A Detailed Analysis of Resin vs Epoxy: What Are The Differences?

  • Resin Art 101
  • Posted by: carson-rutz
  • Oct 20, 2023

Have you ever wondered about the difference between resin vs epoxy? While they may seem similar, there are some key distinctions that can greatly impact their usage and effectiveness in various projects. In this article, we will break down their characteristics and applications and help you understand when to use each one.

When it comes to resin and epoxy, people frequently interchange these terms because distinguishing between epoxy vs resin is not appropriate terminology. Therefore, when discussing the differences between them, people often compare casting resin vs epoxy resin. It is essential to realize that these types of substances are distinct compounds. In this comparison, we will mainly focus on understanding the differences between casting and epoxy resin in the most detail.

1. Similarities between Epoxy Coating Resins and Casting Resin

Key similarities between epoxy coating resins and casting resin (source: pinterest)
key similarities between epoxy coating resins and casting resin (source: pinterest)

Epoxy coating resin and casting resin have some similarities in the following characteristics:

Notably, both are waterproof and seamless once poured, making them excellent choices in situations where water resistance is crucial. Additionally, both substances are thermoplastics and generate heat as they cure, ensuring a strong and durable final product. 

Furthermore, their versatility extends to casting molds, enabling users to create various shapes and forms. Another shared feature between resin vs epoxy is the ability to add color before full curing, allowing for customization and unleashing creative potential.

2. Differences between Epoxy Coating Resins and Casting Resin

We have already found some similarities between the two types of substances, so what's the difference between epoxy and resin?

Features Casting Resin Epoxy Resin
Composition Solid or highly viscous material derived from plants or synthetics A polymer consisting of two main components: resin and hardener
Cure Times Cures slower than epoxy Cures very quickly
Strength Less durable and prone to shattering Superior strength
Adherability Adhesion to specific materials Adhesion to various materials
Transparency Transparent nature and a range of colors when pigmented Clear and transparent nature
Viscosity Thinner Thicker
Mixing Ratios Varied mix ratios Easy mix ratios
Maximum layer thickness Several inches in depth Pouring depth ranging from 1/8 to 1/4 inch
Processing Time Longer Than Epoxy Resin (about 120 minutes) Short (approximate 20 minutes)
Surface hardness Typically harder Not as hard as epoxy
UV Resistance See yellowing apparently when outdoors Have resistance to yellowing
Heat Resistance or Tolerance Lower heat resistance than epoxy Higher heat resistance or tolerance
Air bubbles possibility High chance of bubbles forming due to its thickness Less visible bubble formation than casting resin because  of its thinness
Applications Often used for casting purposes, such as creating molds, figurines, and jewelry Often used for coating applications

Now that we have an overview of resins vs epoxy, it's time to dig deeper into each aspect to answer the question: What is the difference between epoxy and resin?

2.1. Composition

What is Resin?

The resin (source: artresin)
the resin (source: artresin)

Resin is a general term for a variety of polymers, including epoxy resin. In more detail, Resin is a solid or extremely viscous substance derived from plants or synthetic materials that may be converted into polymers.

  • Resin's Natural-Based Origin: Resin can be obtained from various sources within a plant, including the entire plant itself, specific parts, or as a result of injury or incisions made to the plant. Examples of plants that yield resin include Benzoin, ginger, pines and firs, and capsicum,...
  • Resin’s Synthetic Origin: Synthetic Resins are created through the curing of rigid polymers. During the curing process, they develop reactive end groups such as epoxides or acrylates.

Natural resin is commonly used in varnishes, adhesives, and as an ingredient in cosmetics and perfumes. On the other hand, synthetic resin finds its use in dental components, industrial prototypes, and decorating supplies like paints and coatings, making acrylic glass or Plexiglass, 3D Printing,...

There are many kinds of these combinations with specialized formulas. The most popular resins are listed below:

  • Urethane resin: This glossy water-based urethane offers excellent protection and a shorter working time. It is perfect for coating concrete, glass, wood, and metal. Besides, it's VOC-free, non-toxic, and has almost no odor.
  • Polyester resin: It's a synthetic resin that is unsaturated. Besides, manufacturers in the marine industry often use this resin for boat building casting bumpers or gutters,...
  • Casting resin: They are specifically designed for mold-making, figurine creation, deep pouring, and jewelry making. They have low viscosity and are able to fill small gaps and holes.
  • Epoxy coating resin: Epoxy coating is an excellent choice for coating rough surfaces due to its water-resistant properties. It can also be customized for an attractive finish using color pastes, alcohol inks, and pigments.

