Stiffeners, Fuel Caps & Drains

Time: 5 Hours

I had a good breakfast with a couple of fellow builders and spent a few hours talking shop this morning. When I got home I decided to continue the momentum I had built up yesterday. I grabbed the other tank and setup all the supplies I would need for the task. With everything set I grabbed the ProSeal and made the measurements.

I did the same procedure as before, I buttered the flange of the stiffener and placed it over the rivets and set them with my back rivet set. I then loaded up a 2.5oz disposable Semco tube to hit all the shop heads of the rivets. Since I didn’t get photos of this the first time I decided to take a little time with these for some.

20140223-183935.jpg

Then I removed the electrical tape to reveal the clean lines.

I left the tanks sit for a couple hours so that I could get some house cleaning done for the week. When I was done I came back out into the Hangar to finish off the tasks I wanted to get done this weekend, stiffeners, fuel caps & drains. I cleaned up the fuel cap flange, the fuel drain and the fuel vent clip that gets attached to the fuel cap flange.

The deluxe fuel cap flanges have various thicknesses due to the curve of the skin. So they have several different length rivets that are needed. I grabbed those and cleaned them with MEK and laid them out so I knew which was which.

I then put them where they belonged and taped them in place.

With those all set I decided to start with the tank drains first. They are pretty straight forward to rivet. I buttered the flange and clecko’d them to the skin. I grabbed my pneumatic squeezer and started smashing away. With all the rivets set I cleaned up the mess I made and grabbed the Semco gun to hit the shop heads of the rivets. It’s important to leave the space between the rivet shop heads as this is the route that water in the fuel tank will flow to the drain, water is heavier that aviation fuel and therefore sinks to the bottom of the tanks. The drain allows a way for it to be drained off.

Next up was to get the fuel cap flanges done so I grabbed the back rivet set and steal plate. These went fairly well but I had two rivets that just didn’t sit flat so I drilled them out and redid them. That process is not fun under normal circumstances and add ProSeal in the mix and it adds a whole lot of extra fun! Once they were set I cleaned the mess up again and covered all the shop heads and made a nice filet around the inside flange.

All in all I think they turned out fine, there are a couple of rivets on the fuel flange that are set a little high but I can live with them and I think once the plane is painted you will never know. I will let these sit for a few days to let the ProSeal cure before I start on the ribs. What a great weekend in the Hangar! Looking forward to continuing the sealing and having this task behind me.

Print Friendly, PDF & Email