How to make your own silicone molds
Making your own silicone molds is very easy once you get the hang of it. You may be looking into this because you like creating your own supplies, you may be in search for a unique mold, or even just for the fun of it.
To start off you will need some basic supplies as follows:
- liquid silicone rubber
- measuring / mixing cups
- weight scale
- stirring tool
- frame and pieces to mold
- glue gun or tape
- knife cutter
The easiest silicone to use is pourable liquid silicone. Look for silicone suitable to use for mold making, and to start off with buy small jars to test the brand and see how it works for you before investing in a larger batch.
Liquid silicone rubber comes in two parts (part A and part B) which you will need to mix together. Brands will vary from one another as to the mixing ratio (e.g. 1:1) and also mixing method (volume vs weight). Make sure to follow the instructions of the brand you are using for best results. If you're required to measure by weight, you will need a weight scale. On the other hand, if you need to measure by volume, cups with volume guide will be very beneficial.
Things to keep in mind before you buy your silicone:
- If you will be using the mold for food, make sure to buy a food safe silicone.
- If you work with UV resin, look for clear silicone. For UV resin to cure, light needs to be able to pass through into the mold.
For measuring cups you can use plastic or glass. Once the silicone has cured, both are easy to clean and re-use. So make use of whatever is handy to you. The same applies for stirring tools. You can use metal, wood or plastic. Then when the silicone has cured you just remove it from your tool and then re-use. Don't use any silicone tools to mix your silicone in or with. Silicone can stick to other silicone, so silicone tools are not ideal in this instance.
Then depending on what you will be molding, you will need some other supplies. If you will be creating your own frame, you can re-use plastic food containers or buy some from a dollar store. You will also need a glue gun or some tape, and a knife cutter to clean the mold as necessary.
Lastly you will need the pieces that you will be creating the mold from. Do not use silicone shapes to take the mold from, since the silicone will bond together. Otherwise, you can use a wide range of items to create your mold from.
For anyone with access to a 3D printer another option is to buy or make files to make your molds with. I make my own designs and create an in-built frame to make silicone molds. This makes the process easier and faster, and once I have the 3D print all I need to to is pour the silicone into it.
Once you gather all of your supplies, start by preparing the pieces that you will be molding into their frames. Stick the pieces into the frame/container with tape or a glue gun. Then measure and mix the silicone as per the brand instructions, and pour the silicone into the prepared containers. Wait for the silicone to cure and take it out from the containers.
For curing time, you will need to refer to the specifications sheet for the silicone brand that you are using. The time range provided will also depend on a temperature range. So keep in mind that if you are working in colder conditions, the curing time will be be longer than that stated. This is an important factor to keep in mind because if the silicone has not cured fully yet, you may tear the mold when removing it from the container.
From the video below you can see how easily the silicone mold comes out from its container. For the first mold, it's a DIY "container". I made it by using a 3D printed circle frame and to make the mold I sealed one side with tape and stuck the resin cabochons on the tape, then poured in the silicone. For all the other molds, they were made with a fully 3D printed design and container.
The next and final step is to clean off the molds as needed using a knife cutter.