Sand Casting Mold

Project details

  • Date

     February 5, 2015

  • Task

     Study Collection

  • Category

     Featured Finds

In the summer of 2011, a mysterious object was found within a posthole of James Fort’s 1608-1617 church. There are many resources to identify objects from the past: historical texts and paintings, archaeological reports, museum collections, and antique auctions. Also important is the knowledge held by historical re-enactors and tradesmen from their first-hand experiences using things. In this case, two blacksmiths — Peter Ross working in North Carolina and Mark Atchison with Plimoth Plantation in Massachusetts — independently suggested our artifact could be a casting flask.

A flask is a type of tooling used to contain a mold in metal casting that involves molding sand. A book entitled The Theory and Practice of Goldsmithing by Prof. Dr. Erhard Brepohl and communication with Dr. Brepohl confirmed that our artifact is a mold for sand casting small objects and could date to the early 17th-century. As described by Dr. Brepohl, the sand casting mold is in two parts: the cope (which has registration pins) and the drag (which has the lugs to receive them and thereby ensure alignment of the two halves). To begin the casting process, the drag is placed on a board with the inner side down. After the drag is filled with wet sand, a mold board is placed on top of the frame, which is then flipped over. The cope is then fitted onto the drag, and the sand in the drag is dusted with a parting powder such as talc or cornstarch. The object to be molded is placed in the mold and sprinkled with parting powder before being covered with sand, which is pressed into the cope. The two halves of the mold are then separated, and the pattern for the casting is carefully removed. Finally, a channel is cut in the sand from the impression left by the pattern to an opening in the casting frame. The cope and drag are once again joined, and the sand is permitted to slowly dry before the liquid metal to be cast is poured into the mold. After a few minutes the frame can be separated and the casting removed.

This sand casting mold used by goldsmiths and jewelers would have been among the “appurtenances” disdainfully mentioned by Captain John Smith as superfluous to the welfare and survival of the colony. Sent to Jamestown by the Virginia Company, the goldsmiths and jewelers arrived with the equipment they needed to set up workshops so they could function in the settlement as they did back in England. But was the operation intended to test the quality and viability of Virginia’s silver, gold, or copper ores for use in jewelry? Or was it utilized to produce special small finds for the fort’s gentlemen or for sponsors of the specialists? A puddle of silver adhering to the interior base suggests that at some point the mold was used for casting silver, but it is not known whether or not this was a Virginia trial.