There are 13.46 gallons in 1.8 cubic feet and one gallon of water weighs about 8.34 pounds. So: 13.46 gallons x 8.34 pounds = 112.2564 pounds for one gallon of water.

A two gallon bucket of water weighs 16pounds because a pint of water weighs one pound and there are eight pints in a gallon there for two gallons of water weigh 16 pounds