How do you use 3D printed molds to make bath bombs?

by Annaliza Muscat February 08, 2023

You can now also use 3D printed molds to make bath bombs. The molds can be used to shape the bath bomb mixture into the desired form, and then removed once the bath bomb has hardened. 3D printing technology can be used to create custom molds in a variety of shapes and sizes, which can make the process of making bath bombs more affordable, accessible, efficient and versatile.

How to get 3D printed molds

There are three ways to get your hands on 3D printed molds. You can purchase the 3D printed molds from fellow makers, or you can purchase the digital file and print the bath bomb mold yourself. If you have your own 3D printer, it is much more feasible to print your own bath bomb molds, but if you don't have your own 3D printer and don't have access to buy the printed molds, you can purchase the digital file use a 3D printing service.

Benefits

There are several benefits of using 3D printed bath bomb molds:

Custom shapes and sizes: 3D printed molds allow you to create custom shapes and sizes for your bath bombs, making them unique and personal. You can design your own molds or have a designer make one for you.
Consistency: Using a mold ensures consistent size and shape for each bath bomb, making them easier to package and sell.
Repeatability: You can make multiple bath bombs that are exactly the same, allowing for consistency in both appearance and performance.
Speed: 3D printed bath bomb molds can be produced quickly, allowing you to make multiple bath bombs in a short amount of time.
Durability: 3D printed bath bomb molds are made from durable material and can last a long time with proper care, making them a cost-effective investment.
Versatility: 3D printing technology allows for the creation of intricate designs and shapes, making it possible to create bath bombs in various shapes, colors, and sizes.
Eco-friendly: 3D printing technology is becoming increasingly eco-friendly, making it a sustainable option for producing bath bomb molds.
Affordable: with an initial small investment in a 3D printer, you will have access to print all the bath bomb molds that your little heart desires. 3D printers have come a long way and have become very affordable. You will save on shipping costs and get the mold at raw material cost by producing it in-house.
Accessible: when you 3D print your own bath bomb molds, you get access to much more designs.

Overall, using 3D printed bath bomb molds can make the process of creating bath bombs more efficient, consistent, and fun.

Some things to consider

If you are considering printing your own bath bomb molds, here are some things that you should consider:

Cost: 3D printing technology can be expensive, and the cost of the 3D printer and materials can be a barrier for some people. If you are new to this technology, start with a small investment to begin your learning experience. The technology of 3D printers have come a long way and will continue to do so, and in the process it has become much more widely affordable and accessible.
Accessibility: Not everyone has access to a 3D printer or the skills to use it, which can discourage some people to print their own bath bomb molds. This being said, if you are interested in starting to print your own bath bomb molds, you will find various free resources online which will help you start your learning journey. There are various online groups and communities surrounding 3D printing. Start by joining a couple of groups and you will find that everyone is always ready to help out each other.
Complexity: The process of designing a 3D mold can be complex and requires technical skills and knowledge. For this reason, most people choose to buy readily available designs to print instead of designing the molds from scratch.
Time-consuming: 3D printing can take a long time, especially for larger or more complex molds, and requires patience and attention to detail.
Maintenance: 3D printers require regular maintenance and cleaning to keep them in good working order.

How do I use 3D printed bath bomb molds?

Here is a general process for using 3D printed molds to make bath bombs:

Prepare the bath bomb mixture.
Fill the mold: Spoon the bath bomb mixture into the 3D printed mold, pressing it firmly into the mold to create an even layer.
Remove any air bubbles: Tap the mold gently on a flat surface to remove any air bubbles that may have formed in the mixture.
Close the mold: Close the pieces of the mold together, making sure that they are securely fastened.
Allow the bath bomb to dry: Leave the mold in a cool, dry place for several hours or overnight, until the bath bomb has hardened and fully dried.
Remove the bath bomb from the mold: Carefully open the mold and remove the bath bomb. You may need to gently tap the mold to release the bath bomb.
Package the bath bomb: Wrap the bath bomb in plastic wrap or place it in a container to protect it until you are ready to use it.

Note: The exact process may vary depending on the specific type of 3D printed mold and bath bomb recipe that you are using.

Bath Bomb Recipe

There is no one "best" recipe for using 3D printed molds, as the ideal recipe will depend on your specific needs and preferences. However, a basic bath bomb recipe that is well-suited for 3D printed molds typically includes the following ingredients:

Baking soda: 2 cups
Citric acid: 1 cup
Epsom salts: 1/2 cup
Cornstarch: 1/2 cup
Coconut oil: 1/4 cup
Essential oils or fragrance: a few drops
Natural Food coloring (optional): a few drops

To make the bath bomb mixture, simply mix all of the dry ingredients together in a large bowl. Then, slowly add the coconut oil, essential oils, and food coloring, mixing until the mixture is just moist enough to hold its shape when pressed into a mold. Fill the 3D printed mold with the mixture and press it firmly into place, then leave it to dry for several hours or overnight before removing the bath bomb from the mold.

Note: This is just one basic recipe and can be adjusted according to your needs and preferences. You can add or subtract ingredients, adjust the ratios, or add other embellishments, such as flower petals or glitter, to create a unique bath bomb.

You may need to adjust the quantity of ingredients depending on the size and shape of the mold. The key is to have enough of the bath bomb mixture to fill the mold completely and ensure that the mixture is pressed in firmly. If you are using a smaller mold, you may need to adjust the recipe by reducing the amount of ingredients. Conversely, if you are using a larger mold, you may need to increase the quantity of ingredients to ensure that the mold is filled completely.

It is also important to consider the shape and design of the mold. Some molds may have intricate details or shapes that require a firmer mixture, while others may have larger, more open spaces that require a softer mixture. You may need to experiment with the recipe to find the right consistency for your specific mold.

