[Normagain]

I had mine done in .190 aluminum which is 3/16". Mine is 72" X 23" X 10" and holds 68.8 gallons accounting for thickness of material if my calculator is correct. The floor is getting raised over two inches to accommodate the tank. Factory is 60" X 24" X 8", 1/8" thick. The place I had mine fabricated, American Tanks does most tanks in 3/16". It is plenty thick in my opinion, very sturdy and a bit heavy. 1/4" would weigh quite a bit more! Here are a few pictures of mine, one is a dry fit to make sure my floor will be high enough to clear everything. I also used it to weigh down 1/4 inch Coosa board when I epoxied that in place in order to get a nice even surface. The factory tank had three thin neoprene strips running the length of the tank. My place welded on three aluminum strips going the other direction and will have neoprene stuck to them with contact cement. Foaming in is not the best way to do it if you want it to last. The metal needs to be able to breath so water does not collect and corrode the tank. The reason I used 23" width by the way is I am sistering 3/4 marine ply all along the stringer sides where the tank is. Epoxied in place this should give the screws a good bite to hold the tank steady.