The Mold Press, made only by North Star Equipment, is an entirely new tool designed to easily and accurately reproduce small one-sided shapes at up to 100 pieces an hour. It is intended to be an inexpensive alternative for the experience potter who needs more production and accuracy than can be achieved by hand but who is not ready for industrial equipment.
This press is especially useful for sprig molds, jewelry parts, buttons, hardware items and other special shapes. Such pieces can contain almost any decoration on one side, which will be reproduced faithfully.
A mold form provided with the press is used to make original working molds of hard plaster such as Hydrostone or Ultracal. In most cases only one working mold, and a backup will be required, and each should yield from 2,000 to 15,000 or more impressions, depending on the complexity of detail and the tooth of the clay.
The piece to be reproduced is sculpted in positive in the bottom of the mold form, given a heavy coat of mold release, and plaster poured over it. The plaster is allowed to harden, shaken out of the form and, after thorough drying, used directly in the press. An existing object may also be placed in the form and cast over, or a solid plaster form can be cast and the impression carved into it after hardening.
The piece to be reproduced may be any shape (though regular squares and rectangles are most difficult) and contain almost any relief or decoration, so long as there are no undercuts and the back of the piece is flat. While the press can accept a larger mold cavity, it is strongly suggested that users at first limit themselves to 14 square inches of impression or less, and to go beyond 20 square inches only after experience and then with extreme caution. It should also be noted that precise thickness control is not possible with this small press. Variation of 1/32 inches, while not visible in most applications for which the press is intended, are not uncommon.
HOW THE PRESS IS USED
A mold fastened on the center plate is sprayed with mold release. A measured amount of clay is placed in the mold cavity. The handles are then depressed and the center plate is lifted by four sets of toggles. Clay and mold are squeezed against a Masonite bat held in guides on the top plate. The handles are returned, dropping the center plate and the mold, leaving the formed clay adhering to the bat. That bat is removed and set aside to dry. Another is inserted and the process can be repeated immediately.
Major components are of high strength cast aluminum and machined parts are of special high-strength steel alloy. Typical construction tolerances are less than 0.001 inches.
MOLD RELEASE AGENTS
When hard plaster molds are used, silicon spray mold release is used. WD 40, which is inexpensive and available everywhere, works as well as any. In rare cases where soft plaster must be used or when it is necessary to protect molds from wear, a stretch film such as Saran Wrap is sometimes used.
The bats used are simple 8" x 10" rectangles of 1/4" Masonite, Duron or any similar material.
The press comes complete and ready to work with one sample mold, mold form, 13 bats, complete instructions, hardware and one can of mold release.
|Mold Press Bats12 Mold Press Bats.|