Replace leaking wing tank. Adding tank to wing with no tank. Need help.

[Emory Bored 61]

I've been considering using riv-nuts to hold the fairings on my biplane.  They are currently held on with screws and nylock nuts requiring two people to get the fairings off for annual.  Not great.  I decided though, perhaps without merit, that eventually the riv-nuts would loosen and spin in their holes.  The grip length after all is only .016 or .024.  I've decided to use those *two hole wing doodies that rivet to the skin.  I think that the epoxy idea is a good one in your application. 

 

* "Two hole wing doodies" = AN366F

[Luked 71]

This is a great thread. Thanks Bandit for showing us what you did.

I've got some personal experience with rivnuts since we've been using them in the products our business makes for about 12 years now. I'd suggest using the type that have the ribs (splines?) on the barrel like Knuckldragger posted. They grip better and help avoid spinning in the hole. I think the only kind you can get from spruce are the smooth kind. You can get the gripping kind from Mcmaster.

http://www.mcmaster.com/#standard-rivet-nuts/=10haaay

Nut plates are definitely better since there is no way they can spin, but they are a little more work, and in some cases can increase weight if there are very many of them.

Edit: can't get a direct link to the specific kind of rivnut to work, but just click on "Heavy Duty Rivet Nuts" from the link above.

Edited 31 Dec 2015 by Luked

[rdooley79 28]

So what do you guys think? 

Would you go with fabric and wood over the tank like has been done many times or would you use the thin aluminum skin attached with epoxied in rivnuts? 

 

I like the aluminum skin for so many practical reasons. Also with my wing paint design, I think the panel wouldn't be very visible if I match the pattern well. 

Should I go that route or fabric? 

[EDMO 1078]

One added comment about the rivnuts - I have used a lot of them in my plane - If you will put some medium threadlocker on the bolts - (NOT the kind that take heat to loosen the bolts), or use something like Loctite 545, a sealer for hydraulic fittings, then the bolts wont vibrate loose.

And another comment:  The steel rivnuts take a LOT of force to squeeze them - but you could insert them and use epoxy instead of squeezing them completely which might crush or break the wood ribcaps - or use aluminum rivnuts, which don't take as much force.

There are other types of inserts used in wood furniture - check out that drawer in the Lowes hardware department, or some other source, such as Grainger. MSC, or McMaster.

EDMO

Edited 31 Dec 2015 by EDMO

[Av8r3400 1177]

I used a dab of red lock tight on mine...

[Bandit 286]

Got it!  It all makes sense now, I think.

http://amzn.to/1YR7sOO

I just found them in Aircraft Spruce. Nutserts.

[EDMO 1078]

Got it!  It all makes sense now, I think.

http://amzn.to/1YR7sOO

I just found them in Aircraft Spruce. Nutserts.

Bandit,  The Nutserts which expand outward will crack wood, and are not the same as Rivnuts which compress lengthwise.  EDMO

[Bandit 286]

Got it!  It all makes sense now, I think.

http://amzn.to/1YR7sOO

I just found them in Aircraft Spruce. Nutserts.

Bandit,  The Nutserts which expand outward will crack wood, and are not the same as Rivnuts which compress lengthwise.  EDMO

Nutserts are what I used to secure the aluminum cover on my wing. You do have to be careful when crimping them though.

 

Edited 1 Jan 2016 by Bandit

[EDMO 1078]

Got it!  It all makes sense now, I think.

http://amzn.to/1YR7sOO

I just found them in Aircraft Spruce. Nutserts.

Bandit,  The Nutserts which expand outward will crack wood, and are not the same as Rivnuts which compress lengthwise.  EDMO

Nutserts are what I used to secure the aluminum cover on my wing. You do have to be careful when crimping them though.

 

I just wanted everyone else to know that there is a difference.  I mostly use Rivnuts unless I am working with 1/4" thick material.

EDMO