BTW I wasn't trying to sound clever.. I can assure you these are no more than the fundamentals. My point was to encourage you to treat this with some suspicion until you have some evidence there is any fact to it. I know just enough about polymers to be dangerous, but the little I do know makes me automatically skeptical until I see some data that legitimizes the claim.
I would feel safe with any automotive two part polyurethane system until proven otherwise (fuel proof wise I mean).
The danger is - other than the usual health and safety cautions with solvents and spraying - don't ingest, breath, or coat your skin with isocyanates, unless you really enjoy serious allergic reactions such as anaphylaxis. I got the T-shirt a long time ago - my arm and face swelled up until I looked like a pimply raccoon. Shot of epinephrine in the leg, shake for a couple of minutes, then sweet relief..
.