Below you will find our simplified take on silicone mold making. The idea is to keep things simple, use household items when possible and enjoy the mess along the way. Let's jump in.
You will need the following:
- A Small Item to Cast- make sure it's clean
- Silicone- preferably tin cure like this- Mix Kit
- Mixing Cups- 2 party style drinking cups
- Stir Sticks- popsicle type will do
- Safety Equipment (gloves and mask)
- Parchment Paper
- Glue Gun- preferably a dual temp like this
- Patience- Critical.
- The Item
Choose an object that you want to replicate. Something small, basic and simple. This exercise is just a self test before we get into the advanced mold making projects. It could be a seashell, a figurine, Lego, or even a rock from outside. Make sure that the object is clean and dry before starting the process. Wash it with a dish type soap then dry. Oh, plug in the glue gun and warm it up.
- Prepare the Mold Box
This is the housing of your mold. Usually a basic square or circle and it will contain the silicone as it is poured over your object. Hopefully your object is small, like a playing dice or something of that nature. Cut the cardboard into strips. Go with 1" longer and 1/2" taller than your object. Set your parchment paper down and glue gun the item down so it stands firm to the paper. Next, use the strips of cardboard to form a box around the object. Glue up all edges of the cardboard strips to ensure the silicone does not leak out.
3.Mix your Silicone
Next, prepare the silicone according to the instructions on the package. We suggested a mix that is 1 to 1, meaning equal part A side to B side. Mix the material in the party cup until the color of the silicone is 100% UNIFORM. That means, no swirls of darker colors floating around in your cup.
Apply a release agent to the object and the container to prevent the mold material from sticking. Pour the mold-making material over the object, making sure that it covers the entire surface evenly. Tap the container gently to remove any air bubbles.
4.Pour and Walk Away...Don't Touch It!
I will preface this early on before you pour. Usually, this is where we would de-gas or remove the air bubbles from the silicone using a vacuum chamber, but we will go at this old-school. Pick a corner of the newly formed mold box, get that cup of silicone about 18" above the spot where you will pour and let it flow at the thickness of a guitar string. This will naturally release an air bubbles from the material. KEEP THE POUR IN ONE PLACE. I know it is tempting to go ham and spread the material, but it will flow over your object perfectly. Trust!
The mold-making material will take some time to set, usually 18-24 hours before removing. Follow the recommended time on the package and wait patiently for the mold to harden.
5. Remove the Object from the Mold
Once the silicone has set, carefully remove the cardboard walls and carefully peel the mold up from the parchment paper. Ultimately, you will have a cube of silicone with the bottom of your object left visible. Flex it out or you can use a knife or scissors to cut the mold half way open and remove the object.
Look at what you have done...a MOLD!! This process is done by Pacific Mold Design on a daily basis. To this day, there is nothing more rewarding to us than a successful birth of a mold. You can do it, because we started in this way too.
Now, go cast a few duplicates of your thingamajig!
If you had a rough time or feel like you do not want to do this on your own, we can help. Our Custom Mold Shop is always open for a quote. Find the inquiry page here.