Grinding

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...on a much smaller scale. The work when small is all put into wire baskets and pickled, after which the basket with the well-pickled castings is slowly lowered into the bath of tin. This is usually done with a small tackle, and when thoroughly tinned the basket,,--is raisedandthetin allowed are t-h0„ i to drip off. The castings then dumped into a wooden chute, shown in Fig 16, which has inclined wooden shelves, as shown at a, which throw the castings violently against each other as they descend. The consequence is that the remaining surplus Fig. 17 direct contact with the, flame, thus heating readily. Above the kettle is the hoo shown at e for collecting the fumes and directing them toward the opening, shown at /, into the chimney. 31. Tinning by the Cold Process--When block tin is dissolved in hydrochloric acid and a little mercury, alloy is formed that can be readily used in tinning aTMc without heating either the tin or the work. Some ma e alloy of 1 part of tin, 6 of mercury, and 2 of zinc, by The tin and mercury are mixed together until a sott p is formed. The articles to be tinned should be cleab some of the methods previously explained, and thernTMaU with a rag dampened in hydrochloric acld-H with the should be applied to the surface at once and rubbed w hydrochloric acid. By this method it is very easy iron, steel, or copper with a complete, but thin, coa 1 then packed for shipment. The tinning furnace ordinarily used resembles a crucible furnace, and is illustrated in Fig. 17. A firebox is shown at a, with its ash-pit at b and flue for escaping gases at c. The iron kettle shown at /isin FILLING AND PAINTING MACHINE TOOLS. 32. Most machine tools are finished by giving them a coat of paint. The surfaces of the castings are cleaned first in the f...