Maybe I am wrong, but I had the impression that the formulation of the plastic used to make up the tank that allows it to be painted versus a tank for say an enduro bike which cannot be painted due to the plastic formula is what we are at odds with. Acerbis makes both types of tanks. The one that can be painted, does not fair well to any gas. I don't know if it is a case of formulation or what is or is not done to coat the interior, but we do know that Acerbis can make a plastic tank that does not swell... It just can't be painted.
If this is the case, Ducati has three options; either build a metal tank, or make a non pervious skin for a non paintable tank like a tank shroud, or come up with an interior coating that is impervious to chemicals.
I nearly shat myself when I saw what the replacement cost of my S2R tank was. While that is a retail price, it would seem that a metal tank, mass produced, would not cost that much to put to market.
I guess it would be nice to be the fly on the wall at Ducati so as to know what the plan of action is and more importantly what they have set for time line goals. Since it has already been years of this predicament, it would seem they have hit a wall with probably the production costs of metal versus plastic tanks and the added nightmare of replacing umteen thousand existing tanks.
This all reminds me of the scene in Fight Club, where a discussion was made as to the probabilities of a car part failing and how many people must get hurt, multiplied by the cost of settlement; whereas if the cost of settlement is less than the cost of recalling a part, then the decision is to continue making said defective part as it is much more economically viable to deal with the issue on a case by case nature than to have to admit error. Passion for your money. Passion for Red....Tape.
Or I could be totally wrong and Blackie should post something offensive to put me in my place