Fuel Tank: Installation
The fuel tanks have to be supported inside the sponson. Note that the sides and top of the fuel tank are parallel to the inside of the sponson but the bottom is not. I suspect this was by design since it creates a deeper valley along the inside edge of the tank where the fuel pick-up is located; a good idea. But this also means that the supports on the bottom of the tank must be different heights on the inside and outside edges.
We opted to use rubber strips, ½” and ¼” thick which come in two inch wide strips. Two inch square sections were cut from these strips. The material selected came from McMaster Carr and is neoprene rubber, 40A durometer. This is a bit harder than a pencil eraser, providing some cushioning effect, but very little compression. It is also oil resistant. Part numbers: 8546K437 and 8456K435. We ordered the material that had adhesive on one side. The adhesive does not work well and would suggest ordering the same item without the adhesive.
Six blocks were used to support the bottom of the tank: three each quarter inch thick on the inside and three each half inch thick on the outside. Two blocks on the inside vertical were placed midway top to bottom, one fore and one aft. These are ¾” thick made by gluing a ¼” and ½” together. Remember to place a half inch block at the rear end to keep the tank from touching the aft bulkhead. Finally blocks were placed on the outside to tighten up the tank, left to right, as the tank was slid into place. The picture shows the blocks in place. (We removed the center vertical block after the picture was taken – not necessary).
3M black weather strip adhesive was used to secure the blocks. It works well. After applying a coat to both surfaces, it was left to dry for about ten minutes then pressed into place.
The tank is inserted, being careful not to knock the blocks loose. Wiping Griot’s car wash soap on the blocks also helps slide the tank in. When the tank is nearly all the way back, another block is glued on the outer most surface of the sponson, permitted to set up, then the tank pushed in the last couple of inches, lifting as it is guided in. Because of the angles, this block will be tighter as one pushes it lower, so it was not glued in advance. A block was added near the front on the outer most surface of the sponson after the tank was pushed all the way in, again pushing it lower to make it tighter. (That block is visible in the photo)
Finally, a length of one inch insulating foam was placed under the access plates which compresses on the tank from the top. Once the plates are screwed down the tank is secure.
