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How to Make Silicone Molds for Concrete: A DIY Tutorial

Learn how to make your own silicone molds for concrete with this comprehensive DIY tutorial. Creating custom molds allows you to add a personal touch to your concrete projects at home. Follow the step-by-step instructions below to create high-quality silicone molds for all your concrete molding needs. Click here if you need Advanced concreting techniques for superior and long-lasting results. Enhance your concrete know-how with this comprehensive guide on How to Do Exposed Aggregate Concrete Driveway: Techniques and Design. Discover valuable insights into techniques and design considerations for creating an impressive exposed aggregate concrete driveway, perfect for your upcoming project.

Key Takeaways:

  • Homemade silicone molds offer a personalized touch to your concrete projects.
  • Creating custom molds allows you to capture intricate details and create unique designs.
  • Use pure silicone caulking and cornstarch to make the molding compound.
  • Applying an even layer of the compound around the master form helps capture all the details.
  • Creating seams in the mold facilitates easy removal of the master form.
  • Follow proper curing and setting times for the concrete to ensure successful results.
  • Consider latex molds for more complex or intricate sculptures.

Materials Required for Making Silicone Molds

To make high-quality silicone molds for concrete, the following materials are needed:

  • Pure silicone caulking (ensure it isn’t latex)
  • Corn starch
  • Rubber/latex gloves
  • Non-precious bowl
  • Vaseline (as a mold release)
  • A “critter” or object to use as the master form

These materials are essential for achieving optimal results and ensuring the durability and flexibility of the silicone molds.

When selecting the silicone caulking, it is crucial to choose a pure silicone formula rather than latex-based caulking. This ensures that the mold will have the necessary strength and stability to withstand the weight of the concrete. Corn starch is added to the mold-making compound to increase its pliability and make it easier to work with. Rubber or latex gloves protect your hands from direct contact with the materials and help maintain hygiene throughout the process.

A non-precious bowl is recommended for mixing the silicone caulking and corn starch to avoid any damage or staining to valuable kitchenware. Vaseline serves as an effective mold release agent, preventing the silicone from sticking to the master form. Lastly, a “critter” or object is required to serve as the master form—the item from which the silicone mold will be created.

By gathering these materials, you will be well-equipped to embark on the exciting process of making silicone molds for your concrete projects.

Preparing the Molding Compound

Follow these steps to prepare the molding compound for making silicone molds:

  1. In a non-precious bowl, put a pile of cornstarch at the bottom.
  2. Cut the end of the silicone caulking tube and poke a hole in the tube.
  3. Squeeze the silicone into the bowl, using about half a tube.
  4. Sprinkle more cornstarch on top and stir it with a disposable paint stick.
  5. Once the mixture becomes pliable, use your fingers covered in cornstarch to knead it into a modeling clay-like consistency.
Key MaterialsAmount
Silicone CaulkingHalf a tube

Vital Steps in Preparing the Molding Compound

  1. Prepare Work Surface: Use a non-precious bowl to prevent damage.
  2. Opening the Caulking Tube: Cut the end of the silicone caulking tube and create a small hole.
  3. Squeeze the Silicone: Squeeze out silicone from the tube, using approximately half a tube.
  4. Add Cornstarch: Sprinkle cornstarch on top of the silicone and stir with a disposable paint stick.
  5. Knead the Mixture: Use your fingers covered in cornstarch to knead the mixture until it reaches a modeling clay-like consistency.

Applying the Molding Compound to the Master Form

Silicone Mold for Concrete

Once you have prepared the molding compound, it’s time to apply it to the master form. Here are the steps to follow:

  1. Flatten the compound and force it to wrap around the shape of the master form. Make sure to cover the entire form evenly.
  2. Ensure an even layer of the compound around the entire form with a thickness of about 1/8″ to 1/4″. This will ensure a sturdy and durable mold.
  3. Leave the bottom of the mold empty to serve as the pouring opening for your concrete.
  4. Press the compound against the form, making sure to capture all the intricate details of the master form.
  5. Allow the compound to dry and stiffen for at least a day. This will ensure that it sets properly and becomes strong enough to hold the concrete.

To visualize the process, refer to the image below:

Creating Seams for Opening and Closing the Mold

Silicone Mold for Concrete

To remove the master form from the silicone mold, follow these steps to create seams for opening and closing the mold:

  1. Cut the mold down the middle and also up the bottom, under the tail.
  2. This will create seams that allow the form to be pulled out of the mold.
  3. The silicone/cornstarch mix becomes stiff but still has some flexibility to hold its shape.

Creating seams in the mold helps in the easy removal of the master form, ensuring a successful mold-making process. The flexibility of the silicone/cornstarch mix allows the mold to retain its shape while providing enough give for the removal of the master form.

Next, we will explore the process of casting concrete in the silicone mold to create your desired concrete piece.

Creating Seams for Opening and Closing the Mold
Cut the moldDivide the mold into two halves along the middle and cut up from the bottom under the tail.
Create seamsThese cuts will create seams that allow easy removal of the master form from the mold.
Maintain flexibilityThe silicone/cornstarch mix remains stiff but still has the flexibility to hold its shape.

Casting Concrete in the Silicone Mold

Now that you have created your silicone mold, it’s time to cast the concrete and bring your project to life! Follow these steps to ensure a successful casting:

  1. Mix the concrete according to the instructions on the bag, making it slightly more watery than usual for easier pouring.
  2. Tap and vibrate the mold to remove any air bubbles and ensure that the concrete fills all the intricate details.
  3. Allow the concrete to cure and set for the recommended timeframe. This could take anywhere from a few hours to a few days, depending on the type of concrete used.
  4. Once the concrete has hardened, remove any plastic or mold material from the outside of the mold.
  5. Carefully remove the concrete copy from inside the silicone mold. You may need to make small cuts in the silicone to free the object without damaging it.