What is Epoxy?

Some overview about epoxy (source: amazon)
Some overview about epoxy (source: amazon)

Epoxy is a polymer consisting of two main components: resin and hardener. These two components are mixed together in specific ratios to initiate a chemical reaction that forms a strong and durable bond. Simply stated, epoxy is just cured epoxy resin. This implies that after the epoxy resin has solidified and completely cured, it will be referred to as epoxy.

Epoxy is commonly used to repair broken objects or create a sealant. When mixed, it hardens and creates a strong bond, making it perfect for fixing items like vases, figurines, ornaments, and more. Besides, people also use it in crafts and art creation, electronics, and electrical components,...

There are some popular types of epoxy: 

  • Epoxy Acrylates: Polyester and pure epoxy resin are combined to form a strong type of epoxy. It is used in woodworking, furniture, and flooring. This versatile coating provides outstanding qualities for both flexible and rigid industrial plastic applications.
  • Epoxy Vinylester: Vinylester is a type of epoxy resin that is modified with styrene. It is commonly used in demanding applications like corrosion-resistant tanks, pipes, automotive and marine vehicles,...

2.2. Curing Time

Compare curing time between two types of substances (source: istock)
compare curing time between two types of substances (source: istock)

Compared to epoxy resins, casting resins cure more slowly. Typically, casting resins take around 36 - 48 hours to fully cure, while epoxy resins cure within 12 - 24 hours. It is worth noting that epoxy resins start to gel in as little as 20 minutes, whereas casting resins may require up to 18 hours to reach the gel state. 

Casting resins have the benefit of allowing thicker pours, which implies that they distribute heat (exotherm) more slowly than coating epoxy. On the other hand, if you leave some coating epoxies in a mixing container for more than 5 - 10 minutes, they will undergo an accelerated reaction, resulting in the production of excessive heat.

2.3. Strength

Epoxy resin in aircraft (source: v-sure)
epoxy resin in aircraft (source: v-sure)

Resin vs epoxy are both commonly used materials in various applications, but what is the difference between resin and epoxy in terms of strength?


Epoxy stands out among resin types due to its superior strength, which makes it perfect for demanding uses like boat construction and aerospace engineering. This epoxy can be in liquid or kneadable form before curing. It boasts twice the strength of concrete, along with excellent chemical resistance.

Moreover, epoxy resin is highly resistant to acids, alkaline, and solvents, which helps maintain its structural integrity and shields against corrosion. In the automotive sector, manufacturers often use this type of epoxy for car parts exposed to corrosive liquids or chemicals such as batteries or fuel systems. Besides, the epoxy could be utilized as a protective coating for the hull of a boat in the marine industry.

Moreover, epoxy resin finds frequent usage in applications that need outstanding adhesion and structural integrity, such as carbon-fiber composites for aircraft structures and adhesives for structural connections and repairs in airplanes.


Resin tends to be less durable and prone to shattering. However, the strength and properties of resin can differ depending on the specific type used, with some being more flexible or rigid, and even possessing unique optical qualities. 

For example, polyester resin is known for its high strength and rigidity, which is used in the production of automobile parts, boat hulls, medical equipment, swimming pools, ponds, molds,... Resin is typically in liquid form until it undergoes the curing process.

2.4. Adherability

Are epoxy and resin the same in adherability? (source: forbes)
are epoxy and resin the same in adherability? (source: forbes)


Epoxy resin demonstrates exceptional adhesion to various materials, including wood, rubber, plastic, metal, and cement-based substrates. This means it can effectively join wooden pieces, secure metal components, seal plastic parts, and even repair cracks in cement structures.


The resin forms a strong bond with specific materials like wood, plastic, glass, metal, and ceramics when we compare resin vs epoxy. Specifically, people use it to bond cracked ceramics, pieces of wood, PVC pipes, or acrylic sheets,... The compatibility between the resin and the material is essential to obtaining good adhesion.

2.5. Transparency

Difference between epoxy and resin in terms of transparency (source: epodex)
difference between epoxy and resin in terms of transparency (source: epodex)


Epoxy resins are well known for their clear and transparent characteristics, making them an increasingly common choice in the creative and coating sectors. They can be formulated to create a crystal-clear finish, which is highly sought after in areas like jewelry making and art projects. Compared to other resin types, epoxy stands out with its exceptional clarity, making it the ideal option when transparency is crucial.


