Final Prep (Dimple, Countersink, and Shape) 12/19/22 – 1.5h The fuel level sender unit for each tank comes with a float attached to the end of a long 3/32” wire that has to be bent to fit the tank and provide a full range of motion from empty to full. The plans include a 1:1 scale isometric drawing of the wire geometry, which makes it easy to measure the bend locations. WARNING: The plans were updated with new dimensions for the float wire on 3/26/21. Make sure you are using the latest version of the plans! I used my electronic plans to lay out the bend locations, and fortunately noticed my electronic plans did not match my printed plans in the shop before I made any bends. The printed plans were correct, and the bend locations were updated on the float wires. I looked at a few options to make the bends, and finally decided to go the simple route of clamping the wire in a bench vise at the bend point, and then hand-bending the wire with a wooden block to help keep the wire straight during the bending process. This method worked really well, and I ended up with nice 90-degree bends right where I wanted them. The bends for both the left and right float wires are the same, and the only difference between the two is the orientation of the float. The left float faces forward in the tank, and the right float faces aft. [Bench Vise] Assemble 12/20/22 – 0.9h 12/21/22 – 2.1h I temporarily installed the fuel senders to ensure the float wire geometry was correct. Each wire needed a little tweak to avoid hitting the top skin, which I think was caused by the factory bend at the shepherd's crook not going quite far enough. The result was a slightly sharper than 90-degree bend at the middle of the wire. I also noticed the end of the float wire extends through the sender unit by about 1/16 to 1/8 of an inch. I'm a little concerned by that since the exposed end rubs against one of the sender wires. I'll either try to move the wire a bit to avoid the contact, or trim the float wire flush with the hole in the sender. The temporary installation is also a good time to test the electrical function of the senders. I checked for continuity between the sender ground plate and the skin of the tank, and I measured the change in electrical resistance as the float travelled between the full and empty positions. The left sender had a range of 30 ohms full to 240 ohms empty, and the right sender was 30 to 246 ohms. Final installation starts by applying sealant to the exterior of the aft inboard ribs where the fuel sender will be installed. The instructions call for a 1/16 inch thick layer of sealant, which will later be compressed to a 1/32 inch layer when the sender gets torqued down. I started by putting clecos into each of the nut plate holes to keep the sealant away from the fuel sender installation screws. The screws provide the ground path from the nut plates to the sender ground plate, and I didn't want sealant to interfere with the electrical continuity. I also wrapped the fuel senders in plastic to keep them free from excess sealant while I maneuvered them into place. I removed the clecos after applying the sealant to the rib, and then visually aligned the fuel sender with the holes. I applied Locktite 565 to each of the screws to provide a fuel seal on the threads, and then tightened the screws evenly until the sender was firmly embedded in the sealant. I formed a fillet around the exterior of the fuel sender and confirmed there was a continuous squeeze-out bead of sealant around the interior hole. I may go back later and encapsulate the screws to add an extra layer of leak protection to the Locktite. The final step was to check for continuity between the ground plate on the fuel level sender and the skin, which checked good on both tanks. [Allen Wrench, Multi-meter, Locktite 565]