Create beautiful and durable concrete objects using your homemade silicone molds. Unleash your creativity and explore endless design possibilities.

Tips for Successful Mold Making

Creating high-quality silicone molds for concrete requires careful attention to detail and proper technique. To ensure successful mold making, follow these essential tips:

  1. Choose a simple master form: Select a master form with minimal undercuts and intricate details. This will make it easier to release the master form from the mold without any complications.
  2. Use vaseline as a mold release: Prior to applying the molding compound, coat the master form with a thin layer of vaseline. This will prevent the mold from sticking to the form, making it easier to remove once the mold is dry.
  3. Apply an even layer of the molding compound: Ensure that the molding compound is evenly and uniformly applied around the master form. This will help capture all the intricate details and ensure a high-quality mold.
  4. Create seams in the mold: To facilitate the removal of the master form from the mold, create seams in the mold. These seams will serve as openings that allow you to easily release the master form without damaging the mold.
  5. Follow proper curing and setting times: Once you have cast the concrete in the mold, make sure to follow the recommended curing and setting times. This will ensure that the concrete cures properly and achieves its desired strength.

By following these tips, you’ll be well on your way to creating successful silicone molds for your concrete projects.

Potential Alternatives and Additional Resources

If you have a more complex or intricate original sculpture, you may also consider making a latex mold, which offers more stretchiness compared to silicone molds. Latex molds are particularly useful for capturing fine details and intricate designs. However, keep in mind that latex molds may require additional steps and materials for creating and curing.

For further guidance and inspiration, there are numerous videos and articles available online that can help you in creating custom concrete molds. These resources provide step-by-step instructions, tips, and techniques to enhance your mold making skills and explore new possibilities. Whether you’re looking for specific tutorials or seeking inspiration for unique mold designs, these resources offer a wealth of knowledge and expertise.

“Making molds opens up new avenues toward infinite artistic possibilities.”

– Concrete Artisan Magazine

Explore the following websites and channels for additional resources:


  • The Concrete Countertop Institute – A comprehensive resource for professionals and DIY enthusiasts, offering tutorials, guides, and support for concrete mold making.
  • DIY Creators – A popular DIY channel with a focus on concrete crafts. Their website provides detailed instructions, project ideas, and tips for creating homemade silicone molds.
  • Concrete Exchange – An online community for concrete enthusiasts, featuring tutorials, forums, and galleries for inspiration and learning.

YouTube Channels:

  • NightHawkInLight – This channel specializes in concrete projects and provides detailed tutorials on DIY concrete mold making.
  • Savage Brick Sports – Known for their concrete sports-related creations, this channel offers insights into unique concrete mold designs and applications.
  • The Concrete Kingdom – A channel dedicated to all things concrete, showcasing various mold making techniques and project ideas.

By exploring these resources, you can expand your knowledge and skills in silicone mold making and concrete crafting. Remember, practice makes perfect, so don’t be afraid to experiment and unleash your creativity with homemade molds.


Congratulations on mastering the art of making silicone molds for concrete! With this comprehensive DIY tutorial, you have gained the knowledge and skills to create personalized molds that will bring your concrete projects to life. By following the step-by-step instructions and implementing the tips shared in this guide, you will be able to produce high-quality homemade silicone molds for all your concrete molding needs.

Get ready to unleash your creativity and experience the satisfaction of crafting custom pieces for your home. Whether you’re making stunning decorative objects or functional items, the possibilities are endless with your newfound mold-making expertise. With each project, you can add a personal touch and create unique designs that reflect your style.

Remember, the key to successful silicone mold making lies in choosing a simple master form, applying an even layer of the molding compound, and creating seams for easy removal. Take your time, follow the instructions diligently, and enjoy the journey of transforming your ideas into tangible concrete creations.

If you ever need professional concrete services, don’t hesitate to contact Toowoomba Concreters at (07) 4520 1314. Their team of experts will be happy to assist you with any concrete-related projects or queries you may have. Now go forth and let your imagination run wild as you bring your concrete molding ideas to life!


What materials do I need to make silicone molds for concrete?

You will need pure silicone caulking, corn starch, rubber/latex gloves, a non-precious bowl, and Vaseline as a mold release.

How do I prepare the molding compound for making silicone molds?

In a non-precious bowl, mix cornstarch with silicone caulking to create a modeling clay-like consistency.

How do I apply the molding compound to the master form?

Flatten the compound and wrap it around the master form, ensuring an even layer and capturing all the details.

How do I create seams for opening and closing the mold?

Cut the mold down the middle and create seams that allow the form to be pulled out of the mold.

How do I cast concrete in the silicone mold?

Mix the concrete, tap and vibrate the mold to remove air bubbles, and allow the concrete to cure and set before removing from the mold.

What are some tips for successful mold making?

Choose a simple master form, use Vaseline as a mold release, apply an even layer of molding compound, and follow proper curing times for the concrete.

Are there any alternatives or additional resources for mold making?

If you have a complex sculpture, latex molds offer more stretchiness. You can also find videos and articles online for further guidance and inspiration.

What can I create with silicone molds for concrete?

With homemade silicone molds, you can create personalized concrete pieces for various projects, adding a personal touch to your home.

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