More Rudder Work – 5 hrs

First step today was to align the R-918 rudder bottom attachment strips and clamp them in place. Then I drilled through the skin, rib and attachment strips. Then I drilled out all the remaining holes in the rudder to final size.

Then I went to Home Depot and bought two 3/4 x 3/4 x 1/8 inch thick aluminum angles 4 feet long each to prepare for the dreaded trailing edge riveting. I ordered a small amount of Pro-Seal from Vans last week which I’ll need for the recommended pre-bonding process.

Then I removed the skins from the rudder. Staring with the right skin, I aligned the angle to the edge of the skin and clamped it on. Then I match drilled the angle to the skin along the trailing edge. This was time consuming because there are 46 holes and it put quite a load on my air compressor. I had to stop part way through to give it a chance to cool down. For the left skin I just drilled slightly into the angle at each hole then transferred the angle to the drill press and finished drilling each hole to minimize the load on the air compressor. Here is the angle all match-drilled and installed on the right skin.

Then I came to that dreaded line in the instructions that says, “dimple the skin, spar, and ribs”. Such a short instruction but so much work in hidden in that line. I deburred the edges of the left skin and used scotchbrite to buff up the inner surfaces where I will apply primer. Then I set up the DRDT-2 and dimpled the skin, spar, and rib holes. That was followed by a wipe down with MEK and a shot of primer around the perimeter. I used a piece of cardboard to mask off the stiffeners and other areas I didn’t want to prime.

Thirty minutes later I removed the inner blue film and here is the finished left skin ready to install. Looks nice, no?

Now I just need to do the same thing for the right skin and start working on the ribs, spar, and other skeleton parts. That will have to wait until tomorrow.

Building Up the Rudder – 6 hrs

This post is for Saturday Feb 27, 2010

Today was a little erratic since there were three different subcontractors in my house working on the kitchen while I worked on the rudder. My productivity was slammed since I was frequently breaking off to check on them or answer a question. But I made decent progress anyway.

I started by back riveting the stiffeners on the right rudder skin. I like this process because it produces almost perfect rivets on both sides and the process is pretty fast. My back rivet plate is a little short so I had to keep checking to make sure I wasn’t working near an edge because I have read about the nasty results if you shot it off the edge on other web sites.

Here is one stiffener after riveting.

And here it is after all the stiffeners on this side were installed. Pretty painless.

Next I started piecing together the skeleton. There is the usual clecoing of spar to ribs and I match drilled through the R-904 rib for one of the hinge bearings I also had to cut and trim the R-405PD rudder horn to make it fit (per the drawing instructions). I’m guessing this part is used in different forms on different kits and each is modified by the builder. But I could be wrong. Anyway, the modification was easy with the snips and the belt sander. I tried to minimize the material removed to make sure maximum edge distances were retained.

The instructions say to radius the end of the R-405PD rudder horn if necessary to make it fit nice and flat against the flange of the R-904 rib. I have learned that whenever the Vans plans say “if necessary” you can pretty much count on it. I used the belt sander and the scotchbrite wheel to cut and smooth the edge of the part. You can see it here.

Then I cut out the R-917 shim from stock provided in the kit. Be careful here. There is one strip of material provided for the R-917 and the two R-918s with only about 1/2 inch of excess length. If you make a mistake cutting a part you may be waiting for Vans to send you a replacement part. Anyway, after measuring twice its just a straight cut and trim to length. Then I assembled the horn to the spar with the shim and R-904 rib as instructed and drilled the holes in the shim.

That clamp with the sticker still on it was a $6.99 bargain at Harbor Freight Tools. I picked up two Thursday night on the way home from work. Those things are about $18 each at Home Depot.

Then I cleco’d the reinforcement plates onto the spar and fluted the R-903 and R-912 ribs to make them straight and true and cleco’d them onto the spar and match drilled the holes to the spar.

Then I installed the R-913 counterbalance skin and match drilled the holes to the ribs and spar. That skin is a tight fit. I had to work it a bit to get it on.

