Elevator oil canning

What next!
The left elevator that came with my kit was pre-made by Vans but had so much twist in it, it was unusable. The counterweight hung more than halfway below the stab and you could see the bow in the trailing edge. I tried rebuilding it but the skeleton even had the twist.

The new elevator I built, I thought turned out perfect but after almost all the rivets were in, there is a noticeable oil canning back and forth between a set of stiffeners on the top. See "X"s on the picture

http://pages.suddenlink.net/tismuoi9/Lelevator.jpg

You have to look close to see any distortion but the two areas obviously "pop" back and forth.

What do I do now?
1) Build and fly the plane as is and replace the elevator when the fatigue cracks occur(as they will probably sooner than later).
2) Do it over for a third time
3) Reskin both elevators with .020
4) Find some way to stabilize the skin
5) Sell the kit and take up stamp-collecting

Dave A.
RV-6A QB

Dave:

My elevator has some oilcanning in that same area. I built on, and have not noticed any ill effects, either in control of the aircraft or any cracks in the skin.

I guess if it really bothers you, building another one is always an option. I think the reason I got some oilcanning was because my backriveting plate was just a fraction lower than the surface supporting the skin when I riveted. This resulted in a slight stretching of the elevator skin. Take that for what it is worth should you decide to rebuild.

One thing to also consider is that once you curl your leading edge, enough tension may be placed on the skin to prevent it from oilcanning.


Regards

Oilcanning

Jeff,
Good point. I feel better.
I'm keeping my fingers crossed.
I believe mine occurred after firing the honkin CS4-4 rivets on the trim tab spar. All the main spar holes were prepunched and I made a pretty good jig so I don't think I pushed or pulled anything on riveting but who knows.

Dave A.

The link above isn't working. Mind putting the picture back in place?

elevator canning

Sorry, my bad.
I either blew the handoff to the webserver or had brainlock
The link should work now.

Dave A.

stiffeners

Followup on my question about "oil canning" on elevator skin.

Discussed the situation with some knowledgeable people at Vans. The elevator canning can produce some undesirable and hard to trace flight characteristics and they advised fixing or rebuilding.

Their suggested fix which apparently they have done before involved using very light (.016) stiffeners placed diagonally and held it place with a thin film of proseal.

I reriveted the elevator with the stiffeners in place and the oilcanning is gone. I won't know if there is any issues left until the plane is flown but the elevator appears to still be true and solid.




Dave A.
6A

Proseal's good stuff!

You can also bond your fresh air inlets in place when the time comes...ours have 4 years/500 hours.

Regards,

Stiffener installation

My 9A wings had oil canning on the top skins at bays 7 and 8, aft of the spar, of corse. This appeared on both wings, and after much thought, and a call to Vans, (the only one I can remember making) I riveted spanwise stiffeners at the center of the bays at all 4 locations.
Worked like a charm...but, bonding them would have been just as effective.
BTW...Pierre is right about bonding in the NACA vents on the fuse. I riveted mine in, and spent mucho time hiding the rivets after they were in. They look great, but Man....I sure wished I had glued them to start with!!

Regards,
Chris