I'm building a water tank and I'm looking for a large fill cap bigger than a fuel cell cap .
My tank was just a 5 gallon aluminum fuel cell. I bought some thin styrofoam from home depot, glued it on all sides of the cell, then coated the cell with aluminized bubblewrap, and taped up the seams with aluminum ducting tape. Keeps the condensation in!where did you get the stuff to wrap the outside of tank?When you made your tank what size fittings do you use and where are the placed ? what thick ness aluminum for the tank ?