Then I put the right skin on to make sure everything lined up properly. I found that the notch in the skin for the R-405PD rudder horn was a little too narrow so I widened it with a pin file. It didn’t take much to get it to fit.

Then I jumped back to the stiffeners for the left side skin which I didn’t finish preping last night. The same process as before except I didn’t want to wait over night to install them so I primed with Dupli-Color self etch then warmed them with a small electric heater blowing across the ribs to a toasty 80 – 90 degrees F for a half hour or so. That stuff dries fast as it is but the warm air really kicks it over.

Then I back riveted the stiffeners onto the left skin and cleco’d it onto the skeleton with his brother.

Preping and Priming the Rudder Stiffeners and Skins – 2.5 hrs

This post is for Friday Feb 26, 2010

Tonight I got home from work and started preparing the rudder skins and stiffeners for assembly. I learned on the horizontal stabilizer that you have to be careful scotchbriting the inner surface of skins that are dimpled because the mere act of scrubbing the dimples can over-deburr them and cause the holes to enlarge slightly. So this time I scrubbbed the inner surfaces of the skins with scotchbrite before I dimpled. I then cleaned the surfaces with MEK and shot a light coat of NAPA 7220 primer along the rivet lines.

This prep is just for the stiffeners. There will be another round on prep for the remaining surfaces later.

Then I scrubbed one set of stiffeners with scotchbrite and Simple Green and rinsed thoroughly. I dried the parts then  laid them out for a half hour or so to air dry in case there was any residual water. Then I applied several light coats of Dupli-Color sefl-etching primer. Only time for one set tonight.

Why am I using NAPA 7220 on the skins and Dupli-Color on the other parts? Stupid consistency I guess. I was only able to find one can of 7220 at NAPA so far and I don’t really want to have one rib gray and the next one green so I used the NAPA on the insides of the horizontal stabilizer skins where you can’t really see it anyway. I’ve stuck with that process since then and it works. I plan to switch over to the Stewart Systems EkoPrime and EkoEtch products as soon as I get a good spray system set up. The rattle cans are OK but some spray on very nicely and others are not as uniform. It seems to vary with the nozzle.

Making Stiffeners and Match Drilling – 4 hrs

Today I made stiffeners for the Rudder. There are a total of 16 in 8 different lengths. My technique was to cut the stock material to length with snips, mark the profile of the tapered end with a Sharpie, rough cut the taper on the band saw, finish shape on the belt sander, and smooth the edges with the scotchbrite wheel. The first couple were slow, but I got faster as I went. Here is a view of the sixteen finished stiffeners on the left rudder skin.

By the way, the little notches Vans puts on the angle stock to tell you where to trim really do save time.

Next I laid the stiffeners out on the skin and match drilled #40. I marked each stiffener with L1 – L8, or R1 – R8 to make sure I can match them up the same way later. Here is a shot of the match drilling process.

Then I removed the blue film from the left rudder skin to prepare for dimpling and deburring. This is one of my least favorite parts of the building process. I could skip it and just remove the film completely but I really like to preserve the pristine look of the skin during the assembly process and leaving the film intact on most of the skin helps. But it is time consuming. It took over an hour to remove the strips from both sides with a soldering iron. Here is what it looks like. I still need to so the same thing to the right side skin.

Hanging the Horizontal Stabilizer – 1 hr

I picked up some straps and hooks from Home depot to hang the horizontal stabilizer from the ceiling of the garage to reduce the risk of accidental damage. At least we won’t trip over it or drop something on that smooth shiny skin with it up there.

Finishing the Vertical Stabilizer – 4 hrs

I didn’t have a chance to post it but the other night I cleco’d the skin onto the front spar and ribs of the vertical stabilizer.

This morning Rosie (Denise) and I riveted the interior rivets along the front spar and VS-707 rib of the vertical stabilizer using the same technique we used on the horizontal stabilizer. The task went quickly and I had to only drill out and replace one rivet that didn’t sit flush on the countersink.

Then I squeezed the perimeter flush rivets to the skin and pop riveted the rear spar to the VS-707 rib.

Here are a couple shots.

That’s two down and four more assemblies to go on the empennage.

