Today was trim tab day. Funny how a part so small can take so long to do. I'd already drilled, primed and dimpled the skin and spar, so the next step was to bend both ends of the skin to make 90 degree tabs for the ends. I sure wish Van's had made these bends! There were 4 bends to make. By the time I got to the 4th one I had it 50% figured out, meaning the first three were kind of a mess. On the first one the form slipped little by little as I hammered the bend in place. That made the bend about 1/8" beyond where I really wanted it to be. Part of me wanted to order a time skin and try again, but it's just a trim tab, and I know it's really not a huge deal. By the end, I'd learned to clamp things down as tight as possible (which unfortunately led to a few creases in the skin that I'll have to put some lipstick on down the road) and also back the bottom form up with a 2x4 that was screwed to the bench so it wouldn't migrate as I hammered on it.
I feel like this blog is kind of like confession - look closely and see if you can spot my mistake in the picture below.
Somehow, when prepping the skins to receive the control horns, I missed dimpling a hole. The vast majority of the time that's not a big deal at all since you can just dimple when you find the mistake. In this case, I had already riveted on the control horns by the time I saw it. My only options were to drill out all of the rivets in the control horns or simply try to dimple both layers of aluminum at the same time and accept the less than perfect outcome. I opted for the latter. The result was actually fairly good, so moving on.
The hinge that links the trim tab to the elevator was next. This is a great example of how the instructions have changed over the course of the build. Whereas initially they walked step by step through things, that's no longer the case. Now, it says things like "cleco, drill, deburr, and dimple the skin and spar and hinge." That leaves a lot to figure out just by staring at the plans and trying to figure out where to make cuts, what order to stack parts in, which side is "up" on the hinge, etc. I think mostly it's a lesson in the fact that the minutia really doesn't matter in most cases.
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I didn't get any pictures of the next part because of the mess - time to Proseal the foam ribs into the skins. People aren't lying. Proseal is incredibly sticky and messy! The only gotcha with this was the fact that my digital scale doesn't measure in small enough increments to do the 10:1 ratio. I only needed a very small amount to cover the foam ribs, so I had to eyeball the ratio to a certain extent. Time will tell if I got it close enough. A lot of head scratching and double checking later, I had the hinge cut, drilled, and riveted onto the trim tab spar. I put my wood forms over the foam/Prosealed ribs to squeeze it all together and will leave that in place for the next week while it cures. Following that, I'll need to match drill the other half of the hinge to the spar on the elevator, then this will all be done and it'll be time to mate the elevators to the horizontal stabilizer, and do the same with the vertical stabilizer and rudder (an initial fit anyway - the final fit isn't done until it's all attached to the fuselage).
It's hard to believe, but that means it's time to start the wings! I was ready to pack it in for the day but just couldn't help from at least taking a look at what I am up against. I pulled down the bag of wing hardware and organized it. A lot of the rivets could be consolidated with the leftover tail rivets of the same size, but there was a shockingly wide variety of new rivet sizes for the wings. I had no idea so many slight variations of blind rivets existed.
I unpacked the spar crate (1 of 2 wing crates) and pulled the spars out. I'm not sure what will be the most convenient orientation to work on these, but for now spun my workbench 90 degrees. Ultimately the spars will get mounted on a stand, but I'll probably leave them on the bench for the first few build steps. They are in good condition with the exception of one scratch in the right web that will need to be sanded/smoothed out. Since these are already alodined, I'll either just hit the scratch with primer or buy an alodine pen for the area I fix.
I stared at the plans for a solid 30 minutes to decipher the first sentence of the instructions. I think I've got it sorted out now - basically my first step is to install a ton of nutplates (looks like Van's uses the term nuplates vs platenuts) in the inboard spar flange. These will partially be how the fuel tank attaches to the spar. So that one sentence of instructions will take me a number of days - set up a way to hold the spars, countersink, prime the countersink, and rivet on the nutplates.
The next question I need to answer is whether I'm going to build one wing at a time or both simultaneously. I'd prefer to do both at the same time, but it depends on space. We'll see if I can figure out a way to get the wing jig in place for both wings and not run out of room.
