Trailing edges: A somewhat expensive "oh well"

It's a setback, but probably more so a learning experience to really take your time. I've decided that, eventually, I will rebuild my rudder and right elevator. The trailing edges on both, frankly, look like **** compared to the pictures of other builders'.

The rudder's trailing edge is straight. But the skins, in hindsight, don't lay to the wedge very well. You can separately see, and feel, the right and left skin edges and the AEX wedge. Plus the leading edge had to be rolled twice, so it's not great in its own right. This was before I learned of the gem of an edge rolling tool. And for whatever reason, as I did with the right elevator, I wasn't using an angle to hold everything together, or proseal (just some standard RTV sealant I picked up at Autozone).

When countersinking the right elevator's AEX, I determine I way over-countersinked the one side. Start to countersink the other side, and between the pilot wobbling and such, the holes themselves get opened up to more than #30(!!!). Oops rivets wouldn't even fill these. Start to rivet it onto the skin, and needless to say things just don't lay flush like they should. Oh, they were fine during fitting and drilling. But after drilling out 2-3x, the skin holes are pretty much at edge tolerance, and beyond my personal "looks like ****" threshold.

Lessons learned: 1) Use the rigid angle when drilling the trailing edges, no matter what. I think it's both to give the straightness to the edge, and also for the clecos something more to bite in, for more compressive hold. 2) Use more clamps! Clecos aren't enough on this one, I don't think. 3) Use proseal. Or at least put a heck of a lot more sealant on, so it's actually really sticks. I think I was being a bit stingy, just because it was so **** hard to squeeze the tube (that stuff's thick!) . 4) Don't over-countersink the AEX, even if you're trying to follow that "countersink a little bit more than the rivet head, to give the skin dimple somewhere to sit" rule. 5) There's probably enough to make lessons #5 - 10 on this, but it's lunch time.

Needless to say, it was a comparatively bad weekend... Best part is, I'm not really *that* bummed. Finishing work on the left elevator, which oddly I feel better about now, my wing kit's inventoried, other accessories are on their way, etc. I've got more than enough to keep busy. And in the grand scheme, the couple hundred bucks for a new rudder and right elevator is not that big a deal. A few hours' worth of rental in a Cirrus lost.

Okay, lesson learned / vent session over. Building onward...

P.S. For those who edge roll the skin trailing edge, I've read that you just edge roll the very bottom edge, right below the rivet holes for the AEX. Others say above the holes (so the rivet hole is on the bent edge). Which should I use, for practicing (and probably eventual usage on the left elevator)?

Give it a few days. I have found, the more time between me and an "oops," the better my perspective and outlook tend to be. It would be worth it to have another builder look at your work before you drop $$$ for new parts.

I've had several of those moments in my build and I made the decision early on to keep of list of them to re-evaluate as the build progressed before first flight, to see if my perspective about them changed or I learned a new technique for dealing with it.

More than half of those things have evaporated as "insignificant" and I'm not flying yet. Keep a list, drop the worry.

Ya, I'm fine. Like I said, I've already put it off to the side and am moving on. Between that, and trading emails with Rockwood. He had an idea he saw on another plane that I might look at later.

The rudder is fine - already had my TC look at it a few weeks back when I finished it. But the relative mutilation I did to the right elevator's AEX yesterday just had me in a huff. And like I told Rockwood in my email, a few hundred bucks is a shrug in the scope of this project. So the idea of restart vs salvage is on equal pain footing. I'll probably just end up ordering a new AEX down the road. There are only a handful of holes on the skin trailing edge row that are rather large. Who knows, maybe the whole right elevator trailing edge will be filled with all Oops Rivets.

Anyway, mutter, grumble, groan, moving on...

I've got a few spots on my rudder that I'm not happy with, and I'll almost certainly end up rebuilding my elevator trim tab - but they are cosmetic and will make it through Phase I. I'll fix all that stuff just before I take it in for paint, after Phase I is complete.

AEX Countersinking

At least now you have a piece of AEX Wedge to practice on It seems part of the learning curve is to jack-up at least one element of the empennage. For me it was the horizontal stabilizer... went back and rebuilt it while waiting for wings. Oh yeah, did about four trim tabs too...

Proseal - I used proseal for elevators and the rudders, additionally these were cleco'd directly to a 2" x 2" x 1/8" aluminum angle and weighted down to the table before drilling and while the proseal cured. (1/16" bead down both sides of AEX)

For your future ref: I just finished the Ailerons and DID NOT use pro-seal on the trailing edges; they turned out perfect, just following the instructions. The key here was a flat table and weights - on my builders log link below you can see the concrete weights on my ailerons.

"through phase 1"

I'm like Greg, have a few things I wished I did better, but cosmetic. . . things I figure I'll replace at first annual after phase 1.

Somehow, I don't think it's going to happen. One of two things will happen (or maybe both?) : I will be channeling my inner Vlad and flying the paint off the thing, as well as planning the RV-8.

Advice is the same as others: get yourself a little emotional distance, go to the ariport and see how sloppily (if that's a word) production aircraft are built, pick a good painter (the best pseudo-sin forgiver you can have!) and recognize that from the left seat, none of those little doinks matter.

sbalmos said:

....For those who edge roll the skin trailing edge, I've read that you just edge roll the very bottom edge, right below the rivet holes for the AEX. Others say above the holes (so the rivet hole is on the bent edge). Which should I use, for practicing (and probably eventual usage on the left elevator)?

Click to expand...

The edges on my Cessna 180 are slightly bent just in from the edge. The bend is between the edge and the line of rivets, much closer to the edge than to the rivets.

Dave