Tank Baffle Prep

Time: 6 Hours

Today started with the weekend breakfast with the fellow builders and a little hangar talk. I always enjoy these days as I can run my weekly work and questions by the guys to see how my progress is coming. One other thing I wanted to do this morning was to drive to Monee, IL which is south of Chicago to an airpark called MeadowCreek (2IL9) and have a look. This is a beautiful airpark where you can build, or buy, a home with a built in hangar and live with your plane. It’s a gated community and the roads/runway are private. All the roads are also taxiways, so cars give way to any aircraft. You can wake up and open the garage door and just go fly, a complete dream for me! I had the opportunity to meet a resident there and learn that she is a realtor/pilot. It was a great little trip and will be something that I look at for the future. When I got home I was pumped up to get into the Hangar and start working. First up was to finish up all the interior tank items that need taken care if before you can finally seal up the tanks with the rear baffles. I started with finishing the wiring for the fuel capacitor plates. The outboard wire was already in place but I needed to fish the inboard wire through the bushing that has the vent line in it. This was a tight fit and took a little time to get done. Once there I made some measurements and cut them to the correct length. I then crimped the ring terminals on each of them and checked their security.


20140308-192811.jpgIt’s pretty tight in this bay to attach these wires to the plate since they are cut to the right length. I left a little extra length and will rotate the bushings in turn wrapping the wires around the vent line taking up the slack.

20140308-192953.jpgWith the wires all connected I grabbed the screws and the required hardware to attach the plates. Remember that these plates must be deprecate from the fuel tank structure as far as the metal is concerned. So you must isolate them with plastic pieces. The screw is placed in a tube and the tube is placed in 4 plastic washers. This isolates the screw and plate from touching the rib that it’s attached to.


20140308-193315.jpgBefore I did the final attaching I tested the continuity of the plates with my Ohms meter. I placed the tips one each plate and got a tone. I then placed one on a plate and the other on the tank structure with no tone. Touch two placed of the structure gets a tone. I also hit the center of the BNC connector and the plates with a tone. This all proves that there is no contact with the plates and the tank structure. Once that test was done I mixed up a little ProSeal and covered the terminals to seal them up followed by attaching them to the ribs.

20140308-193901.jpgThe slack was then removed from the wires and I added a blob of ProSeal about every 2 inches to secure the wire to the vent line.


20140308-194111.jpgI then attached the corner anti-hangup guides for the flop tubes with a couple of LP4-3 pop rivets.


20140308-194311.jpgThe last item in the interior was to bend up the tip of the fuel bent so that it is at the highest point of the tank. The vent will replace the fuel with air as it’s used, but it also allows the fuel to escape overboard as the fuel expands in the heat. With out this vent your tank would crush in as fuel is used and pop as the fuel heated up.

20140308-204836.jpgThose were all the remaining items inside the tanks so I grabbed the MEK and cleaned all the parts that would get sealed with the baffles. In prep for the baffles and the z-brackets that go on them I marked the proper orientation of the brackets on the skin. Putting them on in the wrong configuration would really suck. So I drew the correct orientation on the skin for quick reference.

20140308-205636.jpgThose brackets get pop riveted and if you remembered in an earlier post when starting the tanks I moved the rivet holes on the bracket flange to make it easier to pop rivet. Even with that adjustment it is still tight so you have to grind the face off a cheap rivet puller to get to them.

20140308-205917.jpgSo I decided to stop there so that if I forgot any item that needed taken care of I will remember it in the middle of the night! So tomorrow will be the big day and finish the tanks. That will give them a full week to cure and I will grab some 100LL to fill and leak test them.

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