Build hours: 436
In the last working post, we decided to order and wait for the canopies to arrive before continuing. While waiting, we decided to build the fuel tanks using leftover .016 6061 aluminum and pop riveted construction. Inspiration came from
Thanks Mr. Hoover!
Plywood/particle board forms for the tank front and back bulkheads were made from the plan layouts and the tank front and back were formed with 1/2" flanges. The tank bottom was cut out and bent per the plans. The tank parts weigh 1.25 lbs - which should be 1/2 the weight of the .032 5052 welded tank. Total cost was less than $95 dollars per tank.
Plan note:
Check the front and back bulkhead forms for proper clearance under the skin (approx 1/4" allows for padding under the tank on the rails and over the tank top under the skin) . The first rear tank bulkhead came out against the tank skin and the form had to be adjusted and the bulkhead remade.
After forming, the bulkheads were clecoed to the bottom. The front bulkhead flanges were turned in and the rear bulkhead flanges were turned out to accomodate the flange angles after forming an the tank slope. The tank top template was fitted and trimmed. The tank top was then cut, drilled and clecoed. One inch rivet spacing (117 total) was used and the rivet holes were dimpled to accept AAC rivets. The tanks will be completed by using red ScotchBrite and MEK or Alumiprep etching to clean the rivet lines and a generic ProSeal Epoxy from Van's Aircraft to seal the tank. No sloshing required!
An aluminum filler flange was found online from
and an AN867-3 was used for the outlet. The AN867-3 flange required turning on a lathe to remove the turned up edge and provide a wider flange.