Abstract: Cylindrical water tanks, such as used for water softeners, inherently corrode at the bottom and herein is taught that the tanks are repaired by removing the bottom dish with the use of a novel tool that moves around the tank and bears there against with a substantially uniform force thereby readily following the tank's contour, by sandblasting the interior for cleaning, by installing a new bottom dish to the cylindrical body with the use of a novel tool that automatically stops further penetration of the dish into the tank when a predetermined overall height of the tank is obtained, by welding the bottom dish to the body, by coating the interior with a non-corrosive plastic with the use of a novel spray gun apparatus that radially sprays the liquid plastic onto the inner walls of the tank as the spray nozzle moves axially therein and then the spray nozzle is adjusted to cause the spray to form an upward diverging cone to coat the underside of the top cover, and finally by allowing the plastic to harden.

Abstract: Cylindrical water tanks, such as used for water softeners, inherently corrode at the bottom and herein is taught that the tanks are repaired by removing the bottom dish with the use of a novel tool that moves around the tank and bears thereagainst with a substantially uniform force thereby readily following the tank's contour, by sandblasting the interior for cleaning, by installing a new bottom dish to the cylindrical body with the use of a novel tool that automatically stops further penetration of the dish into the tank when a predetermined overall height of the tank is obtained, by welding the bottom dish to the body, by coating the interior with a non-corrosive plastic with the use of a novel spray gun apparatus that radially sprays the liquid plastic onto the inner walls of the tank as the spray nozzle moves axially therein and then the spray nozzle is adjusted to cause the spray to form an upward diverging cone to coat the underside of the top cover, and finally by allowing the plastic to harden.