Making the Mold
Glue the tiles to the bottom of your acrylic box, spacing them about a quarter-inch apart. Do not allow any glue to seep out from under the tiles. Use a pre-made box with dimensions that hold your tiles without leaving a lot of excess space. Since this example uses six 1-inch tiles, your box should measure approximately 7 inches by 7 inches. You might use a tackle or bead box with removable dividers.
Fill the mold box with rice. This helps you figure the volume of your box so you do not waste silicone. Pour the rice from the box into a measuring cup to find the volume.
Pour equal parts of side A and side B of Polyaddition silicone into separate containers. Combine the two parts into one larger measuring cup and stir for two minutes.
Pour the silicone into the mold box. The silicone should completely cover the tops of the tile. Wait at least two hours before removing the mold.
Casting the Tiles
Heat up the mold in a microwave until it is warm to the touch. This step generates part of the heat the resin needs to cure properly.
Mix polyester resin with a hardener in a clean cup. This step also helps the resin cure properly. Hardener mixes with the resin, creating heat that hardens the resin. Add 15 drops of hardener for each ounce of resin and mix with a stir stick.
Add dye to the resin. You can divide the mixture to make several colors. For instance, if you want three different colors, use three containers of resin. Add a few drops of dye to the resin and stir.
Pour the resin into the mold. To ensure a flat surface for your tiles, place a sheet of mylar over the resin as it dries. Lay the film slowly on the mold, starting in one corner and working your way across. This way, you do not get air bubbles under the film.
Tap the backs of the tiles to check that the resin has completely hardened. This may take several hours. When the resin is fully cured, peel the mylar from the back and remove the tiles. Resin may have seeped out around the mold during curing, creating a thin layer of hardened resin around the tiles. Break this away from the tiles, creating clean edges.
Things You Will Need
- Six 1-inch mosaic tiles
- Acrylic box
- 5mm mylar film
- Glue gun
- Side A Polyaddition Silicone
- Side B Polyaddition Silicone
- Plastic stir stick
- Plastic measuring cups
- Polyester resin
- Resin dye
- This example used small mosaic tiles as the basis for a mold. You can use any type or size of tile you wish. Keep in mind that larger tiles require larger mold boxes, more resin and curing ratios. Follow the directions on your casting materials to adjust for these differences.