Light Thin Castings Industry

Fitted Goods.

The moulding process for fitted goods is in principle exactly similar to that for unfitted goods except that in the case of a perfectly flat casting a core is not required.

From the moulding shop these castings are sent, like the others, to the dressing shop, where the rough edges are taken off. Thence after inspection they pass to the grinding mill, where they are ground and buffed to give the necessary polished sur faces. They are then taken first to the fitting shop, where they are given a preliminary fitting and slight inequalities are rem edied, and secondly to the finishing shop, where the individual parts are blacked, oxidized, or nickel plated, according to require ments. Thereafter they are returned to the fitting shop for final assembly. The article is then ready for the showroom or for despatch.

Baths and Sanitary a moulding process similar to that previously described, the bath is annealed or burned, i.e., heated in a furnace known as a muffle. The purpose of annealing is to soften the metal and in particular to remove or drive out all of the various gases which may remain imprisoned in it. The bath is then dressed, sand blasted, and coated, to give a suitable ground to which the enamel can adhere. It next pass es to the enamelling shop, where it is again put into the muffle and kept there until it is at the requisite heat. It is then taken out and the enamel, which is in powder form, is dusted on by means of automatic dusters or fine mesh sieves. Generally each bath receives two coats of enamel, each coat being preceded by the heating process. The bath is then laid aside for the enamel to harden, and thereaf ter the feet are bolted on and the outside painted. The bath is then ready for the warehouse or for des patch.

Cisterns are simply moulded, dressed, fitted, and painted, while sinks are enamelled by a process similar to that followed in the case of baths. The cast-iron porcelain enamelled sink has, how ever, been largely superseded by the earthenware sink.

With regard to hollow-ware and structural and ornamental castings, the process, apart from moulding, follows the lines de scribed on p. 85, namely, dressing, tinning or enamelling, in the case of pots and pans, and in the case of spiral stairs, verandahs, shop fronts, etc., dressing and fitting.

Plate Moulding.

A development in the moulding process is the use of plate patterns. Instead of working with a loose pat tern, one, two, or more articles, where the size and nature of the casting lend themselves to it, are put on what is known as a plate. At first these plates were made of cast-iron, but they have since been made, where possible, of aluminium, so as to lighten the handling of the job. There is, however, no differ

ence in the actual moulding process, and successive processes follow, as before described, according to the nature of the article.

Machine Moulding.

For a considerable time machines have been employed to assist in the ramming of the moulds, but for merly these were chiefly used for smaller classes of work, e.g., con nections and certain types of flat castings. They are variously operated—by electricity, by compressed air, by hydraulic power, or by hand. In all cases the moulding box has to be filled by hand, the machine doing only the ramming. Since the World War, however, there has been put on the market a machine called the Sand Slinger which is being operated in foundries throughout the world. This machine not only fills the boxes with sand but, in the act of doing so, rams it hard. It is made to different de signs for different purposes and can ram practically any size of box at speeds varying from five to ten cubic feet of sand per minute. The type most commonly in use in light castings shops is known as the Tractor machine. This takes the sand from the floor, riddles it and passes it on by means of a moving belt to the ramming head, whence it is discharged into the moulding box. The ramming head is attached to the end of a swivelling arm which has a radius of from 9 to 11 ft. on either side of the ma chine. The machine is also made to work in a stationary position, in which case it is bolted to the floor of the moulding shop. It is also supplied in portable form so that it can be moved to any job in any part of the moulding shop. In the case of the stationary and portable types the sand has to be fed to the machine. Another type is the Motive type to which is attached a large tank with a sand carrying capacity of from eight to ten tons. This can con veniently be filled by means of an overhead conveyor.

As the ramming of the boxes in the moulding shop is one of the heaviest and most tiring jobs in the foundry, it would appear to be only a question of time before practically all classes of work are automatically rammed by the Sand Slinger or some similar type of machine. (J. K.) LIGHTER, a barge employed in ports in loading or unloading the cargoes of ships, the name being derived from the verb "to light"; i.e., to relieve of a burden. The men employed on them are termed lightermen. (See BARGES AND CANAL CRAFT.) Also a small mechanism, used instead of matches, in which a small wheel is twirled against a piece of ferro-cerium, throwing off sparks which ignite petrol fed through a cotton wick.