I’ll warm up the garage first thing in the morning and prime the skins inside and out. And then use the leftover AKZO and a Q-Tip to touch up all the countersinks I made on the spars and stringers.

And my Amazon-provided torque wrench also arrived on Thursday, so I finished bolting the elevator center hinge bearing bracket onto the rear spar, then torque sealed it.

Moving the shop and assembling Horizontal Stabilizer

It’s starting to get too cold to spend a lot of time in the garage working, so we moved the two smaller EAA 1000 workbenches and assorted tools to the basement. I may leave the compressor in the garage due to noise and just run the air hose through the shared wall and into the basement.

I’ve been able to do all my structure riveting so far with my Cleaveland Main Squeeze, which has been worth every penny. BUT. I finally ran into a stopping point with the HS skeleton. The yoke that came with the squeezer is not suitable for riveting around the spar this time. So I’ll need to order a longeron yoke first thing Monday, which means I’m on hold with this portion until it arrives.

Still have plenty to work on, including deburring and priming the skins, and countersinking the two spars and stringers. Hope the weather cooperates for the priming.

Priming Horizontal Stabilizer

October 20: Cleaned all the prepped HS parts with Prekote and plenty of water. Then mixed up another batch of AKZO and primed everything. There were so many parts this time I have to wait to do the skins later.

I had the pieces a little too close together, and had to go back later and touch up some thin spots.

Rudder assembly Part 1

September 23 and 29: Continuing on with assembling the rudder after priming.

Had another of what I thought was an “oops” moment when I saw that I placed the shop head of rivets on the rudder spar on the side of the thinner metal. I took pictures and emailed Vans support asking if I needed to drill these out and replace them.

Sterling replied that the manufactured/shop head standard is not mandatory, as universal head rivets have the same strength no matter the head orientation, and to build on.