Bookbinding and its auxiliary branches . per cent of these com-plaints are due to the glue-melting pots not having beencleaned for months, or to the carelessness of the workerin permitting continuous boiling. The glue tank with six pots and a large kettle in thecenter which is commonly used in bookbinderies ought tobe condemned, as the constant evaporation causes the glueto thicken and skin. Uniform heat can not be kept;and not infrequently the tank is allowed to boil over. Theglue waste is enormous in proportion to the consumption. The ideal cooker is one that has a water jacket andair-tight
Bookbinding and its auxiliary branches . per cent of these com-plaints are due to the glue-melting pots not having beencleaned for months, or to the carelessness of the workerin permitting continuous boiling. The glue tank with six pots and a large kettle in thecenter which is commonly used in bookbinderies ought tobe condemned, as the constant evaporation causes the glueto thicken and skin. Uniform heat can not be kept;and not infrequently the tank is allowed to boil over. Theglue waste is enormous in proportion to the consumption. The ideal cooker is one that has a water jacket andair-tight glue chamber. The glue is drawn into the indi- 70 BOOKBINDING vidual pots from a faucet. The water jacket is kept at auniform heat by steam seepage through a siphon andthe water level is automatic by means of a return pipe. The glue is never boiled, does not thicken or skin, andcan be kept for two weeks without material injury. The ideal pot is the electric-heated copper pot set ina cast-iron water jacket. Deep glue pots are responsible. liiili\i(lual Electric Glue Pots. for much waste of time in cleaning the hands and handlebefore using. Glue is purchased in flakes, sheets, cakes, strips, rib-bons, or in pulverized form. In soaking glue, it is neces-sary to immerse all in water, as protruding pieces requireconsiderable heat to dissolve, and tend to spoil the glue must be soaked in the same manner andrequires frequent stirring. The erroneous opinion pre- GLUE 71 vails that ground glue is an inferior article which con-tains sawdust and floor sweepings. Manufacturers canill afford to sell an inferior article for first-class material. Some large binderies heat the glue in a large vesselwith direct steam, and the workmen have small potswhich are filled from this. Direct steam is injurious tosolution of glue; the drastic action of the steam weakensit. If the best glue is continuously boiled with directsteam for twenty-four hours, the gelatinizing power ofthe glue will be
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbookbinding, bookyear
