I'm happy to report that the silicone around the rubber seal did the trick - 48 hours full of windshield washer fluid and not a single drop!
The tank holds almost 1/3 of a gallon - it sure didn't look that big when I built it
Lives in garage:
2004 Red Jeep TJ "X", big tires, suspension, stereo delete, dent in cowl.
1982 Red Jeep Scrambler, small block chevy on 35's.
"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety." -Benjamin Franklin