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The E-Sylum: Volume 23, Number 34, August 23, 2020, Article 16

VOCABULARY TERMS: MOLD, MOLDING

Dick Johnson submitted this entry from his Encyclopedia of Coin and Medal Terminology. Thanks. Elsewhere in this issue is an article on this topic at Colonial Williamsburg. -Editor

Mold, Molding. The matrix containing the cavities to form a cast piece, and the process of producing that piece. The material to form the casting must be molten, the mold must be capable of sustaining heat and holding the form until the molten material solidifies. There are several kinds of molds, they differ in what they are made of and what they produce. Also molds can be used for only a single cast, these differ from production run casting, where a permanent mold is made often of two or more metal parts for repeated use. The use of molds for medallic production is rather limited, many types of molds have little concern to this field.

Types of molds. Molds can be made of a variety of material – called the investment – these can be metal, ceramic, rubber, plaster, epoxy, gelatin, silicone, and, or other. Since numismatic items are concerned with sharp, fine, minute detail, several of these investments, like sand, are not suitable for casting of numismatic or medallic items.

Lost wax, (cire-perdue) is a waste wax or waste mold type and is suitable for medallic castings. flexible mold, made of gelatin, rubber or silicon are suitable for casts with undercuts; ideal for medallic plaques. Others – like piece mold – which are used for sculpture in the round – have no application in the numismatic field.

The pattern from which the mold is made can be a variety of materials. Often it is wax, plaster, or wood. Some wood patterns for coins were made in Germany in the 15th century. England made coin patterns of iron, these were cast for use on early die-cutting pantographs (which more typically would use an electroform copper pattern.)

Molds were used for the cash coins of China for centuries. These formed cash "trees" with sprues still intact from which coins were broken off. Several of these molds still exist in museums today.

See also foundry cast.

Book lovers should be word lovers as well.

Looking for the meaning of a numismatic word, or the description of a term?  Try the Newman Numismatic Portal's Numismatic Dictionary at: https://nnp.wustl.edu/library/dictionary

Or if you would like a printed copy of the complete Encyclopedia, it is available. There are 1,854 terms, on 678 pages, in The Encyclopedia of Coin and Medal Technology. Even running two a week would require more than 19 years to publish them all. If you would like an advance draft of this vital reference work it may be obtained from the author for your check of $50 sent postpaid. Dick Johnson, 139 Thompson Drive, Torrington, CT 06790.

Wayne Homren, Editor

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To submit items for publication in The E-Sylum, write to the Editor at this address: whomren@gmail.com

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