Resin comes in various forms, with some being transparent by nature and others available in a range of colors when pigmented. Natural resins, usually organic and flammable, have a yellowish to brown hue and can be fusible and translucent. Popular resins like UV resin, art resin, and deep pour resin are all naturally clear and transparent.

2.6. Viscosity Consistency

Viscosity consistency (source: alidajzj. En)
viscosity consistency (source: alidajzj. En)

Viscosity is a term used to describe epoxy resin's thickness or flow resistance. Casting resins are thinner than epoxy coating resins as they cure slower and generate less heat. This characteristic enables them to be poured in thinner layers and flow easily, offering more flexibility in various casting applications.

Some resins exhibit low viscosity, while others have high viscosity. Polyester resin falls into the low viscosity category. In contrast, Phenolic Resins are Newtonian liquids with high viscosity, even under high shear rates.

2.7. Mixing Ratios

Mixing ratios (source: etsy)
mixing ratios (source: etsy)

Epoxy resin kits include obvious mixing directions. You should mix Part A (the resin) with the appropriate amount of Part B (the hardener) based on the specified volume. It's crucial to follow the instructions and maintain the correct ratios. If you deviate from the required ratios, your resin may not cure correctly.

In general, many casting resins have different mixing ratios, such as 3:1, 2:1, and 1:1. Conversely, epoxy coating resins are used with a 1:1 mixing ratio, which makes them simpler to operate with. If you opt for different ratios like 3:1 or 2:1, it's important to use specific mixing containers and add the resin gradually to ensure accurate measurements of the ratios.

*Note: Whatever mixing ratio you use, it is highly advisable that you should measure out resin vs epoxy accurately, or else your epoxy will not cure properly.

Unsure about how to properly mix the ratio for epoxy resin? Watch this informative video for clear instructions and expert tip:

2.8. Maximum layer thickness

Epoxy coating resins typically have a suggested pouring depth ranging from 1/8 to 1/4 inch per application. It is critical to comply with this suggestion since exceeding these limitations might result in a quicker curing process. This means that the epoxy may harden too quickly, potentially affecting the quality of the coating.

In contrast, casting resins are known for their ability to accommodate thicker layers per application, sometimes up to several inches in depth. As a result, they are perfect for tasks that need embedding multiple items deep within the resin.

2.9. Processing Time

Analyze the processing time between resin vs epoxy (source: resin expert)
Analyze the processing time between resin vs epoxy (source: resin expert)

The processing time, also called pot or gel time, refers to how long it takes for epoxy to start to gel or set. Once this point is reached, you can face difficulty working with or removing any bubbles that form.

Epoxy coating resins offer a processing time of approximately 20 minutes, allowing for quicker preparation and pouring. However, it's important to note that working time can be further reduced on hot days or if the resin is left in the mixing container for too long before pouring.

Casting resin is known for its thicker layers compared to epoxy coating resin, resulting in a longer processing time as it cures at a slower pace. For example, Epoxy Flow casting resin for medium-sized castings has a processing time of about 120 minutes. This extended time frame allows for more flexibility and precision in various projects.

2.10. Surface hardness

The hardness between resin vs epoxy (source: youtube)
The hardness between resin vs epoxy (source: youtube)

Are you wondering about the processing time difference between resin vs epoxy? Now let's discover the key factors that influence the surface hardness below:

Your epoxy coating resins are typically harder than the casting resins due to the flexibility allowed in the mixing ratios of the casting resins. For instance, if you use casting resins to create artificial water in a vase, it is crucial for the resin to be flexible. The vase will ultimately fracture if it lacks flexibility when the glass shrinks and expands.

To make your application more flexible, adjust the amount of hardener used when using casting resins. Furthermore, epoxy coating resins have been shown to be more scratch-resistant than casting resins.

2.11. UV Resistance

Uv resistance ability when comparing between resin vs epoxy (source: lovegolfmk. Live)
uv resistance ability when comparing between resin vs epoxy (source: lovegolfmk. Live)

Both casting resin vs epoxy coating resin have the ability to include UV inhibitors. However, when using casting resin for outdoor projects, it is more apparent to see yellowing due to its thickness when exposed to UV rays. Additionally, if these resins are not mixed with paint, stain, or color, the yellowing effect becomes even more noticeable.

Different epoxy resins vary in their resistance to yellowing. Epoxy coating resins, in particular, demonstrate better concealment of yellowing when they combine dark-colored stains and paint or when applied to wood grain.

*Note: Keep in mind that epoxy coating resins and casting resins are not suitable for outdoor projects or areas with constant exposure to UV rays.

