The "Foul Fitting Fuel Filler Fix"


After installing my wing tanks, to my surprise, I noticed there was a gap between the wing and the filler hole on the fuel tank. In my desire to press-on, I put some cork around the hole and riveted down the nose-skin on my first wing.
I pondered this for quite a long time while building the second wing and after many ideas on paper, I think I came up with a real winner.
The criteria was to design a flush-fitting fuel door that I could install in a completed wing as well as the not-yet-completed wing. It had to be light weight and slinder to slide under the completed wingskin.


This is the problem that faced me when I installed the tank. The material between the wingskin and the tank is cork. Cork is not necessary for this modification so I removed it.





See the resulting final product below:




Here's a view of my lovely assistant peeking through the opening:




The parts before installation look like this:




The back of the .032-inch thick "Paddle" looks like this (with a block of .125" aluminum flush-riveted:




Here's a drawing of the filler door:




You can install this on an existing, finished wing, or before completion. If the wing is not closed up, just clamp the backing plate to the nose skin and back drill for exact location of the rivet holes. If the wing is already closed up, use plexiglass to locate the filler hole and the rivet holes. The entire assembly can be slipped under the nose skin by removing a minimal number of rivets. The pivot point for the paddle is an existing rivet. For a looser fit, drill the hole in the paddle a little larger. This would also make an excellent inspection door in the right application.

Happy building,

Scott Laughlin