We call it a "Tile Press" but, when you consider all the shapes you can make with it, maybe we should call it the North Star Clay Press! We've made bowls, light switch plates, candle holders, trivets,
medallions, and drink coasters so far!
Here is the first hand-operated press for the potter and school that uses air to gently
and quickly release the finished part.
Air release pressing has been used by industry for decades for good reason. It's fast, produces nearly perfect ware requiring little or no fettling and requires only one or two dies ("molds") unlike slip casting or jiggering. Such presses have until now been hydraulically operated and too big, too heavy and too expensive for the potter. Moreover, they were very costly to tool up and could present substantial danger to the operator and bystanders.
The North Star Tile Press offers nearly the speed and all the quality and versatility of industrial presses but in a smaller, much less expensive configuration that is inherently safe in any setting. Thanks to the massive solid steel gear drive, no great physical strength is required of the operator. Within its size constraints, this press can turn out just about anything that has no undercuts: plain and decorated floor and wall tiles, saucers, small cups, bowls, ashtrays, spoon rests, electronic parts, switch plates, sprigs, handles, knobs and much more at upwards of 100 pieces per hour - all perfectly formed.
You can make your own dies or use stock dies. You can use just about any throwing clay to faithfully reproduce any raised or impressed decoration. And you'll do it easier and faster than ever thought possible.
WHAT'S THE DIFFERENCE BETWEEN A DIE AND A MOLD?
Potters and artists often use the words interchangeably, but there is a difference. Here are over-simplified, but workable definitions as they apply to the tile press: A mold is made of soft plaster, such as Potter Plaster #1. The inside of the mold is usually shaped like the outside of the piece to be made. Molds are absorbent and designed to "pull" water from the clay. It is usually used only once before it must be allowed to dry, so a great many molds are required for production.
A die, on the other hand, is made from gypsum cement (often called "hard plaster") such as CeramicalTM or HydrostoneTM and it uses clay of throwing consistency which is not further wetted. The die forms the clay in exactly the same way as a sheet of steel is stamped into an automobile fender. Dies have two halves, one to form the bottom of, say, a saucer and one to form the top. These two halves are brought together with a ball of clay between them. Within each half there is buried a porous tube. When air is sent into it, the air escapes and pushes water, which is resident in the "plaster" toward the clay, releasing it from the die. The bottom usually released first, the upper half of the die is then raised with the formed piece clinging to it. A bat or other material is held under the upper half of the die and the tube in that part is pressurized. The formed clay is released and caught very gently with the bat.
Please note again, that this is greatly simplified. Today there are many other die materials and techniques, but they are largely, if not completely, out of reach of the potter's studio or classroom.
METHOD OF USE
A two-part die (or "mold") made of "hard plaster" (actually gypsum cement such as CeramicalTM or HydrostoneTM) is mounted on the bottom and center plates and aligned. A wad of clay is placed in the bottom half and the Wagon Wheel Handle is rotated to bring the two halves of the die together. As they come together, the clay is forced to take on the shape of the die. A small puff of compressed air is fed into the bottom half of the die to release the formed clay. The Wagon Wheel is rotated backward to raise the center plate and the top half of the die with the formed clay clinging to it. A bat is then held under the clay while a puff of air is fed into that half of the die, releasing the formed piece to be caught with the bat. That piece is set aside to dry and the process can be immediately repeated.
The press comprises three aluminum floor plates, each reinforced with 1/2 inch machined steel stiffeners. The top and bottom plates reside at the ends of three 1 inch steel uprights.
The center plate is driven up and down by a Wagon Wheel handle turning a massive solid steel 6-pitch rack-and-pinion gear train.
Air from nearly any compressor is fed through a 3-way valve, alternately to the lower and upper die halves to release the formed part.
Shipping: Via United Parcel Service in three cartons of 147, 10 and 8 pounds.
Max "daylight" stroke: 12 inches
Max diameter of impression: 5-1/2 inches wet
Rings: 8-1/4 inch ID by 2 inches high
Clay required: Any throwing clay (though very groggy clays will shorten the life of the die)
Overall dimensions: 12 x 12 x 28 inches high (including rack)
Minimum workspace required: 30 x 30 inches
(Press must be securely fastened to sturdy bench or built-in table).