REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1901 r91 



ii 



MOLDING SAND: ITS USES, PROPERTIES AND 

 * OCCURRENCE 



BY EDWIN C. ECKEL 



In the preparation of the following paper, free use has been 

 made of such published sources of information as were avail- 

 able, the more important of the books and papers consulted 

 being listed at the close of this paper. In addition to these 

 published discussions of the subject, Dr F. J. H. Merrill has 

 placed at the disposal of the writer the material accumulated 

 by Mr J. N. Nevius while assistant in the State Museum. Mr 

 Nevius's notes relate almost entirely to the local details of the 

 deposits in Albany county and have been of great service to 

 the present writer. 



The uses of molding sands 



Molding sands or closely similar materials are employed in 

 making castings when metallic molds are not used. The spaces 

 to be filled by the castings are formed usually by pressing a 

 pattern into the molding material, removing the pattern as soon 

 as the proper imprint has been made in the sand. The pattern 

 is usually made of wood and must be an exact counterpart of 

 the casting which is to be made. In case the casting is to have 

 recesses, or holes, such spaces must be provided for by putting 

 suitable cores in the molds. The cores are commonly made of 

 clayey sand or loam. Short cores can be made from rock sand, 

 the material resulting from the decay of rock in place; but 

 longer cores require the addition of seashore sand in order to 

 secure sufficient porosity. Occasionally patterns are dispensed 

 with, the workman forming the mold in the sand either by hand 

 or by the use of mechanical contrivances. Commonly the mold- 

 ing material is held in two boxes, clamped together when in use, 

 about half the mold being in each box. In this case, as the top 

 box must be removed temporarily in order to take out the 

 wooden pattern, a layer of " parting sand " is dusted over the 

 top of the molding material held in the lower box. This so called 



