Does Non-Yellowing Epoxy Really Exist?

The short answer, no. The long answer, still no. But there are a lot of factors at play. Epoxy resin is everywhere these days. You see it used in statement river tables, sleek countertops, captivating art pieces, and pretty much everything. But if you've worked with epoxy long enough, you might have noticed that familiar, inevitable yellow tint creeping in over time. So, is a "non-yellowing epoxy resin" even a real possibility? Let's dive into the science behind epoxy's yellowing, the steps you can take to slow it down, and the role of product selection in managing that color shift. 

What Causes Epoxy Resin to Yellow?

Yellowing is an inherent trait in epoxy, and understanding why it happens requires a quick look at epoxy's chemistry. All epoxies contain a polymer structure that degrades when exposed to certain environmental factors. Over time, this degradation causes the resin to shift from its crystal-clear appearance to a yellow or amber hue. 

1. UV Exposure: The primary reason epoxy yellows is UV light exposure. Just like how the sun can fade furniture or artwork, UV rays break down the epoxy's molecular bonds, leading to discoloration. Even indirect sunlight can have an impact, which is why epoxy used indoors can still show signs of yellowing. 
2. Oxidation: Oxidation is another contributing factor. Just as metal rusts when exposed to air, epoxy's exposure to oxygen can cause its molecules to break down and change color. 
3. Heat and Humidity: Environmental factors like heat and humidity can accelerate yellowing. High temperatures encourage oxidation, and humidity adds moisture that can also interfere with the stability of resin. 

Are There Truly Non-Yellowing Epoxy Resins?

With yellowing being such a well-known issue, it's no surprise that the industry has developed products marketed as "non-yellowing epoxy resin". While there's no formula that's immune to yellowing, there are options designed to resist and manage yellowing more effectively than traditional formulas. 

Three Ways Manufacturers Enhance Their Epoxy Resin

1. UV Inhibitors & Stabilizers: Many high-quality epoxies are formulated with UV inhibitors. These additives act like sunscreen for your resin, absorbing or deflecting UV rays and minimizing the degradation of the polymer structure. 
2. Advanced Hardener Technology: Some brands have invested in hardeners that are specifically designed to retain clarity over time. These hardeners are often created with a purple tint, combating the natural epoxy yellowing process. 
3. Protective Topcoats: Some epoxy brands recommend or provide topcoats that contain UV-blocking agents. These can significantly delay yellowing, especially for pieces that are placed near windows or have regular sun exposure like tumblers, wall art, and clear encapsulations.

How to Choose a Resin That Resists Yellowing

When selecting an epoxy resin, especially if you're creating a project that is clear with no color additives, it's essential to prioritize formulations that advertise UV stability and added UV inhibitors. Here are some key qualities to look for when evaluating "non-yellowing" epoxy resin options:

• Premium UV Stabilizers: These additives are essential in any resin labeled as "non-yellowing". UV stabilizers reduce the rate of yellowing by minimizing the degradation caused by light exposure. 
• Low-Aromatic Formula: Epoxies made with fewer aromatic chemicals and VOCs typically exhibit a clearer, more color-stable finish. 
• Quality Customer Service: Some premium resins come with certain return policies and expert staff ready to help you navigate yellowing. This shows the manufacturer's confidence in the product's resistance to UV and environmental wear.

Choose the Right Epoxy Resin for Your Project Type

Different project types benefit from different resin properties. For example:

• Art Pieces: When creating artwork, look for a uv-resistant epoxy that's rated for indoor use and offers clarity for detailed or high-gloss finishes. We recommend Promise UV Art Resin.
• Furniture & Countertops: Furniture, especially high-use surfaces like countertops or tables, benefits from resins with UV resistance AND a hard cure given that they'll experience varying light exposure. If you're adding a dark colorant to your pour we recommend Promise Table Top Epoxy. However, if you're adding white pigment, lighter color, or doing a fully clear pour we recommend using Promise UV Resistant Resin. 
• Flower Encapsulations: These are tough because there are so many different techniques and factors that go into a quality floral encapsulation. Because you'll want the color of the flowers to pop, you'll need a very clear Deep Pour Epoxy. But, because the piece will likely have varying light exposure, you're also going to want to coat it in Promise UV Resistant Resin.
• Outdoor Projects: If you're working on a piece intended to be outside, consider a resin that specifically states outdoor or marine-grade qualities.

