Making quick-drying molds of ceramic tiles

Making molds of my ceramic tiles enables me to produce tiles in quantity. I’m using one bisque-fired mold and three more are drying. That’s the problem…they take so darned long to dry. These molds are made of white clay and they are very durable. At least so far. Several times, I’ve even placed a slab on the floor and stood on the mold to make sure I get a deep impression. I don’t want to push my luck, though. The molds I’ve made are very thick and need controlled drying to prevent warping. While I wait, the molds grow moldy. It’s a sign of good clay, good organic matter. However, it isn’t safe to be around mold, to breathe in the spores. Now and then, as they dry, I quickly rinse them to remove the mold. I’m thinking of spraying them with some type of solution to actually kill the mold, but will have to look into whether that will affect the clay. This site is a good start and it suggests using vinegar. And I’m also considering other forms of molding. If I’d molded these tiles out of a material that dried more quickly, I would have more tiles in my inventory at this point. Time is important, as I became ill and got behind in my studio time. So, I’ve started investigating mold-making. I came across a tremendous site, very comprehensive, called Mold Casting Tips. The site recommends that “when casting molds, Pottery Plaster #1 is best because the particle sizes are small and will capture detail the best.” Given this advice, I looked up a site called Sculpture Supply Canada and found this product: USG No. 1 Pottery Plaster. The product is described as the industry standard, “noted for outstanding performance and long life.” It sounds like this is something that could work well for me and I’m going to look into it. I’ll check to see if our local supply house has it, The Green Barn, in Langley, because I don’t relish having to pay postage on a 50-pound sack of plaster. I did find very specific instructions for working with this product at a U.S. site, The Compleat Sculptor. Info about the plaster includes technical properties, general directions and guidelines on use and storage. Click here to be directed to the page. I must also choose a different material to prevent the clay from sticking to my molds. Thus far, I’ve used cornstarch but don’t really like using it because it seems to accelerate mold growth. I would rather find something inert. I’ve heard my friend Joan say she uses talc and I’ll have to ask her more about that. For now, I’m just happy I’ve found a durable, quick-drying material for making molds, Pottery Plaster # 1.