2.12. Heat Resistance or Tolerance

Heat resistance or tolerance (source: amazon)
Heat resistance or tolerance (source: amazon)

Most of the epoxy coating resins and casting resins commonly used by DIY artists are not highly heat resistant. So are epoxy and resin the same when comparing heat resistance or tolerance? At temperatures ranging from 110 to 150°F, most epoxy coating resins and casting resins begin to soften.

DIY enthusiasts interested in projects like coasters, countertops, or any other project involving the use of hot items such as pots, coffee cups, and pans should carefully consider this aspect.

However, there are some heat-resistant epoxies with the ability to tolerate temperatures as high as 600°F, which are used for flooring, kitchen countertops, mechanical repair,... The maximal heat resistance level of resin might differ based on the type of resin utilized. Some resins, such as phenolic resins, can withstand temperatures of up to 300℃ (550°F).

2.13. Air bubbles possibility 

What's the difference between epoxy and resin regarding air bubbles possibility? (source: davidneat)
what's the difference between epoxy and resin regarding air bubbles possibility? (source: davidneat)

Both resin vs epoxy are equally prone to the production of bubbles on the substrate and enclosed products. When pouring casting resin into a mold with embedded items, there is a high chance of bubbles forming. However, if the resin is poured in thinner layers, the likelihood of bubbles forming decreases as they rise to the surface and can be easily popped.

By taking the time to properly prepare your project beforehand, you can significantly reduce the likelihood of bubbles forming. Begin by applying a thin seal coat to porous surfaces, such as wood, as this allows the epoxy to penetrate and seal any porous areas while enabling trapped air to easily escape. 

Additionally, make sure to seal any items that will be encapsulated before adding resin vs epoxy to your project. Objects with numerous grooves, corners, and open spaces tend to trap air within epoxy projects, so you should seal them beforehand is crucial.

2.14. Applications

Understanding the key differences in applications of resin vs epoxy (source: istock)
understanding the key differences in applications of resin vs epoxy (source: istock)

Epoxy resins are designed for coating applications, while casting resins are specifically formulated for casting purposes, such as creating molds, figurines, and jewelry. However, it's important to note that both resin vs epoxy can still be used for their opposite intended applications with some adjustments.


Epoxy resin for art and decor projects (source: designer-daily)
epoxy resin for art and decor projects (source: designer-daily)

Epoxy resin are popular among artists and craftsmen due to their user-friendly nature and versatility. They are especially suitable for beginners as they are easy to measure and mix.

Moreover, various industries such as construction, automotive, aerospace, electronics, and art extensively utilize these resins. Epoxy resins serve multiple functions, including bonding, laminating, sealing, coating, and acting as glues.


Casting resin in industrial prototypes (source: goodmeowsk. Life)
casting resin in industrial prototypes (source: goodmeowsk. Life)

Resins have diverse applications, including casting, art, jewelry-making, adhesives, and coatings. They can also refer to plant-based resins historically used for varnishes and coatings. Gluing is a rare use for resins.

Casting resin is well-suited for small to medium-scale projects due to its low viscosity and long curing period. Maneuvering the liquid synthetic material into specialized molds is relatively easy.

This makes casting resin a reliable choice for various applications, including dental components (dental crowns, bridges, dentures,...), industrial prototypes (replicate complex shapes and structures), and decorating supplies (resin art, jewelry, decorative objects,...).


In summary, while resins vs epoxy share some similarities in composition, it's crucial to recognize their unique differences in curing time, strength, adherability, and other factors. These distinctions are essential in selecting the ideal resin for your project. If you're seeking further knowledge on resins and other topics, our website offers a plethora of informative posts for you to explore.

Frequently Asked Questions

How do you know if a resin formula is an epoxy resin?

You should read the item's description or label on the resin kit, as well as the precautionary information sheet to make sure everything is safe. When in doubt, you can seek guidance from someone experienced.

Is epoxy and resin the same thing?

No, resin vs epoxy are different. Although epoxy is a particular kind of resin, not all resins are the same or may be used for the same purposes.

Which is better resin or epoxy?

We prefer epoxy in this situation because it is strong and adheres well to different materials. Resin's adhesive ability depends on the type, such as polyester resin which is mainly used for laminating fiberglass and adheres only to itself and certain plastics.

Is casting epoxy the same as epoxy resin?

No, they are different. Casting epoxy is specifically designed for casting larger and thicker objects, while epoxy resin is more commonly used for coating and sealing surfaces.