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Rudder Trailing Edge

skelrad

Well Known Member
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I used the VHB tape that is now recommended in the manual for trailing edges. I don't love how it turned out. I have no idea what I did wrong. The trailing edge is pretty straight, but the tape obviously did not hold the skin to the wedge, so the puckering of the skin is pretty bad. Everything looked great when it was clecoed to the aluminum angle, but as I riveted, it all went downhill. I back riveted just enough to set the rivets, then turned it over so the shop head was on the back rivet plate and set them the rest of the way.

I'm not sure if I leave it since overall it's straight, or if I need to try to remedy it somehow. A mechanic I know just said "looks like most Cessnas - that's what bondo is for." Do I leave it? I'm just not sure what to do different next time.
 

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Just checked my rudder, looks the same. Never noticed that before. Aircraft flies straight and true.

I think if your trailing edge is straight, you're good to go.
 
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I used the VHB tape that is now recommended in the manual for trailing edges. Boy, I'm not a happy camper with how it turned out. I have no idea what I did wrong. The trailing edge is pretty straight, but the tape obviously did not hold the skin to the wedge, so the puckering of the skin is terrible. Everything looked great when it was clecoed to the aluminum angle, but as I riveted, it all went downhill. I back riveted just enough to set the rivets, then turned it over so the shop head was on the back rivet plate and set them the rest of the way.

I'm not sure if I leave it since overall it's straight, or if I need to try to remedy it somehow. A mechanic I know just said "looks like most Cessnas - that's what bondo is for." Do I leave it? I'm just not sure what to do different next time.

The counter sunk holes in the AEX (VA-140) material weren't deep enough to accommodate the dimples AND the VHB tape.

This might be a camera thing but your skin edges don't look like they have the correct de-burred profile (see manual chapter 5, 5.2 Edge Finishing, Figure 1.)

Mix up some epoxy with milled fibers (glass fibers) and slather in the TE gaps. Sand away the excess.
 
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I ruined my first trailing edge wedge trying to get it countersunk deep enough to accommodate the tape and the dimples.

Ordered another one, abandoned the tape, went with pro seal and still got a result that looks just like yours. I don't think that the wedge and the skins are at the same angle and thats just way it is.
 
Did you apply a small break to the skin at the trailing edge where it contacts the extruded piece? (before dimpling)
 
Did you apply a small break to the skin at the trailing edge where it contacts the extruded piece? (before dimpling)

I didn't. I remember reading about that in the build intro, but mentally connected it with actual overlapping skins and didn't think about it for the rudder until I had already dimpled and it was too late.

Based on replies so far, sounds like I should leave it as is or beautify it later with a little cover up body work. There are a lot of little waves in the edge because of the pillowing, but there's no real bow or curve in the edge. I think it's more of an eye sore for me than a functional problem.

The wedge was countersunk the typical. 007" below flush on both sides. I was hesitant to go much further than that. I think I can deal with this trailing edge, but just trying to figure out what to do different for the next attempt, since I'll be ready to tackle the elevator trailing edges in just a few days.
 
Countersink

Did you countersink the wedge with 120 degree CS?
This is especially important on the TE, as the dimples will not nest in a 100 degree CS as well. The tape also accentuates this if the CS is 100 vs 120.
 
I didn't. I remember reading about that in the build intro, but mentally connected it with actual overlapping skins and didn't think about it for the rudder until I had already dimpled and it was too late.

I’ve done it on the -14 in all places where the edge of a skin needs to sit flat. So the rudder trailing edge, elevators, flaps, ailerons. Also anywhere skins overlapped.

On the -14 it is called for in the rudder plans.

I also tend to go a bit deeper than 0.007” on the trailing edge. For me, once both sides are countersunk, the hole is **almost** knife edged. You can see that I mean here: https://tasrv14.blogspot.com/2021/07/21-05-06-flap-skin-trailing-edge.html?m=1
 

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I had a few places I wasn't happy with on a flap on the trailing edge, and used a plastic syringe filled with ProSeal. I positioned it such that I could almost inject the ProSeal into the gap, then wiped it flush between the little bit of trailing edge and skin difference.

I figured the slight flexibility of the ProSeal might hold up better than a resin solution, in this area that would likely see much vibration down the road.

Lance
 
How much Proseal for rudder?

I'm building an RV-10. How much pro seal should I buy for a rudder (or the elevators)? Options at Aircraft Spruce are 2oz cartridge, 3.5oz cartridge, and 16oz can.

Thanks!
 
This is not unusual. I suggest filling any gaps with JB Weld, let it set, use a fine file for good cosmetics, and after primer and paint, you will not see it!

DAR Gary
 
Good day. Anyone know the reco'ed tape width for the 3m F9460PC edge tape? I have some but it's .375 inch and looks too narrow. the wedge is 1/2 inch....so I guess that would be the reco. Thanks in advance.
 
3M F9460PC VHB ADHESIVE TRANSFER TAPE - 1/2" X 60 YDS

I bought it at Uline. I think it was approx $35. It did an ok job but from what understand pro seal may give better results. I think my trailing edge came out great, no wait time like with pro seal, and no mess. As I understand it, and someone please correct me if I am wrong, once the trailing edge is riveted it doesn’t matter which you use. The rivets are the only holding force at that point. Assuming this is correct, I will continue to use the tape. Waiting to hear from the experts on this one…
 
Same on my -10. I used tape for the elevator trailing edges, and I wish I would have stuck with proseal. I haven't explored injecting something in the gaps, but will likely complete at some point....
 
Why

Why do we need to tape or pro seal at all? Has anyone just riveted it dry? I get the holding things straight but looking it over- I don’t see the issue.

I’m at this step now an afraid to start hearing all the outcomes.
 
riveting “dry”

my TE bowed when I riveted it dry- without proseal or 3M tape. it was completely straight when match drilled and clecoed on a plywood board. apparently it can move some during the riveting stresses. hard to fix once bowed.
Cal
 
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