How to Make Silicone Molds for Resin | A Step by Step Guide
If you’ve ever wondered how to make a resin mold, then you’ve come to the right place!
There are many molds on the market for epoxy resin, however, when we can’t find the mold we want in the market, we have to make a mold by ourselves. Interested in learning how to make these kinds of molds and how to use them? Not to worry. We’ve got you covered! In this step-by-step guide, we would be introducing you to resin casting and showing you just how easily you can make these molds with just four (4) simple steps.
Before we get into the content, however, below is the table of content to help you easily get to whatever part of the guide you need.
1. Which molds are suitable for resin?
2. Important factors for resin molding: The degree of the silicone rubber.
3. Two ways to make a resin mold:
Copy an already existing mold shape.
Shape the new mold from scratch.
4. Preparations for making resin molds.
Things to consider before you begin.
Things you’d need to get started.
5. Step-by-step guide to making silicone molds.
6. How to make a two-part form mold.
Now with that out of the way, let’s get right to it!
1. Which Molds are Suitable for Resin Casting?
Before understanding how to make silicone molds, it is important to first understand which molds are suitable for us to use in resin art? You know, not all molds are very suitable for pouring resin. Silicone mold is the best mold for resin and epoxy resin casting. Because of their softness, they are very flexible when demolding the craft, they last longer than most other molds, and now you can easily customize the mold you want.
With that said, there are other molds you could also use to cast resins, including:
- One-piece block molds
- Plastic molds
- Urethane molds
- Latex molds
- Polyester molds
2. Important Factors for Resin Molding: The Degree of the Silicone Rubber
When creating silicone molds, whether as a DIY project or industrially, the most important factor that determines how well the mold would turn out is the degree of the silicone rubber used.
While silicone is popularly known for being flexible and even elastic, the degree to which it displays these characteristics vary. Depending on the degree of the silicone rubber used, the produced mold could end up as a hard and tough mold, a brittle one, or a flexible and elastic mold.
The degree of silicone rubber is often expressed as “degree of hardness” and is often measured in Shore. As a rule, the higher the Shore, the higher the hardness and the lower the elasticity of the silicone. Based on this measurement, below is a rough classification of silicone rubbers:
- Silicone Rubbers with Shore between 0 and 20: Soft silicone with high flexibility but low thermal and mechanical stability.
- Silicone Rubbers with Shore between 20 and 40: Medium grade silicone with moderate stability and medium flexibility and elasticity.
- Silicone Rubbers with Shore between 40 and 80: Hard silicone with limited elasticity and flexibility. Those with higher shore often end up being slightly brittle though.
The kind of silicone you should use should depend on what sort of mold you are looking to create and what you would be using your mold for. Not sure which degree of hardness is best suited for your project? Get in touch with a more experienced professional.
3. Two Ways to Create Your Resin Mold
There are generally two ways to create a resin mold using silicone. These include:
3.1 Copy an Already Existing Mold Shape
In this process, you would be creating your silicone mold using an already existing mold shape as a template. This method is perfect for creating duplicate articles/items.
3.2 Shape the New Mold from Scratch
In this process, you create the new mold without using a template i.e entirely from scratch. This is perfect for creating items with custom shapes.
4. Preparations for Making Resin Molds
Regardless of the method of creating silicone molds you choose (with or without templates), some preparations need to be made to get started. They include taking into consideration a number of factors as well as preparing the materials to be used.
4.1 Things to Consider Before You Begin
Before you begin thinking of creating your silicone mold, ask yourself the following questions:
- How big is the template/blank or the item I am looking to make?
- What does the surface of the template/blank or the item I am looking to make look like? Is it smooth or does it have ornaments, indentations, or markings?
Your answers to these questions would determine the degree of silicone you would use as well as how much of it would be required.
4.2 Things You’d Need to Get Started
After taking into consideration the questions asked above, it’s time to get your supplies ready for molding. Below are the top supplies you‘d need:
Easy to use, non-toxic, affordable, and highly effective, this silicone mold-making kit is made from top-quality silicone material that is non-toxic, doesn’t bubble, and has been tested and trusted to be safe for home use. The kit comes with two components that use a simple 1:1 mixing ratio by weight to create a fast curing Shore A10 silicone material that forms to be soft and smooth after curing. Add to that the number of other tools that come with these components including the mixing cups, mixing sticks, and disposable gloves, and you have one silicone mold-making kit you can bank on to get the job done.
