Epoxy resin: what it is and how to use it

Among the materials with which we like to work, epoxy resin is certainly the most versatile: it can be used alone or in combination with different materials, it allows you to obtain unique creations that can be customized as desired and offers a wide range of aesthetic effects, from since it is possible to define the degree of transparency and brilliance. Furthermore, the biodegradable and non-toxic variant is already on the market, which respects the environment without losing durability and resistance. This is why epoxy resin is used in both crafts and industry for the production of a multitude of objects such as decorations, furniture, coverings and jewellery.

In this article, we will explore what epoxy resin is, how to use it correctly, and the different types available on the market.

What is Epoxy Resin?

Epoxy resin is a chemical compound made up of two main components: the resin itself and a hardener. When these two elements are mixed, a chemical reaction (polymerization) is triggered which leads to the solidification of the material. Once hardened, the resin becomes a resistant and waterproof material.

Its main features include:

• Mechanical resistance: it is robust and durable. We used it to create trays, placemats and lamps because we are sure that it can support reasonable weights and resist heat well
• Adhesion: Can adhere to a wide range of surfaces. It has embellished many of our wooden objects, such as our hand-carved bamboo cutting board: it was enough to pour it into the engravings to obtain an object out of the ordinary
• Versatility: can be colored, shaped or used as a protective coating. We prefer powders that give a metallic and shiny effect, but there are dyes that do not affect transparency or even fluorescent, marbling, pearlescent and so on and so forth!

How to Use Epoxy Resin

Using epoxy resin requires care and precision. Here are the main steps for working with this material:

1. Preparation of Instruments and Environment

The work area must be well ventilated; alternatively, use a protective mask to avoid inhaling vapors and wear gloves to avoid coming into direct contact with the resin. Protect the surfaces with waxed paper or plastic sheets: in general, once the resin hardens it is quite simple to remove it, but some marks may remain.

Make sure the surface you are working on is not slanted, otherwise the mixture will not distribute evenly. We have an uneven floor, so we use a level and plywood or plexiglass supports to rebalance the position of the mold with which we intend to work.
Choose a surface that you can do without for a couple of days: once the mold is filled you will no longer be able to touch it or move it until the mixture hardens (we'll talk more about this in a moment).

Identify the type of epoxy resin needed for the project you want to create:

• Clear Resin (perfect for art projects, jewelry and furniture coverings)
• UV resin (ideal for small projects such as pendants or details on objects, as it hardens quickly under a UV lamp or sunlight)
• Casting Resin (for castings thicker than 1 cm such as wooden and resin tables or three-dimensional decorative objects)
• Coating Resin (for thin, uniform applications, such as floors, tables or work surfaces)

UV resin is not two-component and follows its own rules. We use it almost exclusively for small touch-ups or decorations, so we will only dedicate brief mentions to it.

 

 

2. Mixing the Resin and Hardener

To calculate how much resin you will need, remember that you will need 1 kg of resin per millimeter of thickness required over an area of ​​1 m2; then, simply multiply the desired thickness (in millimeters) by the surface area (in square meters). Or do like us and rely on an online calculator!

If your creation requires a casting with a thickness greater than 1cm, you will have to proceed in layers: when the two components are mixed they release heat and, if the casting is too abundant, the temperature continues to increase, speeding up the hardening process to the point of creating cracks, shrinkage and yellowing. It's best to pour one layer at a time and wait for it to harden before adding more resin, so prepare only the amount of mixture you need for the first pour.

Once you have calculated the total quantity of resin you need, define the ratio between the two components based on the indications on the bottles, which vary depending on the product (usually the ratio is 2:1 or 1:1). You will have to be very precise, so get the right scale. For example, for small objects it is better to have a precision scale, such as those used by goldsmiths. You can't go even a gram wrong, but no pressure.

Get two clean containers: one for the resin and one for the hardener, which you will have to weigh individually starting with the resin. If you want to use a dye, pour it into the hardener and mix well. Warning: dyes are very effective, usually very little is needed to obtain intense colours, so add a little at a time, stirring often to monitor the effect. You will have to take into account that in the next step you will mix the hardener and the resin, so the color will lose some of its intensity.

Slowly pour the hardener into the resin container; if the latter is too small to contain both, you can use a third clean container, taking care to pour one component at a time. Mix carefully to avoid the formation of bubbles, making sure that the two components are completely mixed.

PRO TIP: Anti-bubble mixers, also called degassers, allow you to mix the two components, avoiding both the formation of bubbles and the dispersion of vapours. They're not essential, but they're pretty convenient

 

 

3. Application

Pour the mixture onto the surface or into the chosen mould, letting it drip very slowly at the shortest possible distance from the surface to avoid air bubbles.

In case you don't want to use a real mold, you can use a release film. It is often used for jewelery creation, as it allows hollow frames to adhere to the work surface (as seen in this video).

As for the molds, they come in all shapes and sizes and you can also use non-specific ones. For example, over the Christmas period we used a chocolate mold to make cute fridge magnets, even though this will prevent us from using it for its original purpose. The important thing is that they are not damp, otherwise the surface of the casting could present a patina. To facilitate the extraction of the object when the resin has hardened, you can sprinkle the molds with the appropriate waxes or release sprays. If you want a matte effect, you can limit yourself to using a thin layer of talcum powder.

PRO TIP: if you work with UV resin, only use transparent molds as the drying of this type of resin depends on the interaction with UV rays, whether they come from the sun or a lamp

 

 

4. Removal of Bubbles

Even if you have been careful to mix the mixture as well as possible and pour it carefully, air bubbles can form in it. To remove them, wait a few seconds for them to rise to the surface and pop them with a heat dryer or a flame torch. You can also use the release film mentioned above: placing it on the surface, pass a rubber spatula from the center outwards, thus eliminating the excess resin.

 

 

5. Hardening

Allow the resin to solidify for the specified time (usually 24 to 72 hours), avoiding moving or touching it. However, after the first 12 hours you can gently handle your creation to manipulate it, for example to give it a slight curvature.

PRO TIP: Check environmental conditions, as humidity and temperature can affect curing.

 

 

6. Finishing

Sand your creation with sandpaper of different degrees of abrasion: start with coarse grain (for example 80 grain) to remove any imperfections or excess resin, move on to medium grain (120-180) to smooth the surface more uniform way; finally, use the fine grain one (220-400) to obtain a smooth and homogeneous surface. Make constant circular movements and avoid putting too much pressure on the surface. Between one step and another, clean the surface with a soft cloth moistened in water to prevent dust or residues from compromising the final result. Remember to wear gloves and a mask!

After completing the sanding of the epoxy resin, you can proceed with polishing the surface to obtain a shiny and smooth result. For this purpose, specific buffing and polishing discs can be used, which allow you to eliminate any residual scratches and give the resin a bright and professional appearance. For example, you can use transparent polyurethane spray suitable for lacquering furniture or transparent acrylic spray found at the hardware store; in any case, it takes at least two or three coats and you will have to wait a couple of hours between one application and another.

 

 

Conclusion

Epoxy resin is an extraordinary material that allows you to unleash your creativity and create unique projects. Knowing its types and the correct way to use it is essential to obtain satisfactory results. Whether you're designing a piece of art, a custom piece of furniture, or a protective coating, epoxy resin can turn your ideas into reality.