Practical Tips to Reduce Epoxy Yellowing

Beyond selecting a high-quality resin, there are several steps you can take to prolong the clarity of your epoxy. By controlling its environment and adding protective layers, you can extend the "clear life" of your pieces. 

This Might Seem Obvious, But...

• Use Protective Topcoats: A clear topcoat that includes UV inhibitors can add a barrier between your resin and harmful sunlight, even indoors. 
• Place Projects Away from Direct Sunlight: Indoors doesn't always mean UV-free. Make sure that resin projects aren't directly next to windows or in places where light pours in throughout the day. 
• Consider Shade for Outdoor Pieces: If you're using epoxy outdoors, keep it under a covered space to limit direct UV exposure. 
• Use Darker Colorants: One of the best ways to manage epoxy yellowing is to use darker colorants in your projects. Whether it's black mica's, blue alcohol inks, or something in between, using darker pigments is a great way to forever hide the inevitable yellowing. 

Control Temperature & Humidity

• Store Resin in Cool, Dry Areas: Heat and moisture speed up oxidation and yellowing. Store your bottles of unused resin in a cool, dark location with low humidity. 
• Avoid High-Heat Environments: For example, using an epoxy-coated tray as a hot plate or leaving a resin coaster in direct sunlight can cause yellowing. Keep epoxy pieces away from high-heat areas to preserve their clarity and shape. 

Maintain Your Non-Yellowing Epoxy Resin Projects

Regular upkeep can also go a long way toward minimizing yellowing. Dusting and gently cleaning surfaces ensures that the resin's UV-protective layers are effective. Avoid harsh chemicals and abrasive cleaners, which can degrade the resin surface over time. 

Common Misconceptions About "Non-Yellowing" Epoxy Resin

Let's clear up some common myths:

1. Myth: "Epoxy won't yellow if it's indoors."
   Fact: Indoor light sources, especially LED and fluorescent bulbs, can emit UV light. While it's not as intense as sunlight, over time, even indoor light can affect epoxy. 
2. Myth: "All advertised non-yellowing epoxy resin products are the same."
   Fact: UV resistance varies widely across brands and products. Some might last years without yellowing, while others may begin to show discoloration after a few months. For example, all of Promise Epoxy's products have added UV inhibitors, but our UV Art Resin is the most UV-resistant within our product lines. 
3. Myth: "Using an epoxy with UV inhibitors will prevent yellowing permanently". 
   Fact: They will help manage and prolong epoxy yellowing, but unfortunately epoxy is a chemical and will degrade given enough time. 

Why Embracing Yellowing Might Be a Creative Choice

While yellowing might seem like a drawback, it can add a unique, vintage character to some projects. For example, furniture pieces or decor can develop an amber hue that brings warmth and a natural patina-like effect. Many makers embrace this aspect, particularly when working with wood or crafting rustic or retro-inspired pieces. Knowing that yellowing is part of epoxy's life cycle can help you lean into the unique aesthetic and charm it adds. 

Final Thoughts

Ultimately, whether or not you need a non-yellowing epoxy resin depends on your project goals. If you want the clearest, most stable finish, investing in a high-quality, UV-stabilized epoxy is the best choice. But if you're open to an evolving look, a standard resin might still offer the durability you need. 

While a true non-yellowing epoxy resin may not exist in the strictest sense, there are certainly products that resist yellowing better than others. By understanding what causes yellowing and taking proactive steps, you can create long-lasting, beautiful epoxy projects that retain their clarity for as long as possible.