Show I I I l I I T TO RE REMOVE SCALE I FROM WATER ATER BACKS Circulation and Heating of 01 Wat Water r Is Retarded Prepared by tho the United States Department of A Agriculture Hard water causes causes a limy deposit or scale on the inside of water backs and heating coils calls I If allowed to accumulate accumulate accumulate late the scale retards the circulation and heating of the water and by closure of the Ule bore may prove danger danger- ous Moreover continued neglect makes it Increasingly difficult to r re remove re remove move the scale The water back or coil call should be removed from the fire box says the United States Department of or ture At the time union or other Joints nearest the fire box disconnect nil all pipes and unscrew them from the Water water water wa wa- ter back If there is a R clamp which holds the fire-brick fire lining against the thc oven loosen It and remove side and end linings Lift out the water back and take it out on the ground Soft scale or sludge may be removed by pounding the time water back with a mallet or hammer and then flushing with a strong jet of water A long gouge or chisel Is used on those surfaces that can cnn be reached Sometimes the water back Is heated In fn a blacksmiths blacksmith's forge and then pounded but unless carefully done this treatment may break It Some householders keep a spare water back for use while the other Is being cleaned Waters Vaters of or varying chemical al composition composItion composition compo compo- cause scale differing In composition composition composition compo compo- and hardness Ordinary limestone limestone lime lime- stone calcium carbonate scale If not of excessive thickness may readily be removed with acid neld Gypsum Gyp Gyp- Gyp Gypsum sum calcium sulphate scale Is hard and resistant and with other constituents constituents In their more compact forms Is little affected by acid The Time water back should b be laid on the ground and filled with a strong solution solution solution tion of the time acid in water The strength of the solution should vary with the tike amount of deposit the ordinary mixture mixture mixture mix mix- ture being one part of acid and five to seven seyen parts of water If the time deposit deposit deposit de de- posit Is Isery very ery thick the acid needs little lit lIt- tle dilution Commercial acid in bottles containing six pounds about two and one half quarts costs 20 to 25 cents a pound The bottle bottJe should be labeled acid pot acid poi poison son and like other chemicals should be kept where children cannot get it Heating the water back bacle hastens the action of the acid At the end of ot otan an hour or two or sooner If the deposit del deI de de- posit Is dissolved ed pour the solution from the time water back bacle and flush It thoroughly thoroughly thoroughly thor thor- with hot water to remove tho the acid If all the deposit has not been removed repeat the operation makIng makIng making mak mak- ing sure that the acid Is completely washed out before replacing the theater water ater back Similar methods may be used with copper coils Place the coil coB or heater on two sticks over oyer a large bowl With the aid of a lead funnel pour the acid solution down through the c coil coll ll Dip tbs tan bowl and continue to circulate circulate late the sol solution through the coil coll until the deposit Is m ed d. d The coil call should then be thoroughly washed fished out with hot water The water hot flow pipe close to a a. awater water ater back or coil doll frequently becomes thickly covered with scale If the pipe Is brass It may be disconnected and treated with acid and th then n u washed out ont with hot water If It the pipe Is galvanized Iron and In bail bad b d condition It will probably be more satisfactory to Io o replace It with new pipe |