How to Repair a Silicone Mold

Your silicone mold will inevitably need to be repaired at some point. Whether it has been damaged by a mishap or is just showing its age, several ways are to repair it. In this blog post, we’ll walk you through the most common methods for how to repair a silicone mold.

How to Repair a Silicone Mold

Not all repairs will be successful, so it might be best to replace the mold altogether if the damage is too extensive. When this happens, it’s important to know how to repair them so you can continue using them for all your cooking needs. With that said, let’s get started!

Summary: Silicone molds can be used to create intricate shapes in the art of molding and casting. However, they may need to be repaired if they become damaged or start to show signs of wear. Repairing a silicone mold is possible with the right materials like flexible silicone sealant, acetone, and a toothpick.

First, use an old toothbrush dipped into acetone to clean off any debris from the surface of the mold. Next, patch any holes using flexible silicone sealant, making sure to even out any ridges that have formed.

10 Ways on How to Repair a Silicone Mold

1. Fill in Cracks and Seams:

Silicone has a memory and can be stretched. So, if you stretch it out and allow the silicone to relax, it will snap back into place. So, take two pieces of silicone (of about equal size), stretch them, so they stick together, lay them over the crack or seam, and presto!

2. Fill in Holes:

This method is similar to the above, except you’re filling a hole instead of a crack or seam. Again, you can stretch and stuff as necessary until you get an appropriate result. If it’s still not workable, use some release agent on your end piece and stick it onto the side you’re trying to fix.

3. Put a Piece of Plastic Wrap Over the Hole:

This is an easy and quick way to solve a problem: Cut a piece of plastic wrap just large enough to cover the hole, press it down into place, and use your finger to get it all in there. Then, smooth over with a cotton swab soaked in release agent.

4. Use a Puddle of Silicone:

If a silicone mold has a few large cracks or holes, you can use some release agent on your finger and smooth over the inside of the mold. Then pour in some puddle of silicone (about 1/8″ thick) and carefully spread it around with your gloved hand. Make sure to mix up the direction you’re spreading; otherwise, you’ll have a stripy-looking mold. Allow it to cure and repeat as necessary.

Use Release Agent on Your Finger

5. Scrape Out the Damaged Area:

You can easily repair damaged areas by filling them with release agent and puddle silicone. Experiment to see how deep or wide an area you can safely repair. Use your finger to smooth it down.

6. Use Some Sugru or Filler Putty:

Sugru is a mouldable glue that cures overnight at room temperature. So if you find yourself in need of some emergency mold repair, you can use it to fill in gaps. It’s quite strong when cured, but it can be cut if needed. Filler Putty is similar to Sugru, but it’s cheaper and has a slightly longer curing time.

7. Use Sculptie or Apoxie Sculpt:

Sculpting materials are moldable materials that cure at room temperature over time. They harden once fixed, but can be sanded down if needed. For example, Apoxie Sculpt is stronger than Sculptie, and cured Apoxie is harder than the original material mixed with; however, both can be cut if needed.

8. Make a Plasticine Model:

If you don’t have any mold repair materials, you can sculpt the damaged area with some plasticine clay. Allow it to cure overnight and then very carefully smooth over the outside with your finger dipped in a release agent.

9. Use Polymer Clay:

Polymer clay has a fine surface texture, making it good for repairing mold damage. It cures at room temperature, but it can be messy to work with because of all the static. In addition, you’ll need some release agent on your fingers, and you have to wait at least an hour before you can use the repaired mold.

10. Use Plaster Wrap:

Plaster wrap is a fabric-like material that you cut to shape and then soak in water; it becomes tacky and cures to form a rigid, lightweight plaster cast. You can use it to create a frame for repairing larger damaged areas. It’s quite strong, but you’ll need to reinforce the edge with Apoxie Sculpt or Sculpture.

Use It to Create a Frame

Some Helpful Tips and Suggestions

Some helpful tips and suggestions on how to repair a silicone mold.

  1. Using a rotary tool, you can make your cut very smooth and even.
  2. Make sure to wear safety goggles when cutting the mold – the plastic is sharp!
  3. It may seem like there is not enough time or patience for this project (when in reality it’s an evening’s work at most), but you must be patient when cutting the mold. It is very easy to crack or chip it, which results in ruined pieces.
  4. When remembering the original shape of the part, think of its silhouette. This helps you to imagine the result.
  5. After cutting out a part, use a knife with a serrated edge to rough the edges up and remove any rough spots or pieces of silicone that may have been left behind after your cut. You can also use an x-acto knife for this job, but use it with caution.
  6. If your original part has difficult to remove support material, like armature wire (wire used under the mold while it is still drying), try removing as much of it as you can with an exacto knife or other sharp objects before using the rotary tool for cutting out the piece. The cleaner the cut, the better your final piece will look.

