Planning an epoxy project can involve few or many steps, but one that is always present is the choice of epoxy to be used. For epoxy projects, there are typically several possible types of epoxy worth considering, each with their own upsides, downsides, and areas where they truly excel.
One aspect of epoxy resin that plays a major role in how the epoxy behaves during application and curing is its viscosity. How it blends, bonds, flows, and cures are all affected by viscosity.
Throughout this article, we'll be detailing the effects of viscosity on the epoxy application process so that you can be better informed when choosing which type of epoxy you want for your own projects.
What is an epoxy's viscosity rating?
Viscosity ratings are how we measure the way epoxy flows. Much like comparing water to syrup, an epoxy with low viscosity will flow freely and swiftly, whereas one with a high viscosity rating will move more gradually and smoothly.
At UltraClear, we offer 3 high-grade epoxy variants designed for professional and DIY use. These are:
- UltraClear Bar & Table Top Epoxy—High viscosity.
- UltraClear Deep Pour Epoxy—Low viscosity.
- UltraClear Art & Craft Epoxy—Medium-high viscosity.
As we discuss various factors mentioned below, we'll also detail how they're impacted by each of our resins.
6 ways in which viscosity affects an epoxy's performance
There are six particularly noteworthy ways in which viscosity influences the behavior of epoxy during application:
- Applying the epoxy
- Removing air bubbles
- Seal coat applications
- The ability to self-level when poured
- Total curing times
- The strength of the cured finish
Below, we'll examine these, one by one.
Viscosity Effect #1: How easy it is to apply an epoxy.
An epoxy that is notably viscous (i.e., thicker), such as our UltraClear Bar & Table Top Epoxy, will be more resistant to movement, thereby spreading out more slowly and making it easier to apply to vertical surfaces and uncontained surfaces.
In contrast, an epoxy with low viscosity (i.e., thinner, more watery) like our UltraClear Deep Pour Epoxy will mix and pour very easily, but can flow right off the edges of a surface. This means that while it usually needs to be contained by something (e.g., the substrate, rails, a temporary dam, etc.), it can conform to irregular shapes without issue, making it excellent for filling in odd spaces.
An epoxy that sits in between high and low viscosity can fare well in both manners when only a little bit of extra leeway is needed. This makes the UltraClear Art & Craft Epoxy effective for resin art.
Viscosity Effect #2: How well air bubbles can be removed.
Managing Air Bubbles in Epoxy Flood Coats
During many epoxy projects, a flood coat is applied to the substrate surface. This stage is when air bubbles are most likely to appear in the resin finish. Proper handling of the epoxy can ensure these bubbles are entirely removed from the final surface.
Impact of Resin Viscosity on Bubble Formation
When working with deep epoxy layers, thicker resins tend to trap more air bubbles because their higher viscosity slows the rise of bubbles to the surface. In contrast, thinner resins facilitate the upward movement and popping of bubbles, significantly reducing the chances of bubbles remaining in the cured epoxy.
To minimize bubble formation in deep layers, selecting a low-viscosity resin is essential. This choice helps ensure that fewer bubbles are created and that those that do form can easily escape to the surface for removal.
Removing Air Bubbles Effectively
The standard approach to eliminating air bubbles involves using a heat gun or blowtorch. These tools help push bubbles to the surface where they can burst, releasing the trapped air into the atmosphere. However, in thicker epoxy layers, some bubbles might remain trapped within the resin if they cannot reach the surface, potentially affecting the finish quality.
Choosing the Right Epoxy for Your Finish
With these considerations in mind, selecting the appropriate epoxy resin based on your project’s needs is crucial:
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For a Strong, Thin Epoxy Finish: Opt for UltraClear Bar & Table Top Epoxy. This resin provides a durable and clear finish suitable for surfaces that require strength without excessive thickness.
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For a Deep Epoxy Finish: Choose UltraClear Deep Pour Epoxy. Its low viscosity is ideal for creating deep layers, allowing epoxy to flow smoothly and minimize bubble formation.
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For a Slightly Thicker Finish: Use UltraClear Art & Craft Epoxy. This option offers a bit more thickness than standard table top epoxies, making it suitable for projects that need a moderate increase in resin depth.
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For Maximum Depth and Strength: Combine UltraClear Deep Pour Epoxy with a topcoat of UltraClear Bar & Table Top Epoxy. Start with the Deep Pour Epoxy to achieve the desired thickness, then apply the Table Top Epoxy as a protective final layer to enhance durability and provide a flawless seal.
By selecting the right epoxy resin for each specific aspect of your project, you can achieve a high-quality, bubble-free finish that meets your aesthetic and functional requirements.
Viscosity Effect #3: The ability to apply a seal coat of epoxy.
