Made a bunch of rudder stiffeners tonight:
The balloons attached to the second fuel tank have been inflated for about a week now. That's more than ample proof that the tank is not leaking, I think. Hooray for proseal!
Mary came out and helped me wrestle the wing back into the wing stand. Barring something unforseen, the wings should be staying in the rack for quite a while.
Look at this. This is the trailing edge of the rudder. It's so wavy it hurts to look at it.
I know I said I was happy with it, but now that I've really stared at other RV's and seen how it's supposed to look, I hate it.
So, I'm going to re-skin the rudder. I started tonight by drilling out all the rivets holding the top rib in place.
Then I drilled out about 300 more rivets, until the skin was completely detached from the skeleton. The skeleton is in good shape – only a small handful of rivet holes got elongated, and they can be fixed with oops rivets.
So, now all I need to do is make new stiffeners, rivet them to a new pair of skins, and put the new skins on the old skeleton. Luckily I decided I was probably going to do this a few months back, and I have all the materials I need sitting around.
No progress on the RV in a while, as I've been busy at work. I also took some days off to go on a 3000-nm trip with a friend in his Super Decathlon. Awesome.
Getting back to the project, tonight I did some cleaning in the garage/workshop, and rolled and riveted the leading edge of the rudder. It turned out acceptably well. Sorry, no pictures – still having intermittent trouble with the machine that I use to grab photos from the camera.
Riveting the trailing edge of the rudder is one of those tasks that I've been dreading – not just because of all the horror stories, but also because you can tell just by looking at the plans that this part sucks. The goal is to get the trailing edge of the rudder to a) come out straight, and b) have as little waviness to it as possible.
The manual lays out a procedure for doing this that involves the back rivet set – other builders have had success with different methods involving the use of the pneumatic squeezer (1, 2). I started out by grinding one of my flat rivet sets to an angle that matches the trailing edge of the rudder:
Then I clamped angle stock to both sides of the trailing edge, just forward of the rivet line. Using two flat sets in the squeezer, I worked from the center out, setting each rivet about halfway.
You can't see it here, but I put each rivet in from the opposite direction as its neighbor. I figured that would help balance out any tendency for the riveting process to want to bow the trailing edge in one direction or the other.
At this point, everything was going great. Then I switched to the special angled squeezer set with the intention of finishing the process of squashing the shop heads of the rivets until they were flush with the skin. It didn't turn out as nice as I'd hoped – not only did the shop heads not get set all the way flush, but the act of clamping down on the trailing edge with the squeezer caused some "pillowing" of the skin between each rivet. After finishing this process, looking the rudder over, and saying some bad words, I got out my back rivet plate and mushroom set, and went over all the rivets again until they were all perfectly flush.
You can't see the details very well in this photo, but here it is:
It turned out to be almost perfectly straight overall (only about a tenth of an inch deviation along its entire length) but it does have some pillowing and a slight amount of waviness between successive rivets. I think it will look okay after it's painted, though, and at least it's aerodynamically acceptable. I now know that setting the rivets partway with the squeezer and then finishing with the rivet gun is probably the best way to go. Oh well, the rudder trailing edge on my next airplane will be perfect. Or, I may re-skin this rudder some day if I have some downtime. I am glad that I put in each rivet in alternating directions, and I'm fairly pleased with the way the shop heads of the double flush rivets turned out. When it's painted you might not even be able to tell which side is the manufactured head and which is the shop head.
I think it's safe to say that no manganese dioxide-cured polysulfide sealant has destroyed more marriages than Proseal. Luckily Mary is still speaking to me after I convinced her to help me Proseal the rudder trailing edge tonight. What a mess. I'd forgotten how much I hate that stuff – an enmity I developed while working on the fuel tanks of my previous RV. Having an extra pair of hands around was a huge help, though. Mary is awesome and now I feel compelled to buy her something shiny.
This sucker will cure for a week before I take out the clecoes and put in the rivets. Note that a 48-count box of wooden clothespins from Dillon's yields exactly enough to help clamp down the trailing edge of an RV-7/9 rudder, plus one extra to put on your nose while you mix up the goop. Coincidence?