A glossy finish epoxy bar top

Epoxy is often applied to materials that otherwise don't fare well with water contact or even light moisture; but what about the epoxy itself—how does water affect it?

How does water affect epoxy?

Once cured, epoxy resin is waterproof.

In fact, this is one of the many reasons why epoxy is such an incredible sealant.

Once it has finished bonding and curing, epoxy will prevent permeation by nearly any liquid or solid material, including water and humid air.

Because of this feature, epoxy is frequently used in garage flooring, on shower walls, and as a coating for outdoor table tops.

Epoxy resin is also easy to clean; common methods such as soap and warm water are quite effective, as well as most multi-surface cleaners.

Just avoid using distilled vinegar as the acetic acid can weaken the surface over time. This is actually good advice for many material types.

Epoxy shower walls in a domestic bathroom

Prior to curing, liquids and moisture can cause problems for epoxy.

Before epoxy finishes curing, it will be in a liquid or semi-solid state. While in this state, water and other liquids can disrupt its ability to bond and cure.

Epoxy resin cures best in dry conditions. While working with it, you’ll want to avoid letting moisture into your work space. If water gets onto epoxy resin before it has finished curing, it can seep into the mixture and cause various problems.

In fact, it may even reach the substrate that your epoxy is bonding to and cause issues there.

Fortunately, it's a problem that's easy to avoid. You can use space heaters and a dehumidifier to maintain ideal temperatures and humidity levels.

Many parts of the U.S. have low humidity to begin with, so that aspect may be a non-issue for some.

Humidity can ruin the visual results of the curing process.

If epoxy resin is allowed to cure in suitable environmental conditions, it will be a transparent, glasslike finish when it's done—provided you haven't applied any epoxy pigments or resin dyes.

However, if epoxy is left to cure in a humid environment, moisture from the air may condensate and interfere with the epoxy resin's ability to cure fully.

When this happens, the most likely outcome is a murky finish that isn't as clear as it should be.

Let's discuss how to avoid these issues.

Two tips on avoiding the humidity problem

If you’ve no choice but to work within a humid environment, there are steps you can take to prevent this from affecting your epoxy project.

Tip #1: Keep the temperature in the ideal curing range.

If you can maintain the temperature of the epoxy workspace within the ideal curing range, the epoxy resin will have a much easier time curing.

This range varies by epoxy type, but the ideal is generally between 70°F to 80°F, with 75°F being the perfect temperature.

Tip #2: Maintain a relative humidity of 60% or less.

Epoxy resin cures best with a relative humidity of 60% or less.

If you live in a humid area, you can use a dehumidifier to control the humidity levels around your epoxy project.

It's also a good idea to keep your project in a well-ventilated but enclosed space. This will make it easier to prevent moisture buildup and reduce the workload of the dehumidifier.

    An epoxy penny countertop with a sink

    Choose a premium epoxy for your resin projects.

    While the information in this guide will enable you to avoid moisture issues during your project, it won't be of much help if the epoxy resin you use is substandard.

    When planning an epoxy project, it's always a good idea to use a high-quality epoxy resin to ensure a satisfying result that lasts as long as it should and doesn't cause you problems later on.

    If you're planning an epoxy project, or merely interested in using epoxy for the first time, we'd love for you to consider our UltraClear Epoxy brand.

    At UltraClear Epoxy, all of our epoxy resins are premium-grade.

    When handled correctly, they'll last for a minimum of 7 years. This lifespan can be further extended with proper care.

    They're also 100% made in the USA.

    This means that when you buy from us, you get the peace of mind knowing that our epoxy products meet the safety and quality standards of the United States, something that many imported brands are not held to.

    You can find our premium epoxy resins on the following pages:

    With UltraClear Epoxy, you'll also get comprehensive customer service. You can contact us through phone or email as well as by text chat on our website by clicking the Help button at the bottom right of your screen.

    Additional Resources

    We hope this article has answered some of your questions.

    Below, we've listed some additional resources you may find useful:

    Have questions? Want advice? Contact us!

    If you have any questions about epoxy resin, or if you'd like advice on 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 right of your screen.

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