how long do you wait to let the por 15 dry/set before re installing the fuel tank?What kind of solvent did you use?How about gasoline as a solvent or alchohol?

You would have to read the POR15 directions to see how long it takes before you can use it.
I use gasoline as solvent but it is a bit dangerous. You can make a lot of ignitable fumes in a short amount of time.