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Wing skin alignment issue

amaris

Well Known Member
I did a bit of reading up on this issue before asking, so I need to ask again for possible solutions.

I'm buttoning up my outboard bottom skin and not able to get the top row of rivets that attach to the main spar to line up. They're about 1/64" off, so the rivet will only go in at 45 degrees if I'm able to get it in.

Everything lined up fine when did the initial cleco up. Though I have found that clecos don't alway make a perfect alignment. Sometimes the cleco goes in just fine but a rivet will be misaligned.

I started riveting inboard and working my way from middle of skin to forward and aft as others have suggested. Many have reported as you rivet in each direction the skin will work into place. That's not happening for me.

I can't do any more riveting as I need to get to do the first few main spar rivets before I can continue working outboard.

I've also tried moving from the bench to the stand and same thing. I also tried giving a little pressure on the rear spar with the jack to see if some pressure would help.

Any further suggestions? And what if no other tricks work?
 
I had a similar issue with my 8's bottom skins, I employed deferential thermal expansion to stretch the skin just enough by the close application of heat with several 500 watt halogen work lights.
 
Trying to force the skin into alignment at this point may create a ripple effect in the bottom skin as it stretches. I hope you just started & don't have to redo too much.
What I'd do is drill out the rib rivets, leave a few of the rear spar rivets in place in the bottom corner. Re-align the skin to the main spar with clecos & Awls. Install at few rivets in the inboard front spar corner, this should lock the skin into alignment. Now use the Awl to align the first inboard rib holes & rivet them down in what ever pattern you prefer. Follow by doing front & rear spar holes to next rib & continue this pattern outboard.
Good building!
 
Thank you both. I have heard about heating the skins in the sun or with a heater. I will have to give that a try to see if it helps.

Ralph, I'm 3 ribs in. So while not that far, that's sure a lot of work to remove and could lead to some elongated holes. I'm pretty good at drilling out rivets, but the odds are against me with that many. Though it seems no matter which way I start, I'm still going to be slightly off and will be in the same situation.
 
Would be harder to align, but you could try drilling just the inboard edge rib rivets (ties the two bottom skins together & is the cause of the misalignment), than use clekos to work the main spar holes in line, than rivet the spar in that first bay to lock the alignment.

Get practiced drilling rivets, it's a skill worth being good at when building these planes.
 
I kicked this up to Vans to see any suggestions. Sterling said if they find an occasional hole that is slightly off, they'll use the awl to pull it in. But in this case, he said try to use the halogen lamp approach as they've had this work moving the skins when up to 1/16" off.

I only have one halogen lamp these days since I've upgraded to LED, so I'll use my portable heater instead.

I had a similar issue with my 8's bottom skins, I employed deferential thermal expansion to stretch the skin just enough by the close application of heat with several 500 watt halogen work lights.
 
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