The manual training school, comprising a full statement of its aims, methods, and results, with figured drawings of shop exercises in woods and metals . hem. Until dried they should be handled as little aspossible and be carried on small iron or tin plates. In ordinary foundry practice, cores are all prepared by acore-maker, the molder having nothing to do with their designor construction. In school-work, however, it is best to havethe cores prepared by the jDupils themselves. This being donethe next step is Mold{7ig. We will follow the steps of molding the form shown in , assuming the
The manual training school, comprising a full statement of its aims, methods, and results, with figured drawings of shop exercises in woods and metals . hem. Until dried they should be handled as little aspossible and be carried on small iron or tin plates. In ordinary foundry practice, cores are all prepared by acore-maker, the molder having nothing to do with their designor construction. In school-work, however, it is best to havethe cores prepared by the jDupils themselves. This being donethe next step is Mold{7ig. We will follow the steps of molding the form shown in , assuming the pattern to be in two parts divided at theparting-line. The first completed step is shown in Fig. 112. The mold-board was laid on the cross-sticks and the dragplaced upon it bottom up. The lower portion of the patternwas then laid on the mold-board. The molding-sand is nowsifted into the drag and rammed around the pattern, care beingtaken to have plenty of sand, to ram uniformly, and to avoid €hap. m] MAKING A MOLD. 115 layers. When somewhat more than full, the upper surface isscraped off with a ^straight edge, and the bottom-board laid on. drag. mold-boari Fig. 112. LowEu Half of Pattern in Drag. Now comes the second step. The whole is carefully turnedover and the mold-board is laid aside. The upper part of thepattern is now laid in place, guided by the little pins, and thecope is put on, guided^by its plates, over the pins on the thin layer of parting-sand is dusted over the whole. Arunner plug which molds a passage for pouring is set up nearthe pattern, and the sand is filled in and rammed, a riser plug
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmanualt, bookyear1906
