Columbus Paper - Laboratory Testing of Sands, Cores and Core Binders (with Discussion)

There is a tendency on the part of practical foundrymen to accept with reluctance the results of tests on sands, binders, and such materials made in the chemical laboratory alone. They feel that such tests frequently emphasize and measure properties that are of minor importance and fail to take account of characteristics that are important in determining the value of the material in actual practice. Experience seems to indicate that the most thorough and conclusive test for any new foundry material is an actual run in the foundry alongside of a standard material of known value. Such a test, however, involves certain difficulties and necessitates certain precautions. It is not always easy to obtain a fail trial for a new material. We all have certain prejuclices, which unconsciously affect our judgment to a marked degree. A practical test frequently involves so many workmen, each of whom reacts in a different manner to the test, that the personal equation becomes very complex and the true results of the test are obscured. There are times, too, when a thorough experimental trial of a material would interfere too much with the. rush of work in a department or would hazard the quality of the product to such an extent as to make it inadvisable. Under such conditions a laboratory test is advisable before the material is sent into the foundry. These tests should be made as practical as possible and so closely related to foundry practice as to give a true index to the value of a product for the purpose desired. Core sands and molding sands are as numerous "as the sands of the sea" and valy as much in quality. Old sources of supply are continually failing and new ones must be opened, so that we must continually search for new and better grades of sand. During the past year, the Ohio Brass Co. has developed tests for sands, cores, and binders which bear a close relation to the particular use to which these materials are put in the foundry and which arc fairly indicative of their value. While the tests thus far have been confined to cores and core sands, it is expected that tests for molding sand will bc developed in the future.