Epoxies with higher viscosity are best-suited for seal coat applications. Their thicker consistency helps the seal coat remain in place, allowing it to penetrate the porous substrate and form a strong bond while also displacing any trapped air.
For seal coating, we recommend using our UltraClear Bar & Table Top Epoxy. In deep pour epoxy projects, it's effective to use this epoxy for both the seal coat and as a final protective topcoat, ensuring maximum protection and durability.
Viscosity Effect #4: Whether or not an epoxy is self-leveling.
Epoxies with lower viscosity spread quickly across surfaces with minimal effort, offering almost no self-leveling capabilities. In contrast, higher viscosity epoxies also self-level but may require more time and careful pouring to ensure thorough coverage.
Additionally, the surface tension of an epoxy resin influences how thin it can spread before leveling out, regardless of its viscosity.
In most cases, these factors should not significantly impact the choice of resin for a project.
Viscosity Effect #5: How long it takes epoxy to cure.
The viscosity of an epoxy affects how long it takes to cure. Generally, thicker epoxy mixtures require more time to harden compared to thinner ones. However, the exact curing time can vary based on the specific epoxy formulation.
For most users, the difference in curing times is minimal and does not significantly impact typical projects, regardless of the epoxy chosen.
Viscosity Effect #6: The strength of a fully cured epoxy finish.
The viscosity of epoxy plays a role in the appearance of the finished project. Thicker epoxy tends to create a more resilient coating, offer exceptional protection. In contrast, thinner epoxy spreads more easily, resulting in a smoother, glass-like surface.
However, other factors also influence the strength and clarity of an epoxy finish.
To achieve the best possible finish, follow these steps:
- Accurately measure and mix: Ensure you measure and mix the epoxy components correctly.
- Provide proper curing conditions: Allow the epoxy to cure in an environment with suitable temperature and humidity.
- Carefully choose your epoxy: Use a high-quality epoxy resin that is appropriate for your specific project needs.
Choosing the right epoxy at UltraClear
At UltraClear, we offer three primary types of epoxy resins tailored for furniture and fixture projects: Bar & Table Top Epoxy, Deep Pour Epoxy, and Art & Craft Epoxy. Each resin is designed for specific applications, with Bar & Table Top Epoxy being the most frequently used as a sealant. Here’s a breakdown of each:
UltraClear Bar & Table Top Epoxy: High viscosity and strength
UltraClear Bar & Table Top Epoxy is the preferred choice for projects such as bar tops, table tops, and countertops. These applications generally do not require specialized resins like Deep Pour Epoxy.
Benefits of Table Top Epoxy:- Strength: One of the strongest clear resins available.
- Seal Coating: Ideal for applying a seal coat before the main epoxy layer.
- Self-Leveling: Consistently self-levels to 1/8 inch.
The high viscosity of Table Top Epoxy makes it suitable for complete project use, from sealing to the final coating. Its reliable self-leveling property also makes it a good option for those new to epoxy projects.
You can purchase UltraClear Bar & Table Top Epoxy in our store.
UltraClear Deep Pour Epoxy: Low viscosity for thick layers
UltraClear Deep Pour Epoxy is formulated for applications that require thick resin layers, up to 2 inches at a time. This makes it suitable for projects like river tables and various resin art endeavors.
Advantages of Deep Pour Epoxy:
- Low Viscosity: Flows easily, allowing air to escape and reducing bubble formation even in thick layers.
- Thick Layers: Can be poured in substantial amounts without compromising the finish.
We recommend using Deep Pour Epoxy for projects that need significant resin depth, as it helps achieve a clear and uniform cure.
UltraClear Deep Pour Epoxy is available in our store.
UltraClear Art & Craft Epoxy: Medium-high viscosity for resin art
UltraClear Art & Craft Epoxy is designed specifically for resin art projects. It offers a balance between strength and pourability, making it suitable for a variety of artistic applications.
Features of Art & Craft Epoxy:
- Versatile Viscosity: Slightly lower strength than Table Top Epoxy but allows for thicker pours than standard resins, though not as thick as Deep Pour.
- Customization: Ideal for embedding objects and creating detailed designs in projects like coasters, tumblers, and paintings.
Choose Art & Craft Epoxy for creative resin art projects that require both flexibility and durability.
You can find UltraClear Art & Craft Epoxy in our store.
Have questions? Want advice? Contact us!
If you have any questions about epoxy resin, or if you'd like assistance in planning an epoxy project, please reach out to us at UltraClear Epoxy—our epoxy experts are ready to assist!
You can contact us via phone or email here. During business hours, you can also text chat online with one of our resin specialists by clicking the Help button at the bottom of your screen.
In our online store, you'll find a variety of useful tools and supplies, ideal for resin projects, plus our award-winning UltraClear Bar & Table Top Epoxy and our UltraClear Deep Pour Epoxy.
