Epoxy Resin vs. Polyurethane for Art

Epoxy Resins vs. Polyurethanes for Art – Which one is right for your project? Well when it comes to DIY and crafts projects, choosing the right material is crucial for achieving the desired outcome. Two of the most popular materials in the art world are epoxy resins and polyurethane. Both offer unique properties and benefits, making them suitable for various applications. But how do you decide which one is right for your project? In this blog article, we will compare and contrast epoxy resin and polyurethane, providing guidance on which material is best suited for common art and crafting projects.

Firstly, how do we know what Polyurethanes are? At U RESIN, we bring a wealth of experience to the table. One of our sister companies have been in the Polyurethane Industry as a polyurethane supplier and processor for over 35 years, establishing a strong foundation in the Australian and Global Industry. Building on this expertise, we branched into epoxy resins well over 20 years ago. Now with 3 generations in the industry, we possess decades of knowledge and experience with both polyurethanes and epoxy resin products. This extensive chemical background ensures that we understand the intricacies of each material and can provide the best guidance and solutions for your projects, unlike many other brands, that began as artists’.

Ok so – back to the topic at hand. Lets go through a brief explanation of what epoxy resin and polyurethanes are.

Epoxy Resin: Epoxy Resin is a synthetic thermosetting polymer that is well known for its strong adhesive properties, clarity and durability. It’s a two-part system consisting of a resin and a hardener, which, when mixed together, undergo a chemical reaction to form a rigid, high-strength material (in most cases).

Epoxy Resins are extremely versatile and can be used for a vast range of projects and in numerous industries. Some of the most common uses of epoxies are:
– Art and craft projects
– Tabletop and bar top coatings
– Flooring
– Adhesives
– Marine and automotive repairs

Polyurethanes: Polyurethane is a versatile polymer that comes in various forms, including foams, elastomers, and coatings. It’s known for its flexibility, durability, and resistance to abrasion and chemicals. Polyurethane can be either a one-part, two-part or even three-part system, depending on the specific application and grade.

Polyurethanes are also an extremely versatile product with a large number of applications and industries that use them. Some of the most common uses include:
– Flexible moulds
– Protective coatings
– Foam products (e.g. cushions, insulation)
– Seals and gaskets
– Automotive parts

So now lets compare Epoxy Resin and Polyurethane.

1. Clarity and Finish –

Epoxy Resin: Epoxy resins are renowned for their crystal-clear finishes, making it an excellent choice for art projects or other projects that require a high level of clarity and/or gloss. It can also be polished to a glass-like finish, enhancing the beauty of embedded objects and colours.

Polyurethane: Polyurethane can also provide a clear finish, similarly to what you will find in the Optically Clear Urethanes. BUT in most cases, polyurethanes are amber/honey coloured and foams are largely off-white/cream coloured. So polyurethanes are more often used for its protective properties rather than aesthetics. It comes in both gloss and matte finishes, and while it can be clear, it may not achieve the same level of transparency as epoxy resin.

2. Durability and Hardness –

Epoxy Resin: Whilst you can get soft, flexible epoxy resins, it’s not very common to come across and are more specialised.  Epoxy resin largely cures to a hard, durable finish that is resistant to scratching, impact, and moisture. It’s ideal for projects that require a strong, rigid material.

Polyurethane: Polyurethane offers excellent durability and can be more flexible than epoxy resin, making it resistant to abrasion and impact. It’s often used in applications where flexibility and resistance to wear and tear are essential.

3. Chemical Resistance –

Epoxy Resin: Epoxy resin is highly resistant to chemicals, making it suitable for applications exposed to harsh environments or chemicals.

Polyurethane: Polyurethane is also resistant to many chemicals, but its specific resistance depends on the formulation. It generally provides good resistance to oils, solvents, and other chemicals

4. Application and Work Time –

Epoxy Resin: Epoxy resins generally have a longer pot life before it begins to cure, allowing for detailed work and adjustments. Epoxy resins can also be found with short working times in products like Araldite, but these sorts of pot lifes are not so common in epoxies. With a longer pot life, also means a longer curing time, which can take up to 24 hours or more to fully harden.

Polyurethane: Polyurethane typically has a shorter work time and faster curing time compared to epoxy resin. This can be advantageous for projects that need to be completed quickly but may be challenging for detailed work. Many polyurethane products have a pot life under 10 minutes and a de-mould time within a few hours which can often be helpful when you need to produce large volumes.

5. Flexibility and Versatility –

Epoxy Resin: Epoxy resin cures to a rigid, inflexible finish, which is ideal for structural applications and surfaces that require a hard coating.

Polyurethane: Polyurethane’s versatility shines in its ability to be formulated for various levels of flexibility and hardness. It can be used for flexible moulds, protective coatings, and foam products.

Now that we have done a general comparison between epoxy resin and polyurethanes, the next questions is how do you choose the right material for common art projects.

Resin Art and Casting:
For projects like resin art and casting, where clarity, gloss, and the ability to embed objects are essential, epoxy resin is the ultimate choice. An epoxy resin system with a crystal-clear finish and longer work time will allow for intricate designs and detailed work.

Jewellery:
For Jewellery (depending on the kind) either an epoxy resin or polyurethane can be used. If you are casting with pigments or glitters and looking for a fast system with quick de-mould time, then a polyurethane would be the preferred choice. If you are looking for a high gloss finish or looking to embed items into the jewellery pieces, then you would be best to opt for an epoxy.

Tabletops and Bar Tops:
Epoxy resin is also ideal for coating tabletops and bar tops due to its durability, high-gloss finish, and resistance to moisture and scratches (ensuring you are working with a Countertop specific resin). It will provide a protective and aesthetically pleasing surface.

Flexible Moulds:
When creating flexible moulds for casting, polyurethane elastomer is the better option. Its flexibility and durability make it suitable for repeated use without tearing or losing shape.

Protective Coatings:
For protective coatings on surfaces exposed to wear and tear, such as floors and automotive parts, polyurethane offers excellent abrasion resistance and flexibility, ensuring long-lasting protection. Alternatively a flooring epoxy resin can also be considered.

Foam Products:
Polyurethane is the go-to material for anything foamy/soft. Products like cushions, seating, insulation, and padding. Its ability to be formulated into various densities and levels of firmness makes it highly versatile for these applications.

Both epoxy resins and polyurethanes have their unique strengths and are suited to different types of projects. Understanding the properties and benefits of each material can help you make an informed decision based on your specific needs. By selecting the right material for your project, you can ensure a successful outcome that meets your artistic and functional requirements. If you are new to the world of resin, we have a resin compatibility chart available on our website that will compare all of our epoxy resin systems and what projects they are best for. If you are wanting to learn more about Polyurethanes or are looking for a particular foam or elastomeric product, head over to our U RESIN Industrial website. This is where you will find a large selection of polyurethane products for various applications. Happy crafting!