I see your point, Powderman, but reversing the semantics changes the probability. Stated as you re-stated it, its an indication it will fail, not if it will fail. Probable versus possible.
I can tell right now, I'm soaking a tank for SohRon with 4.5 gallons of acetone on a tank lined with Caswell. Its not even budging it. I'll have to drain it and step up to MEK to evacuate the tank of the liner. If Caswell can sit for over 24 filed with Acetone and not weaken, dissolve or separate, then its pretty darn tough by me. You can refer to his thread as to the "why he lined it" and how it has now 2 layers in it.