With every epoxy project, there comes a point where you've done what you can and simply have to let the epoxy cure.
Before being mixed together, epoxy resin is stored as two separately bottled components: hardener and resin. When these two are mixed together, they bond and harden. This process is known as curing.
How Long Does It Take Epoxy to Cure?
The curing process technically begins as soon as you start mixing the epoxy together. For a short period of time at the beginning, curing epoxy has what is known as a "working time" or "pot life". This is the amount of time you have to finish mixing and brush on or pour your epoxy as needed.
During the working time of the epoxy, it's still free-flowing, allow you to apply it to substrates or molds with ease, at which point it will spread out to conform to the surface it's being applied to. Many resins are self-leveling, but not all of them are, as seen with low-viscosity resins.
What Is Curing?
Curing is the phase of the epoxy process during which the epoxy resin changes from a liquid to a solid state.
When the resin and hardener components are mixed together, an exothermic reaction occurs which generates heat and causes the components to change into epoxy proper, gradually hardening into the rock-solid surface epoxy resin is known for.
Giving epoxy adequate time to cure is absolutely essential to achieving a clean, long-lasting finish that with hold up for years to come.
What Are the Ideal Curing Conditions?
For epoxy resin, the ideal curing conditions are the following:
- A temperature of 75°F is perfect, with a minimum recommendation of 70°F.
- A humidity level of 60% or lower is desirable for optimal curing speed.
Without meeting these conditions, your epoxy can still cure, but it will take longer. The temperature is especially important, so if necessary we recommend using space heaters in a temporary enclosure (or small room) to maintain the 70°F minimum.
How Long Does Epoxy Need to Cure?
Epoxy curing has a few thresholds it will reach on the way to its final state:
Threshold #1: 4 to 6 hours of curing.
After 4 to 6 hours, epoxy will be receptive to additional coatings of epoxy. This is most often meaningful when applying your flood coat over your seal coat.
Threshold #2: 10 to 24 hours of curing.
At 24 hours, most epoxy resins will feel quite solid to the touch. Note that this doesn't mean they're usable.
After this much time has passed, it takes a little more effort apply any additional coatings:
- Perform a very light sanding—enough to scuff the surface a little and give the next layer something to "grip" as it bonds to it.
- Wipe the surface clean with denatured alcohol or acetone.
- Apply your additional layer of epoxy over top the previous one.
After 24 hours, the epoxy will gradually continue to harden, getting tougher and tougher until about the 72 hour mark.
Threshold #3: 72 hours.
Once 72 hours have passed, most epoxy finishes will be ready for use. If you're using our Primaloc Bar & Table Top Epoxy, it should be rock-solid, provided you allowed it to cure in suitable conditions.
From this point on, the epoxy will continue to get harder, reaching an incredibly strong state after several weeks.
Ultimately, epoxy resin needs 72 hours to cure, at which point it's usable as a surface.
Do Epoxy Colorants Affect the Curing Time?
With Primaloc Bar & Table Top Epoxy, epoxy colorants won't inhibit the curing process. We can't speak for all other brands, though.
Any good epoxy resin should be fine with them, as they're designed to be used in epoxy resins.
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 and cures clear and strong, with high performance in every category.
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.