Re: pvc gas tank
I have only used tank sealer once, on my more recent 1 gallon tank. The extra that I had to pour out of the tank I decided to pour into a cardboard box. The box held gas until it evaporated, about 1 month. The box never leaked out of the bottom. I used a 1 part sealer from NAPA. I don't remember the name, but it was blue in color and would get you high pretty quick if not in a well ventilated area.
Caution! I give opinions as if they were worth something. Use at your own risk.