Wing root fairing attachment

I have a friend that is finishing up his RV6A and he forgot to install the nutplates on the top skin for the wing root fairings before installing the wings. As you know this is no small task to remove the wings on a 6 so he is looking for ideas on how to get this done.

Also, as an option, he has a set of Fairings Etc. fairings that he could use if this will be easier.

Anyone have any words of wisdom to share with him....

Self tapping screws

Brian,
My factory-built Air Tractor 502 has self tapping screws on the wings and tail fairings (Since 1989). If your buddy is careful to not overtighten them, the aluminum fairings can be dimpled and held with these screws and a little Loctite....not sure that it's even needed.
Regards,
Pierre

blind rivets?

Is there room to install the nutplates with blind rivets? My buddy Kye has blind rivets on those nutplates on his beautiful -6A. Maybe some small fingers would help, too?

Nutplates

Brian, this is a simple problem here..I have done the same thing on my -4. Simply drill them up with the nutplate jig as normal,however, instead of dimpling the skin it will be countersunk for the 3/32 rivits. Now you use a trick we call "fishing" in the aviation industry...you feed a piece of safety wire down through the screw hole and let it come out the bottom or curve it around to the top of the gap between wing and fuselage, then slip a nutplate on it, and twist a little ball to catch it.Now, pull it through up against the skin,cleco, and pop rivet in place. Problem solved easily ! Dont worry about knife edging the skin,as there is not enough load to creat any problems.
Good luck,
Bill E.
RV-4 paint prep

I am sure he is resolved to using countersunk blind rivets to rivet the nutplates in but he is more concerned with how to dimple the screw holes. The 6 has very little room between the top skin and the fuse. Too little to get a yoke in there.

I mentioned the screw dimple dies that Avery sells that use a bolt to pull them together. Also, I think you could just countersink the screw hole like we do on the spars for the fuel tanks but I think he is worried about cracks if he does that. I guess one could just drill the screw hole oversize instead of countersinking in order to prevent the dreaded knife edge.

He is watching this thread I assume so any comments or suggestions are appreciated. Thanks for all the responses!

I used half the number of screws as shown in the plans, or twice the spacing. There is a very small amount of pucker but it still looks better than most with twice that many screws. You do not necessarily need #8 screws.
You also do not need to use flat head screws. Not sure how it would look with truss heads, but I would suspect it would not look bad at all. I also like the idea of the self tapping screws. The fairing wraps around the leading edge and there is very little force trying to "lift" the fairing off. Truss head self tapping screws would make the job really easy if you can live with the look.
Now, that said, it would take less than a day to pull the wings and do the job right. Nobody likes to back up, but it is really easy to spend more time worrying about a problem than it is to fix it.
All will be forgotten when the airplane jumps into the air.

Pop rivet dimple dies

I think Avery's sells a set of pop rivet dimple dies that you should be able to dimple the holes with. I know he has 3/32 pop rivet dimple dies because I have some.

My Experience

My experience was that I had to put the wings on to fit the fairings, and then take them off to do the dimpling and nutplates. And yes they are a pain to get on and off.

Nucleus

Hmm...

The -6 must be different than the -7. On the -7 you have three pieces on top (rib flange, wing walk doubler, top skin) and on the bottom you have two (rib flange, bottom skin). I've never been able to get a good dimple by dimpling two pieces simultaneously -- much less three. The -7 plans have you countersink these holes on top and bottom and install K1000-08 (standard #8 nutplates) on the top and K1100-08 (dimpled #8 nutplates) on the bottom.

You need the dimpled ones on the bottom because the screws may penetrate just enough through the skins to require the dimples.

The tank is to be dimpled but you should be able to reach these with a squeezer. If all else fails, just put pop-rivets in there as suggested. They'll get covered and no one will see them.