Using modeling clay to create a single-use mold for both the roughly-hewn edges of the stone and the engraved rune will make each hearthstone unique. Because modeling clay is so flexible, there is no worry about undercuts in the unmolding process.
Step 1: Supplies
- Modeling clay (NOT Play-doh)* - white or grey are best; colored clays may transfer color to the plaster
- Plaster of Paris
- About 6" of copper wire**
- A piece of clear, smooth plastic - large zip top bag or plastic from a product package
- Paperboard scrap, lumber, cookie sheet or similar for a work surface - must be flat
- A variety of tools for shaping plaster: a craft knife and sandpaper; plastic or wooden clay tools if you have them
- Paper or plastic container for mixing plaster, at least 3-4 cups volume
- Popsicle stick or other implement for mixing plaster
- Hearthstone template - this is about 3½" X 4½" but I have also included the picture file so you can scale it up or down if needed. If scaling, please remember to scale the sizes and amounts of supplies accordingly.
- Acrylic craft paints, etc. for finishing - this part is up to you (see final step for ideas)
**I used copper because it won't rust. Aluminum will also work. Select wire that can hold the weight of the finished product which is a little less than a pound.