Tips for Keeping Your Resin Silicone Molds in Top Shape

1. When resin curing is complete, take your time removing it from the mold. To remove cured resin from a silicone mold, you can use a hairdryer on the hottest setting or place it in direct sunlight for several minutes to heat up and soften the material enough to release the part.

2. Allow new molds to sit for 24 hours before use. This allows the mold to cure completely and minimizes the possibility of air bubbles or trapped debris on your part.

3. If you notice a bubble or resin residue on the surface of your mold after casting, soak the silicone mold with 90% isopropyl alcohol until it’s fully saturated and most of the bubble is gone. Then it can be reused.

4. If you notice your mold is warped after casting, try soaking it in warm water for 15 minutes or until the initial curve subsides before reusing.

5. To keep your molds working well, always store them flat on a clean water-resistant surface like waxed paper or aluminum foil.

6. Silicone molds will work fine with high-temperature and low-temp resins, but keep in mind that low-temp resin may take longer to cure.

7. Keep the room temperature under 70 degrees Fahrenheit when casting with silicone molds to reduce the shrinkage of your part.

Keep the Room Temperature Under 70 Degrees Fahrenheit

What Causes a Damaged Silicone

Silicone mold making is a popular medium for hobbyists and professionals. Unfortunately, silicone molds are susceptible to damage from environmental factors such as heat and moisture and normal wear and tear. A broken or damaged mold will leave you scrubbing the floor, searching for your mold-making supplies. Fortunately, you can repair a broken mold.

When repairing a silicone mold, it is important to clean and treat the silicone before attempting repairs. This will help prevent further damage to your mold and give your new mold-making material adhesion points which won’t leave bubbles or gaps in the repaired area. Start by shaving off any fractures or chunks of silicone peeling away from the mold.

You Can Check It Out To Fix Resin Mold

Can a Rubber Mold That Has Torn in Production Be Repaired

A rubber mold(or any other type of mold) can be repaired in production. It depends on the damage to the mold, but these repairs are common at even huge factories. Fixing a silicone mold that has torn is more complex but not impossible.

The key to repairing a silicone mold is taking the appropriate steps while still in its liquid state. Once it has been fully cured, some damage is more complex, if not impossible, to repair. Therefore, the first step when repairing a torn or otherwise damaged silicone mold is to cut away the bad section of the mold. This will leave behind an open space in the silicone mold in which to work.

You Can Check It Out to: Repair a Cut Security Camera Wire

Frequently Asked Questions

What Glue Will Stick To Silicone?

There are a few types of glue that will work well on silicone, including cyanoacrylate (CA), methacrylate (MA), and polyvinyl butyral (PVA). All three have similar properties such as being able to adhere to surfaces, resisting water and oil absorption, and lasting for a long time.

It is important to test the glue first before using it on your silicone project. Apply a small amount of the adhesive to one side of the silicone piece and Wait 30 minutes before applying any other pieces so that the adhesive has had enough time to dry completely. Once you’re happy with how it’s working, apply more layers until you reach your desired thickness or finish.

Can You Glue Silicone To Silicone?

While it is possible to glue silicone to silicone, this may not be the best idea. When you glue silicone pieces together, it can create a weak bond that is likely to fail over time. Additionally, the heat and wear and tear associated with daily use could cause these joints to crack or even break. It’s generally recommended that people avoid gluing Silicone together in order to prevent damage or discomfort.

Does Hot Glue Work On Silicone?

it depends on the type of silicone and Hot Glue that you are using. In general, silicone is a difficult material to adhere to, and Hot Glue will not usually stick to it well. If you are using a high-quality Hot Glue and silicone material, then you may be able to achieve a temporary bond. However, if you are using a low-quality Hot Glue or silicone material, then your chances of success are much lower.

Does Epoxy Work On Silicone?

Epoxy is a two-part adhesive that is most commonly used to attach wood to other materials, such as fiberglass. However, it can also be applied directly to silicone surfaces for repairs or modifications.

While many people believe that epoxy will not adhere well to silicone, this isn’t always the case. In fact, some users recommend using an epoxy/silicone combination sealant because it’s more durable and less likely to peel than either one alone.

There are a few things you need to keep in mind when using Epoxy on silicone: first, make sure the surface is clean and free of oil or grease; secondly, use a low-viscosity Epoxy if your goal is just short-term protection; and finally, apply Epoxide sparingly so as not to damage the fragile bond between the two substances. Always start with a small amount and increase only until desired results are achieved.

Make Sure the Surface is Clean


Silicone molds are popular for casting concrete, plaster, and other materials. They offer many advantages over traditional metal or plastic molds, such as flexibility and the ability to create complex shapes. However, if you have ever tried to make a silicone mold, you know that they can be quite fragile.

Popular for Casting Concrete

However, they can also be delicate and require special care when cleaning and repairing. In this article, we have outlined some simple steps you can take on how to repair a silicone mold. Have you ever had to repair a silicone mold? What tips would you add? Let us know in the comments below.

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