what I might ask the Pelseal guy is:
Suppose you took a steel auto tank and coated it inside and out, what would happen in the briney, how long til corrosion set in, etc? And up the metal tank scale.
In the original conversation I didn't think to ask if the stuff was so good inside why not outside?

The Pelseal "bonds" to aluminum, ss, copper, brass, concrete glass, ceramics, Viton (ie, itself) and other elastomers. It comes as a coating, adhesive, sealant and caulk. Comes in colors including white, and can be color matched! One year shelf life.

2-part pot life of 4 to 8 hours, heat accelerates the cure. Almost too good to be true. Quart kit goes for $150. The catylist is solvent based so it has to ship hazmaat.

But the reat question is:
How long does it last in the tank?

Ok for the gas. Now, How About a Sealer For Potable Water Tanks ?