I was concerned about the position of the flop tube after my last session in the shop.  The flop tube was wedged in the corner and was more likely to get stuck as a result of my anti-hangup guide and stiffener.  My initial thought was to add another angled piece similar to the other anti-hangup guide to the innermost rib.  First, I posted a new thread to Van’s Airforce detailing my dilemma.  Tom Albano was nice enough to send me the two pictures of his flop tube anti-hangup guide.  Simple solution!  Why didn’t I think of that? He simply added a straight section of aluminum to the existing guide.  This new piece goes from top to bottom in the tank and will surely solve my potential problem.

Here are the pictures provided by Tom:

In this shop session I set about implementing Tom’s solution.  It was fairly painless.  I was a little more lazy than him, and used pop rivets for the additional piece of aluminum, but I’m more than happy with the results. I also finished fabricating and installing the small angles used as anti-hangup guides on the outboard side (left in the picture).  

Both capacitive fuel senders have been crimped, soldered and installed.  In the picture below I’m using my new second set of hands prior to soldering. 

A few more pictures of the completed project.  I now need to seal the fuel vent, bnc connector, flop tube and access panels.  Finally, the baffles will be installed.  One more good weekend of productivity and the fuel tanks sealing should be  complete. 

Its bloody cold out in the garage.  This session was pure misery.

Completing the installation of the flop tubes, fuel quantity senders, and the vent lines was the name of the game in this shop session. One tank is completely ready to go, and the other tank only needs to have the wiring for the fuel sender plates installed.  I still need to seal each of these components, but that will be relatively quick.  Once that is complete, the tanks will be ready for the baffle to be installed!  I am hoping to get the tanks completed this weekend.  I know, I say that every weekend, but this weekend the end really is in sight!

I may have made the wire to the BNC connector a little short.  It sure made for a difficult installation of the connecting nut, however I do not think there is any undue load on the wire.  I crimped and soldered both these connections.  Proseal will also be added. 

Here you can see the BNC connection.  I soldered this connection previously, but today I added two layers of heat shrink to the connection.  Solder is fairly brittle.  The heat shrink should reduce the amount of flex in the joint over time and ensure the connection lasts for years to come.  Proseal will also help in this regard once I apply it.  

My first safety wire application.

Now we come to something I don’t like.  The anti-hangup guide I have for the access plate seems to perform the exact opposite of its job.  It would appear that the flop tube is more likely to be trapped in the lower corner of the tank.  I’ve posted this problem to Van’s Airforce forums and we’ll see what the response is.

Finally, I made the other anti-hangup guides, but did not have enough time to install.  I’m going to install with some spare pop rivets and a little pro seal.  

A good close up of the potential ‘trapped’ location of the flop tube. 

First up a little soldering work on the capacitive fuel tank connectors.  As soon as I install the end ribs, I will complete the install of the sender plates, wiring and fuel vent line and I wanted to get everything completely ready. 

I haven’t taken a lot of pictures of the fuel tank sealing because my camera is also my iPhone and I don’t want to get sealant all over it!  Today I installed all four of the end ribs.  All the ribs are now installed and sealed on both tanks.  The capacitive senders need to be screwed in place and wired.  The flop tubes and vent also need to be installed.  Then I’ll be ready to close up the tanks and move on to preparing the rest of the wing for riveting! I can’t wait to be done the tanks!  I keep the tanks in the basement where its a good deal warmer than outside to allow the sealant to cure faster.  I sure hope this thing doesn’t leak!!!!