aargh - Quickbuild wing bottom skin fit

[aerhed]

If you use Dan's "contortion" and find you still have a few that don't fit you might consider a few 1097 rivets for the last extremely stubborn ones (as long as dimples aren't misaligned too badly.

[dhall_polo]

Originally Posted by mototopo

Drilling out ALL the rivets in the skin will result in a LOT of enlarged holes.... I don't think it's the way to go.

Let me know what Van's says.

With a little practice, you can avoid enlarging the holes when you remove a rivet. A relative of mine worked for Lockheed, and he taught me a nice trick. Drill into the rivet head just enough that a little flick or twist of the drill bit will shear the rivet head off. Make sure you've stopped drilling when you do the little flick action. This works for either c/s or universal rivet heat). Once this is done, it's easier to accurately drill the remaining rivet shank out.

Don

[Wayne Gillispie]

That is the way mine were on one wing. I installed clecos in every hole in main spar and it pulled it around fine. Like Dan said a little twist in the wing is all it takes to throw you off 1/32" at the main spar. Eyeball down the main and rear spars and they are not perfectly straight. The skins are punched for perfectly straight spars. You just have to pull everything to where it is supposed to be.

[aerhed]

With a little practice, you can avoid enlarging the holes when you remove a rivet. A relative of mine worked for Lockheed, and he taught me a nice trick. Drill into the rivet head just enough that a little flick or twist of the drill bit will shear the rivet head off. Make sure you've stopped drilling when you do the little flick action. This works for either c/s or universal rivet heat). Once this is done, it's easier to accurately drill the remaining rivet shank out.

That's almost what I was taught in school, except use the butt end of the same size bit and just drill through the head stopping short of the skin. Use the butt of the bit to pry the head & it pops right off, then you can see the shank and really drill the center. The mfg head actually smears sideways a little when bucked making it off-center with the shank. That's why sometimes when you drill one & swear you're centered on the head but it misses the center of the shank. It's more pronounced with universal heads. The dimple helps keep the head aligned with the shank. Also, it helps to grind the butt of the bit flat & square, grabs better so you don't have to drill as deep. You can get away with bigger holes when squeezing, a big hole while bucking almost guarantees a tipped/smeared shop head.