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Primaloc Epoxy Basics: How to Store Your Epoxy and Avoid Yellowing

Sometimes when planning an epoxy project, you get your epoxy resin earlier than you need it. Or maybe you didn't use everything you purchased all at once and have some leftover that could be useful for other reason.

When a situation like this occurs, it's useful to know how to store the epoxy—whether sealed or opened—to keep it in optimal condition

In this article, we'll explain how to store epoxy resin in its container, and how to avoid yellowing, both from storage and from outdoor use.

How to Store Your Epoxy and Avoid Yellowing

During delivery, epoxy resin occasionally goes through quite some temperature ranges on the way to its destination, an unavoidable effect of (usually) long-distance travel. It's nothing major to worry about, but it can make the epoxy unusable for a bit if, for instance, its left in cold weather awaiting pickup.

While you can't really control the circumstances of delivery, once the epoxy is at your door, you'll be able to store it optimally in anticipation of your next project.

For most epoxy resins, including our Primaloc Bar & Table Top Epoxy, the ideal temperature range to store your epoxy components in is somewhere between 60°F and 80°F. We recommend keeping it in a dry part of your building, a space with low humidity so that it's ready to use at any time.

If your epoxy arrived cold (or excessively, given the weather in some places), you can leave it in a suitably conditioned room for a while until the contents adjust to room temperature.

The Shelf Life of Epoxy Components

Epoxy resin has a limited amount of time during which it can be used in its optimal state. Typically, this is a little over a year after production.

Because Primaloc Epoxy Resin is consistently shipped out to customers shortly after production, we usually suggest a shelf life of 1 year if it hasn't been opened, though technically it is a little longer than that.

Oxidation, the Cause of Epoxy Component Yellowing

Unfortunately, once a container of epoxy resin or hardener has been opened (unsealed), oxygen is induce to the mix, bringing about a reaction called 'oxidation'.

Oxidation is complex chemical reaction, but what it boils down to is a process that causes epoxy to gradually yellow. This isn't immediately a concern, but after a couple months you may start seeing the effects.

The issue itself can be avoided by using the epoxy within roughly two months of opening the containers. On the other hand, if the aesthetic aspect of yellowing doesn't bother you—for instance, if you're tinting your epoxy with powder pigments or plan to paint the finish afterward—then this concern becomes much less of an issue and more of an interesting bit of trivia, as the epoxy's key attributes, such as high durability, won't be affected.

With Primaloc Epoxy Resin, and most resins in general, your shelf life once you open a component container is immediately reduced to 2 months. So, try to use it in that time if you need to avoid the yellowing cosmetic effect, and don't open the containers until you're actually ready to use them.

An outdoor epoxy bar top with a side umbrella shading it from direct sunlight.

UV Radiation: The Bane of Epoxy Clarity and Main Cause of Yellowing

There's one other common cause of yellowed epoxy finishes: direct sunlight.

When the light emitted by the sun hits earth's atmosphere, much of the dangerous and damaging UV radiation is filtered out, leaving behind only a portion of this non-visible light. Still, enough ultraviolet makes it through that it becomes cause for concern.

In humans, UV rays are the cause of sunburn. In epoxy, UV rays can cause yellowing, though thankfully it takes much longer to transpire than a sunburn can—make sure you wear sunblock out there!

Avoiding the UV Rays of Direct Sunlight

While it's not a great idea to place an epoxy project outdoors in direct view of the sun, there are ways to dodge this issue.

For instance, giving your epoxy project a rooftop or overhang can block much of the sunlight when it's at its peak, overhead. In fact, any form of consistent shade is all you really need to protect your epoxy finish from UV radiation.

Another thing you can do to mitigate the issues caused by UV sunrays is to tint your epoxy with mica powder pigments. These are mica-based powder colorants that can be mixed into an epoxy batch to imbue it with a colorful sheen.

The mica powder particles in epoxy pigments are non-soluble and colorfast, so they retain their form and color even in direct sunlight after being mixed into the epoxy. The effect is stunning, but moreover, it also gives the epoxy some resistance to the full breadth of the UV rays damaging effects.

While epoxy pigments will delay UV damage, they don't provide immunity, instead making the finish more resilient. Therefore, we still recommend that your epoxy project be placed in a shaded area, whether through natural means (e.g., trees) or through a fabricated shelter.

An outdoor epoxy resin table with a table umbrella to shelter it from direct sunlight.

Conclusion: How to Store Epoxy and Avoid Yellowing

Now that we've gone into the details, here's a handy summary:

  • Always store your epoxy components in a non-humid location between 60°F to 80°F whenever possible.
  • Keep in mind the shelf life of 1 year for sealed components and 2 months for unsealed.
  • Avoid direct sunlight exposure to your epoxy resin finishes. Provide them shelter and consider epoxy pigments to provide resistance.

Primaloc Epoxy: Premium Epoxy for Premium Results

When it comes to epoxy resin, Primaloc Epoxy gets the job done. Our epoxy resin is premium-grade, with high performance in every category, providing unmatched protection, as well as being receptive to epoxy pigments, for a colorful, charming appearance that brings a boost to UV resistance.

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.


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