Oil canning in top wing skin

Moved from the RV14 section:

I?ve just put the left wing on the workbench preparing to rivet the top skins. After clecoing the skins, one panel as depicted in green has minor oil canning. I clecoed the skins following the Vans recommended pattern ( center point of the middle rib, longitudinally up and down as I moved out laterally toward the root and tip)
After finishing the clecoing, one panel has minor oil canning,( green highlight below) none of the other panels have oil canning nor does the same point on the clecoed right wing....
I?ve read where it may be a rib flange that isn?t sitting perfectly at 90 deg. to the spar, but will check it early next week. Are there other things to check and associated remedies?
The clecoes are in place, skipping every other hole and the j-channel isn?t in place. Maybe clecoing every hole around the effected area replicating the rivets might be a realistic indicator.....

The spar is ? centered bubble? on the bench and the twist has been checked with a plumbbob and it?s negligible.


Thanks
Jt

Just about every RV I've seen has some small oil canning here and there ... If it's minor like you've said, I wouldn't put too much effort into trying to redo/fix it ... just build on

The wing skin takes 100% shear loads (not wing bending)... Buckling in one bay does not affect the shear strength. Aesthetics aside, painted you will not see it unless you look for it at specific angles. This often seen in fuselage and wing spar webs in aircraft. In fuselage of large aircraft the diagonal buckles goes away when pressurized. To make the skin not do this would make it heavier; the skin thickness is sized sufficiently for strength with bucking... The skin takes load even buckled in diagonal tension.

Cleco the j channel into place. I had similar issue on my build. I ended up r and r-ing the j channel and it fixed the problem. Not all j channel are exactly the same. My oil canning was quite substantial.
Best way to eleviate oil canning is don?t check for it!

Best way to eleviate oil canning is don?t check for it!

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Yup

I have one spot on the side of my emp when the temp fluctuates, like when I first pull it out in the sun, you'll hear a slight "boink" when the skin "oil cans" ... nobody would ever know otherwise ...

mc607 said:

Best way to eleviate oil canning is don?t check for it!

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Not sure if I agree with that.

JT,
Considering that you have only clecoed the skin, that might be one reason as rivets will pull the skin much tighter in place. That area to my knowledge is not the typical place in the 14 to have oil canning issue, so it is worth double checking everything to see why. The four RV14 in my area that I have looked, don't have that.
The most common area for oil canning in the 14, I believe, is the side skins and bottom skin between the luggage area and the tail portion.

There is a remedy for that if it is of rather pronounced situation.

The most common area for oil canning in the 14, I believe, is the side skins and bottom skin between the luggage area and the tail portion.

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This is where mine is and only one side, minor.

If the skin doesn't vibrate in flight, I'd consider ignoring it.

One issue with "fitting" skins with cleecos, is that they aren't accurate positioners.

I was taught by guys who learned their trade in the WW-II aircraft factories, Lockheed, Northrup and McDonnell, to use 1/8" holes at the corners or other key spots and insert a rivet for a position locator. The cleecos were used only to hold the skin onto the substructure.

Your oil canning may be a product of that limitation regarding cleecos.

Onward and upward

Marc