Place it so that one edge is held away from the table or floor by a stick about one inch thick, thus forming a slight angle to per­mit better drainage.When the clay in the mold has lost its shine, it has dried suffi­ciently to be removed from the mold.Set aside the ceramic drinking glass you have cast to dry thoroughly before finishing.

You will probably be able to cast several more reproductions in the same mold be­fore it becomes too water-soaked for achieving good results.When you note that the plaster is not absorbing moisture readily, put the mold aside to dry for several days.Then it will be ready to use again.You may hurry this drying proc­ess along by exposing the mold to warm air or an infrared lamp.Never try to bake it dry, however, since this is liable to deaden the plaster, making it incapable of absorbing water.

Casting in a mold of two pieces or more is not very much different than casting in a one-piece mold.Fit the mold together by matching the keys (the male and female hemispheres you formed in your two-piece mold, or the notches you carved in the multi-piece mold).Secure the pieces of the mold tightly together with rubber bands, such as those you cut from old in­ner tubes.If you have no rubber bands on hand, you may tie the pieces together with string.Simply cut notches on top and bot­tom edges of the mold to hold the string in place.Do not allow rubber bands or string to cover the hole into which you will pour the slip.

With a steady, even flow, pour the slip into the funnel-shaped opening, with the slip hitting the side of the opening and running down into the mold.The reason for this is that a hard spot is formed where the slip first comes in contact with the mold.This is caused by a concentration of salts.

Top photo above, pare away the excess clay from sides of the mold.Then smooth bottom surface of the ash tray with metal scraper, always striving to maintain an even thickness throughout clay.For final smoothing use soft rubber kidney, moist sponge.Then, gently remove, dry, glaze, fire.

If this spot were on the surface of the piece, the glaze would not stick to it very well and a dry spot would result after the ware was fired.

Fill the mold to the top.The slip will sink in a few minutes as it settles and the water is absorbed by the plaster.Continue adding more slip until a wall about one-eighth inch thick forms at the top edge of the hole.Turn the mold over and pour out the excess slip.Remove the clay wall from the hole with a knife.

Wait for about twenty minutes to an hour for the clay to shrink away from the mold.Then carefully take the mold apart.

You should have a perfect reproduction of the original model.The slight ridges where the pieces of the mold meet can be scraped away when the piece is firm.This fettling process can be done with a sponge or brush within 15 minutes.It is safer, though, to let the piece become bone-dry before smoothing the mold marks away.Once the piece has dried completely you may fettle it with a knife and sandpaper or steel wool.

Many ceramists save all the dried slip they scrape from the pouring holes or col­lect from pieces which are damaged in the molding process.Such dried slip can be pulverized and used again by mixing it with a batch of regular slip.You should never use more than 10% of the reclaimed slip in any one batch.

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