- B. Scale
Since your mixing is to be done by weight, you would want to have a scale to take the weight. A digital scale is your best bet for this since these sales are easy to use and have appreciable accuracy.
- C. Hot Melt Glue Gun
This would be used for creating the frame for the mold along with the MDF board set.
- D. MDF Board Set
This would be used for creating the frame for the mold along with the hot melt glue gun.
- E. Release Agent
To spray your frame with so your silicone mold can be removed easily.
- F. Template
If you would be using a template then your resin casting, then you would need to have your template ready as well.
- G. Knife
For trimming away the excesses after removing the mold from the frame.
Now that you have all the necessary supplies ready, it’s time to get to the actual molding phase.
5. Step-by-Step Guide to Making Silicone Molds
Start with the Frame
First, you start with creating the frame or the molding house. This is what your silicone mold would be formed in.
To do this, use the MDF board set as your base material as well as the walls that would frame your mold. Remember that your frame must be built to be the right size for your mold. Once you have surrounded the base material with the four walls, use the hot melt glue gun to glue the walls to the base.
While other materials apart from the MDF board can be used to create the frame, not every material is a good choice for creating the frame. For a material to be a good choice for making a frame for your mold, it must have a smooth surface so that the silicone mold can be easily removed after forming, without damaging the mold. Practically any material with a smooth surface can be used for the frame, EXCEPT glass.
If you would be using a material other than MDF board to create the frame, the frame should be properly treated with release agent, so as to aid with the easy removal of the silicone mold after it is formed.
Remember to make sure that your walls are about ten millimeters taller than your blank/template (start measuring from the base material) and that the walls are properly glued together and to the base material.
Mix the Silicone Formula
Next, it’s time to mix your silicone.
Weigh the required amount of each component of the JDiction Silicone Mold-making Kit in a 1:1 ratio. Mix the two components using the mixing cups and sticks that come with the package. Also, remember to use the disposable gloves provided before mixing.
Mix gently to prevent the formation of any bubbles. If you notice any forming, knock the mixing cup against the tabletop to loosen those bubbles. Make sure to wait a few
It is also advisable to mix the components in several small portions especially when the amount of silicone required is large. Since silicone is rather viscous, stirring one very large amount would be almost impossible.
Pour in the Silicone
Place the blank or template in the frame with the part to be cast pointing upwards. Pour the silicone over the blank/template slowly, making sure that the item is completely covered by the silicone and that all the details of the item are captured. Once that is done, fill out the rest of the mold frame with the rest of the silicone with about five millimeters of silicone covering the item. Once this is done, carefully tap the walls of your frame (all four sides) to release every trapped bubble. Finally, leave the mold to harden.
Remove the Finished Casting Mold
While the JDiction Silicone Mold-making Kit is well-known to have a quick curing time, the curing time for any molding process would generally depend on how much silicone was used. This would often take between less than an hour and 24 hours. To determine whether your mold is completely cured or not, gently press your finger to the top of the mold. If you notice that the mass has hardened, it is then time to remove the mold.
6. How to Make a Two-Part Form Mold
It is important to note that the procedure explained above explains how to create a one-part form mold. For a two-part form mold, a different approach is used.
In addition to the supplies already mentioned for the one-part form mold, for a two-part form mold for resin casting, you would also need some modeling clay and Vaseline.
To create a two-part mold, fill the frame halfway with the modeling clay and smoothen the surface. Next, press half of the blank/template into the clay then fill the rest of the frame as you would do with one-part form molding. Once this is done and the mold has hardened, it is removed and placed back into the frame. Finally, the blank/template is then placed back into the half-mold previously cast and then new silicone is poured to fill up the frame.
To make sure the two silicone mold halves don’t fuse into one, the surface of the hardened silicone is covered with Vaseline before the liquid silicone is poured onto it. Once this is done, the second half is also allowed to harden before that too is removed.
So there you have it ─ how to create silicone molds for resin casting in just four easy steps. Follow these steps and you too can create a beautiful mold, even on your first try. And the best part of it? It wouldn’t even cost you much!