Q. I have built a 6-by-8-by-6-foot concrete reservoir in which to store water. A builder tells me I should coat the inside walls with an epoxy paint so as to prevent seepage through the walls and floor. In cold weather the water could freeze and do damage to the concrete. What epoxy is not toxic to humans or animals? Harold A. Bailey Carthage, N.C.
A. We are told that glycidated resins, cycloaliphatic resins, and epoxydized resins (most commercially used epoxies) have serious limitations, including pot life, cure sensitivity, toxicity, and high costs.
Among others, Sealwall Products Inc. makes a low-cost cementious, nontoxic waterproof coating. An acrylic modifier for cement is used to bind it to the concrete tank and, says the manufacturer, the coating may be applied inside or out. The company is at 36300 Lakeland Boulevard, Eastlake, Ohio 44094. The phone number is (216) 951-3445.
The Sealwall people say they would be glad to help you on specifics as to the step-by-step process to waterproof the storage tank with a nontoxic sealer.
Should any reader know of a perfectly safe waterproofing epoxy to use on a domestic concrete water tank, send it to this column, care of the real estate editor, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115.