Epoxy resin and wood varnishes are popular options for sealing wooden surfaces, each providing a protective coating that helps shield the wood from various forms of damage. While the specific protection offered varies among varnish types, moisture resistance is a common feature in nearly all varnishes.

In this article, we'll explore six reasons why epoxy resin is superior to other varnishes when it comes to sealing wood surfaces.

What Is a Varnish?

Varnish is a clear, protective coating often applied to wood, though it can also be used on other materials. It traditionally consists of a mixture of drying oil, resin, and a solvent or thinner. Varnish cures through exposure to air, as it reacts with oxygen.

The characteristics of the protective film that varnish creates on a surface vary depending on the types of resin and oil used in its composition.

A Summary of Varnish

There are three major aspects of a varnish:

• Composition
• Type
• Purpose

Below we'll describe these three aspects in more detail.

The Composition of Varnish

• Drying Oils: Common oils used in varnishes are linseed oil, tung oil, and walnut oil. These oils help the varnish to solidify as they oxidize upon contact with air.

• Resins: Resins provide the substantive body of the varnish and influence many of its properties. Widely used resins in varnishes include alkyd, polyurethane, acrylic, and phenolic resins, each offering varying levels of hardness, durability, and resistance.

• Solvents or Thinners: Solvents like mineral spirits or turpentine adjust the varnish’s viscosity and facilitate its application. As the varnish dries, these solvents evaporate, allowing the resin and oil to cure into a durable film.

Different Types of Varnish

• Oil-based Varnish: Composed of drying oils and resins, oil-based varnishes offer a robust, water-resistant finish. They are particularly suited for surfaces that encounter moisture.

• Polyurethane Varnish: Recognized for its durability, polyurethane varnish provides excellent resistance to abrasions, scratches, and chemicals.

• Spar Varnish: Specifically formulated for outdoor applications, spar varnish includes UV blockers to protect against sunlight and is flexible enough to handle the wood’s expansion and contraction due to weather variations.

• Acrylic Varnish: A water-based option that dries quickly, acrylic varnish emits fewer odors and is more environmentally friendly than traditional oil-based varnishes.

Typical Purposes of Varnish

• Protection: Varnish creates a tough, protective layer over wood, shielding it from water, dirt, and wear. This coating significantly prolongs the wood's durability.

• Aesthetics: Varnish enhances the natural appeal of wood, providing a rich, glossy (or satin, depending on the chosen finish) look that deepens the wood grain's color.

• Special Applications: Some varnishes are tailored for particular uses, like marine varnish for boats, which is formulated to resist saltwater and sunlight more effectively.

While varnish is a versatile and effective method for protecting wooden furniture, flooring, and decorative items, it often falls short in terms of physical durability and is prone to scratching. These scratches can compromise the protective seal, potentially exposing the underlying material to the types of damage the varnish is supposed to prevent.

Despite this, varnish's broad spectrum of formulations makes it suitable for a variety of environments and applications, securing its place as a mainstay in both amateur and professional woodworking. However, for many users, there is a superior option for protecting and enhancing their surfaces—epoxy resin.

6 Advantages of Epoxy Over Varnishes for Wood Sealing

Selecting the right sealant for your wood surfaces is a decision that requires careful consideration. Each type of varnish comes with its own advantages and drawbacks, excelling in certain areas while falling short in others.

But that's not so for epoxy resin, a type of sealant that generally outperforms others across various categories of protection. This sealant is renowned for its superior durability and effectiveness in safeguarding surfaces.

Six Aspects in Which Epoxy Excels:

• Physical Durability and Hardness
  
• Resistance to Moisture
  
• Aesthetic Customizability
  
• Sealant Depth and Self-Leveling
  
• Chemical Resistance
• Sealant Lifespan

We'll dive into each of these aspects below.

Aspect #1: Physical Durability and Hardness

Epoxy resin creates a surface that is significantly harder and more durable than varnish.

When fully cured, epoxy forms a tough, plastic-like layer that is exceptionally resistant to impacts, scratches, and regular wear and tear. This robustness makes it especially suitable for high-use areas like table tops, bar tops, and floors.

On the other hand, while varnish does offer a layer of protection, it is generally softer and more susceptible to scratches and dents as time passes. Although some varnishes, such as polyurethane, approach the resilience of epoxy, none can fully match its overall durability.

Aspect #2: Resistance to Moisture

Another key advantage of epoxy is its outstanding moisture resistance.

Epoxy forms a waterproof seal that entirely protects the wood from water damage, staining, and warping. This characteristic is especially valuable for wooden items exposed to outdoor conditions or placed in humid settings such as kitchens and bathrooms.

While varnishes do offer some level of moisture resistance, they lack the complete impermeability of epoxy and can allow moisture to seep through, particularly if the finish is marred in any way.

Aspect #3: Aesthetic Customizability

Epoxy stands out for its aesthetic versatility as well.

It can be applied as a clear, glossy finish that amplifies the natural allure of wood grain, or it can be tinted with various dyes and pigments to achieve an array of colors and visual effects.

Additionally, epoxy is capable of enveloping objects like coins, photos, or leaves within its clear, glossy substance, allowing for the creation of uniquely decorative items. While varnishes do enhance the natural color and texture of wood, they lack the extensive customization and artistic possibilities provided by epoxy.

Aspect #4: Sealant Depth and Self-Leveling

Epoxy distinguishes itself by the ability to be applied in much thicker layers than varnish without the risk of running or sagging, due to its self-leveling properties. This allows for a thicker, more substantial coating in a single application, which provides a deep, glossy finish capable of filling in cracks and imperfections in the wood.

Additionally, there are specialized epoxy resins designed for extremely deep finishes, known as Deep Pour Epoxies.

The thickness of epoxy not only enhances durability but also contributes to the depth and clarity of the finish, qualities that are challenging to replicate with varnishes.

Aspect #5: Chemical Resistance

Epoxy coatings excel in chemical resistance, making them ideal for settings where exposure to solvents, oils, and other harsh chemicals is common. This resistance helps maintain the integrity of the finish and ensures the wood underneath remains protected even in demanding environments.

In contrast, varnishes, depending on their specific formulation, tend to be more vulnerable to chemical damage, which can lead to staining or a deterioration of the finish.

Aspect #6: Sealant Lifespan

Thanks to its incredible composition, an epoxy finish generally outlasts a varnish finish under comparable conditions. Epoxy's outstanding resistance to fading, yellowing (when UV stabilizers are used), scratching, and peeling greatly enhances its durability, minimizing the frequency of refinishing.

Although the initial cost may be higher than that of varnish, epoxy proves to be more economical over time due to its extended lifespan—just be sure to avoid low-quality, budget-brand epoxies.

Learn more about epoxy longevity in our guide to the subject here!

Primaloc Epoxy: Premium Epoxy for Premium Results

With our premium Bar & Table Top Epoxy and our Deep Pour Epoxy, Primaloc gets the job done. Our epoxy resins are premium-grade, with high performance in every category, including:

• Unmatched Strength: A Primaloc finish won't buckle, even under high pressure.
• Long-Lasting Resilience: Primaloc epoxy lasts for many years with minimal care, and can endure high-traffic environments with ease.
• A Crystal-Clear Coating: With its pristine, transparent appearance, looking at a cured Primaloc coating is like peering through a window.

Epoxy resin can be beautiful, strong, and long-lasting—which is why you shouldn't compromise on quality. With Primaloc Epoxy Resin, you get the ultimate finish in durability and visual appeal.

Protect your surfaces by giving them a rock-solid epoxy finish. Choose strong. Choose reliable. Choose Primaloc.