Hey guys! This short tutorial of how to make flexible silicone molds was a big source of inspiration to format my website. I hope my descriptions and instructions are clear enough for you, and if not please don’t hesistate to comment below asking for clarification or other questions. Happy mold making, yo!
Clicking on the pictures will direct you to a new page with an enlarged version of my image.
- Measuring Silicone
- Mold Objects
- Preparing the Pour
- Pouring the Silicone
- Curing Process
- Removing the Mold
- Clean Up Edges
What do we need (What I used):
- Liquid silicone (2 pounds Copyflex Liquid Silicone)
- Objects for the mold shape:
- Plastic/glass gems (Clear aquarium stones)
- Oven-bake or sculpting clay (Sculpey)
- Flat bottomed and sided container for mold (Plastic lunch container)
- One or two flat bottomed and sided mixing containers (Old movie popcorn buckets)
- Flat-edged mixing stick (Clean popsicle stick or plastic ruler)
- Measuring scale (Mechanical food/kitchen scale from local drug store)
- Butter knife (Random metal knife from kitchen)
- Optional: Water/containers for measuring sufficient liquid volume needed
- Optional: Calculator
- Optional: Glue + small paint brush for glue application on bottom of mold objects
- Optional: Small scissors or makeup scissors for triming off silicone that creeped under your shape during curing
1) How much liquid silicone will you need?
a. Place objects you wish to make a mold of in the mold container.
b. Fill container with water until the water is at least ¼ inch above the highest point of your objects. This water represents the ounces you need (total) for the silicone.
c. Divide this number by 2 to get the ounces required from both silicone parts, A and B (assuming you are using a 1:1 silicone compound, which makes measurement a hellofalot easier).
a. Your liquid silicone supplier should provide calculations for determining the quantity you need. If none are provided, use the calculation I used to measure for my CopyFlex compounds (found on makeyourownmolds.com/copy-flex).
L” x W” x H” (thickness of mold container) = cm³ (cubic inches) of the liquid silicone that you will need.
b. Multiply this number .70 to find the weight in ounces.
This calculation and measurement step is the hardest part, but don’t worry. Just make sure you have enough silicone and we’ll come back to it after we do stuff with the objects we want to mold.
2) Mold or find the shapes of the object(s) you wish to make a mold of! For my shapes I used oven-bake clay for specific shapes and sizes, and other little gemstones for smaller shapes I used to fill in the space between my bigger shapes.
3) Paint a thin layer of Elmer’s glue to the bottom of each shape to keep it in place and put it in the mold container. The glue helps keep silicone from sliding underneath the object, and make sure to wipe away any glue that squishes out the sides so it doesn’t mess with the mold’s outline.
Preparing the Pour
4) Measure your silicone on an electric or mechanical kitchen scale and mix it together really well in an appropriately sized container. I used a ruler for mixing because it has flat sides and you need flat sides of your mixing utensil in order to make sure you aren’t missing any unmixed compounds on the sides of your container.
5) MIX ‘ER UP REAL GOOD NOW.
Pouring the Silicone
6) Time to pour! Do what the pros call a “stretch pour” by pouring in one spot 12” above the to-be-mold. This way, the air bubbles we created during mixing are eliminated as the silicone stretches while pouring. You will actually see the little air bubbles stretch and break as they fall off the edge of your mixing container.
7) Start your pouring in one corner of the mold box and let the silicone ooze across the surface. Sllloowwwlyyy move across the mold box while stretch pouring on the liquid silicone. Do not pour directly on your object just in case an air bubble gets trapped on your mold object and accidently disfigures the shape of the mold.
8) Wait your liquid silicone supplier’s designated cure time so the mold has time to moldify. CopyFlex cures in four hours, but I preferred to just come back to it the next day. The cure time will depend on the temperature in your workspace and how much you poured, so since my house can be as cold as a meat locker wanted to give my stuff more time. When working with silicone, it is usually preferable that your house is around room temperature.
9) How do you know the silicone is cured? The silicone will not imprint if you touch its surface. My Copyflex mold was not as squishy as I expected but it looked perfect!
Removing the Mold
Don’t rush removing your mold from its container, this is a slow but cool process.
10) Gently pull at the edges of your mold where your silicone meets the plastic container. Pull at the edges all around the container, slowly loosening the top half. Once you’re back where you started, use a slim, flat object like a butter knife to wedge and unstick the mold from each side, use your best judgement to gently pull the silicone sides up.
Make sure you distribute the “unsticking” process equal for all sides of the container. The mold should pop out fairly easily from its plastic container.
11) Congrats you have a mold!
Hopefully you found this tutorial helpful, and it clarifies the process of making a mold with liquid silicone. This was my first time making a mold, and if I forgot to mention anything/you want extra information just let me know! Good luck in your own project you can do it!
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