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.
Tag Archives: plaster mold
I’m thinking of making some draped or folded porcelain vessels to replace slipcast flower pots. All but one of my African violets are in the wrong kind of pot. They need two-piece nesting vessels, the outer one glazed, the inner one unglazed. Water is poured into the outer bowl and the moisture leaches through the porous middle pot to the plant roots. I want the vessels to have a somewhat constrained, yet haphazard feel…to combine sculpture with function. I looked at some pieces by artists that are shown online. Some of the techniques used wouldn’t be appropriate for my purposes, but I’d like to use a folded, paddled form, something similar to the piece shown above. An elegant vessel by Mary Rogers, it is called Folded Porcelain Bowl. From Derbyshire, England, Rogers’ work is incredible and I’d like to feature her at some point. Some of her pieces have a marine biological feel, which also appeals to me. Next, I found Carol Barclay, a Rochester, New York artist who drapes porcelain. Drape molds are available commercially at this U.S. art supply store, but you could make your own with plaster, too. Here’s a link for rectangular wooden drape molds from Tucker’s Pottery Supplies online store in Ontario, Canada. Barclay’s “Gathering Bowl” is quite nice. I think I like hers best as sculptural forms only because I can then concentrate on the draping. Finally, some folded porcelain vessels that have a more clean-edged, modern appeal. By Danish designer Karin Blach Nielsen, these delicate pieces called “Snack Bowls” are made from molds made of folded paper. I like the asymmetry. Blech Nielsen creates dinner sets and one-off pieces of porcelain and stoneware. Here’s a link to a serving dish with a filigree pattern.
When I began working in clay at the city art centre, one of the first projects I made was a tile based on the Green Man motif. I’d cast my face for a previous project, so used that mold. Our hillside is covered with English Ivy, so, for greenery, I rolled thin sheets over leaves, then cut them out. I liked the veining that showed. Overall, I really liked the project and how it turned out but, as you can see, it cracked. I later learned that it cracked because the base and face didn’t have the same level of dryness when I attached the two. I thought they were close to the same, but was wrong. The tile was bone dry when fired and came out of the bisque firing okay. However, it tore apart, as shown, when it was glaze fired. The face portion takes a lot of work and is more exposed than the base and I don’t think I can match dryness levels, so the next time I do this, I will only make masks. The results are a bit other worldly and I like that. The clay is white and the glaze is Oribe green.
We cannot display this gallery