Recently, I have been contemplating making a larger fuel tank for my wife's plated klx140. I have a lot of experience with fiberglass and have made gas tanks in the past so I know that I have the ability. The problem with a fiberglass tank involves the new ethanol fuel mixtures reacting to the fiberglass and the fact that the tank will overhang the frame and be susceptible to damage. I also make custom gun and knife holsters out of kydex for local law enforcement officers and have become pretty skilled with the material. After a brief search, it appears that kydex has no reaction to fuels of any kind, including brake fluid and jet fuel. I can easily mold the kydex around the bottom of the existing tank and then fill the mold with foam and shape a new tank before molding the top and welding them together. Is there any reason that this wouldn't work?