If you need to remove the bath bomb from the mold right away and cannot wait for it to dry completely, you may need to make some adjustments to the recipe to ensure that the bath bomb holds its shape. Here are some adjustments you can try:

Use a binding agent: Adding a binding agent such as beeswax, glycerin, or cornstarch to the bath bomb mixture can help it hold its shape better.
Increase the amount of bicarbonate of soda: Bicarbonate of soda is a key ingredient in bath bombs that helps to create fizziness when it reacts with the citric acid. Increasing the amount of bicarbonate of soda in the mixture can help the bath bomb hold its shape better.
Use a harder oil: Substituting a harder oil such as coconut oil for a softer oil, such as olive oil, can help the bath bomb hold its shape better.
Chill the mixture: Putting the bath bomb mixture into the fridge or freezer for a short period of time can help it firm up and hold its shape better when removed from the mold.

These are just a few adjustments you can make to help the bath bomb hold its shape better when removed from the mold. However, it's important to note that each recipe is unique, and you may need to experiment with different adjustments to find the one that works best for you.

Tips for demolding

Here are some tips and tricks for removing bath bombs from a 3D printed mold:

Loosen the edges: Before attempting to remove the bath bomb from the mold, gently tap the sides of the mold using a metal spoon or ruler. This will help to break the suction and make it easier to remove the bath bomb.
Use a release agent: A release agent, such as coconut oil or cooking spray, can help to prevent the bath bomb from sticking to the mold. Simply apply a thin layer of the release agent to the inside of the mold before adding the bath bomb mixture.
Warm the mold: If the bath bomb is still difficult to remove from the mold, try warming the mold with a hair dryer set on low heat. The heat can help to soften the bath bomb and make it easier to remove.
Let it dry completely: If the bath bomb is still not releasing from the mold, it may be that it has not fully dried and hardened. Try leaving the mold in a cool, dry place for a few more hours or overnight and then try removing the bath bomb again.
Be gentle: When removing the bath bomb from the mold, be gentle to avoid cracking or breaking the bath bomb. If the bath bomb does crack or break, you can still use it by breaking it into smaller pieces and using it in smaller portions.
Store the bath bombs properly: Once you have removed the bath bomb from the mold, store it in a cool, dry place to prevent it from melting or losing its shape. Wrap the bath bomb in plastic wrap or place it in a container to protect it until you are ready to use it.

What can I do if the bath bomb breaks when removing it out of the mold?

If your bath bomb breaks when you take it out of the mold, don't worry, you can still use it! Here are a few things you can do:

Use it as is: If the broken pieces are still relatively large, you can use the bath bomb as is by placing the pieces in the bathtub and letting them dissolve.
Grind it into smaller pieces: If the broken pieces are small, you can grind them into finer pieces using a food processor or coffee grinder. Then, you can use the ground bath bomb as a bath soak or add it to a sachet for a more convenient way to use it.
Re-mold it: If you have enough broken pieces, you can try re-molding the bath bomb. Simply mix together a small amount of the bath bomb mixture and press it together with the broken pieces. Then, let the new bath bomb dry and harden.
Use it as a molding base: You can also use the broken pieces as a base for a new bath bomb. Simply mix together the bath bomb mixture, press it into the broken pieces, and let it dry and harden.

Remember, bath bombs are typically a DIY product and some breakage is normal, especially when using a new mold or trying a new recipe. Don't be discouraged, just try again and adjust your methods as needed!

Do I need to adjust my recipe if the bath bomb keeps breaking?

It depends on the reason for the breakage. Here are a few reasons why your bath bomb may break and what you can do to adjust the recipe:

Over-mixing: If you over-mix the bath bomb mixture, it can become too wet and break when you try to remove it from the mold. To avoid this, make sure to mix the ingredients until just combined and avoid over-mixing.
Improper ratio of dry to wet ingredients: If the ratio of dry to wet ingredients is off, the bath bomb may become too dry and crumbly or too wet and break when you try to remove it from the mold. To adjust the ratio, you may need to add more or less of either the dry or wet ingredients to the mixture.
Using a different mold: If you are using a new mold, the size and shape may be different from your previous mold. This could result in a different ratio of dry to wet ingredients, which can cause breakage. To adjust for this, you may need to add more or less of either the dry or wet ingredients to the mixture.
Exposure to moisture or humidity: If your bath bomb has been exposed to moisture or humidity, it can become too soft and break when you try to remove it from the mold. To avoid this, store the bath bombs in a cool, dry place and wrap them in plastic wrap or a container until you are ready to use them.

If your bath bomb is breaking frequently, it may be helpful to make small adjustments to the recipe and method to see what works best. You can also try using a different mold or using a release agent, such as coconut oil or cooking spray, to help prevent the bath bomb from sticking to the mold.

What can I do if the bath bomb mixture gets stuck in the mold?

If the mixture gets stuck in the mold, there are a few things you can try to get it out:

Use a release agent: Before filling the mold, lightly coat it with a release agent, such as coconut oil or cooking spray. This will help prevent the mixture from sticking to the mold.
Tap the mold: Gently tap the mold on a hard surface to help loosen the mixture.
Use a tool: If necessary, use a tool, such as a butter knife or plastic spoon, to gently pry the mixture out of the mold.

If the mixture is still stuck in the mold, you may need to make small adjustments to the recipe, such as adding more oil or reducing the amount of water. Additionally, you can try using a different mold or experimenting with different release agents to see what works best for you.

Printing your own bath bomb molds will gain you access to more affordable bath bomb molds along with a larger variety of designs. If you want to print your own bath bomb molds or you would like to print bath bomb molds to sell through your small business, here is where you can purchase the files.