Construction of the Frame
The first important thing is to build the frame of the molds. It is crucial to create a tight barrier that prevents resin from leaking through. Use wood or something smooth, no hard material such as glass, as your base plate. Silicone rubber does not repel glass, so removing it can be a real pain. It is therefore also a good idea to use smooth wood to the base plate.
The base plate is surrounded by four smooth sidewalls that can be built out of wood or MDF boards. The wall height should be ten millimeters higher than the object you choose. Seal all the joints of your mold as best you can with modeling clay. Make sure to get into every nook and cranny, smoothing out any imperfections for it to work properly. Using a cotton swab or toothpick, smooth the joints.
Make sure the front of your object in the frame is facing up and that you can use hot glue or strong double-sided adhesive tape to fix it to the floor. It's important not to let the object slip when pouring the silicone mass.
Mixing the Silicone
First, the amount of silicone is weighed. Then it's mixed in a ratio of 1:1 with both components being thoroughly blended together. Utilize the plastic cup and also the wooden rod for this objective. Take care not to waste a lot of silicone. You can establish the total required by simply calculating the quantity or roughly using a measuring rod.
Mixing small portions is far more manageable than mixing large ones. In addition, the silicone will not clump, and it's easier to stir, which makes preparing multiple cups a breeze!
To get the best possible results, you should make sure that your silicone is mixed correctly. First, stir it in a cup and gently tap on the bottom of the cups before waiting for a few minutes. Finally, pour evenly into the frame!
Pour in the Silicone
If you're using wood for your frame, be sure to apply a release agent before pouring in the silicone. Alternatively, you can also coat it with oil but beware: not all oils are compatible with silicon and may attack its surface.
After the frame is sprayed or oiled, silicone mass is poured over it. To duplicate an object with a smooth surface that only has large surfaces, pouring this material can be relatively simple- pour from a large height. Ensure that the entire object is surrounded by silicone.
The process of filling in the blank can be tricky, especially if it has many edges or corners. In this case, pour the thin stream of silicone first and then pour the rest. This procedure ensures that all the important details are seen in the illustration.
Keep going until you are about 5 millimeters from the edge of the blank. When you're done filling your frame with silicone, tap gently on each side of the framing to release any bubbles that might be trapped in the silicone.
Remove the finished casting Mold
When the silicone mold is finished depends on its size and the material. Silicone molds can take only one hour to harden, some up to a day. To see if the process is complete, press into it with a finger. Now take off the mold from the frame. In case you've greased it well beforehand, it is going to work by itself. You can still straighten the edge using a carpet knife, scalpel, or scissors.
The silicone mold can be cleaned with talcum powder after each use. What the powder does is keeps the silicone soft and helps it keep its shape.