Show FIRST AP I 1 D to the AILING HOUSE by roger C whitman QUESTION how can I 1 clean the coils of my hot water heater which we use in connection with our hot water plant the heater has not been giving good results for some time and I 1 have been told that the coils are probably clogged ANSWER hydrochloric acid has been used by some plumbers to dissolve the deposit in copper coils but this is a high ly cor corrosive asive chemical and should not be handled carelessly by an inexperienced person there may be a plumber in your neighborhood who could do the cleaning for you A safer method would be to tap the coil carefully with a wooden mallet dp not strike the coil with hard blows then flush out the coil with a garden hose QUESTION Is there any way to remove a silver nitrate stain from a white sink ANSWER moisten with iodine rinse with clear water then apply a solution of photographic hypo one tablespoonful in a pint puit ot of water |