Back on the Vertical Stabilizer – 2.5 hrs

With the horizontal stabilizer done I started final assembly of the vertical stabilizer. The parts were all primed yesterday so I start assembling the rear spar. As directed in the instructions, I put tape over the holes that will be riveted later to the inner skeleton.

The Isham tool kit is paying off. So far I have been able to set every rivet I needed to set without doing anything exotic.

Here is the front side showing the flush rivets on the lower end.

Next I riveted the three ribs to the front spar as directed. I could squeeze most, but I had to buck three with the double offset cupped set.

Wrapping Up the Horizontal Stabilizer – 6.5 hrs

I was off work today because the contractor was installing our kitchen cabinets and I need to be here to make sure everything was as it was supposed to be. I got started working on the horizontal stabilizer early and the contractor showed up with the cabinets about 9:30 AM. I squeezed the 220 rivets around the perimeter of the skins between checking in with the contractor. Once I had the pneumatic squeezer dialed in with the adjustable set I was getting very consistent nice quality rivets. I had about a dozen that sat slightly high in the countersink so I drilled those out and reset them. Fortunately I am getting good at drilling out rivets and was able to do them without enlarging the holes.

Then I put in the four blind pop rivets from the rear spar into the HS-708 ribs and set the four rivets between the HS-603PP rear spar and the HS-706 ribs. With that done I removed the blue film from the exterior of the skins because Vans recommends not keeping it on long term since it can get hard to remove over time.

Here she is –

That deserves another shot from the other side. The mirror-like skin looks gorgeous!

Here is the center section which eventually will mate to the aft fuselage.

If you look closely you will see 10 missing rivets. That’s not an error. The fairing between the HS and the rudder will install at those locations some day in the future.

At last the horizontal stabilizer is done, or at least I thought it was for a moment. That is when I saw two clecos sticking out of one end from the HS-708 rib. I forgot to put in two AN470D4-4 rivets into the front spar. Drat! The rear spar blocks access to buck those now so I had to use two blind rivets instead. Fortunately the loads are very low there at the tip of the HS so strength won’t be an issue and the fiberglass tips will eventually cover them, but it still bugs me. Again the lesson is that when you break the normal assembly order you run a greater risk of missing a step.

Nearing the Finish on the HS – 1.5 hrs

The finish line is near on the horizontal stabilizer. After priming the VS parts, I started to cleco on the rear spar on the horizontal stabilizer in preparation for final riveting on the perimeter. Then realizing that this was my last chance to check the inside cross rivets so I put on my quality inspector hat and rechecked every rivet. Out of about 120 rivets I found about 8 that were right at the low end of the spec range on diameter on the shop head (.122 dia min) so Denise and I gave those a few more taps with the rivet gun and bucking bar to put them closer to the .135 diameter nominal  for a 3/32 rivet.

Then I made sure the inside of the HS was clean and I cleco’d on the rear spar. Tomorrow I can start riveting the perimeter. And that will complete the horizontal stabilizer (except the tips which get added later).

Priming Vertical Stabilizer Parts – 3 hr

The weather was fantastic today. Clear sky, low humidity, and 70+ degrees. Not bad for mid February. I wanted to take advantage of the weather to get the vertical stabilizer parts.

I scrubbed all the ribs, spars and the stiffener with scotchbrite and Simple Green and rinsed them well. Then I dried the parts and laid them out on newspaper in the sun to bake off any residual water.

I used the Duplicolor primer again except on one internal rib where I tried a can of Rustoleum self etching primer I found at Auto Zone. My impression was it looks a lot like the Duplicolor but goes on much thicker than the Duplicolor which I don’t think is good. It may be the nozzle.

For the skin I followed the same procedure I used on the horizontal stabilizer. I removed the blue film in strips along the rivet lines.   Then I buffed the Alclad coating with scotchbrite and wiped the surfaces down with MEK. Then I sprayed NAPA 7220 self etching primer along the rivet lines. After about an hour of dry time I removed the rest of the blue film on the inside surface. Here is a picture of the vertical stabilizer parts all primed up.