The International Cessna^® 170 Association

Over the years my wing root fairing screws have been stripped out by mechanics that have been a bit over zealous with a screw gun. Is it possible to repair the oversized holes in the bottom of the wing at the root, by securing a #8 tinnerman nut, on the inside lip of the wing, with some type of adhesive and then utilizing flat head #8 sheet metal screws through a WA-8 finishing washer? Is it possible to do this without removing the wings?

I've also thought of using riv-nuts. But they are not as forgiving as sheet metal screws when it comes to installing the fairing strip after every annual.

There aren’t already Tinnermans in there? My ‘54 B has them, but they’re only accessible if you take out the fuel tanks.

Dave,
Thank you for the photo. That is what I was afraid of. Inaccessible tinnerman nuts. Looks like I will have to remove the tanks.

rollcloud wrote:Dave,
Thank you for the photo. That is what I was afraid of. Inaccessible tinnerman nuts. Looks like I will have to remove the tanks.

Yep, did mine a few years ago, hardest part is removing all the screws in the tank cover. Sometimes have to use a Dremel tool to cut a slot in the Phillips head screws and use a big flat blade screwdriver to remove them, (Mainly for the machine screws that go into the fasteners on the spar flange).

Before you take drastic measures to remove those tank screws, try soaking each screw overnight with Hoppe's #9 gun cleaning solvent. A drop on each screw is plenty. A light tap with a small hammer helps as well. I have had very good luck with Hoppe's breaking loose corroded fasteners. It won't hurt aluminum.

We had the same problem on our '56 172. I was able to slide a normal Tinnerman between the lower wing skin and rib. You will need to grind off the little upward tang on the inside end of the Tinnerman to allow it to fit. It is not a perfect solution but it works.

I don’t have a pic but saw a solution to this using https://www.aircraftspruce.com/catalog/ ... -00364.php

GAHorn wrote:I don’t have a pic but saw a solution to this using https://www.aircraftspruce.com/catalog/ ... -00364.php

That is the style of Tinnerman that I slid between the skins. It worked great I just had to grind it a little bit to remove the tang.