Hot Tips: How to Work with Epoxy Resin in Summer Without Losing Your Cool

Summer might be great for beach days, barbecues, and back porch lounging - but it you're working with epoxy resin, rising temps can mean problems. 

If you're resin is misbehaving, you have a problem, and you're not alone. Epoxy resin is temperature sensitive by nature, and warm weather can accelerate chemical reactions, reduce pot life, and leave you with results that are less than stellar. But we've got you. Whether you're an experienced maker or just starting out, we've got the coolest summer survival guide to keep your pours pristine.

Let's break down what heat does to resin, what to watch out for, and how to keep your projects from turning into sticky, bubbly disasters. 

Why Does Resin Freak Out in the Heat?

It's all about chemistry. Epoxy resin cures through an exothermic reaction - meaning it generates heat as it cures. When the ambient temperature is already high (think 80F and above), this reaction speeds up. That sounds good in theory, but faster isn't always better in the resin world. 

Here's what too much heat can do:

• Accelerate the cure too quickly, giving you little time to pour or manipulate your piece.
• Trap bubbles before they can rise to the surface.
• Create surface ripples or warping as temperatures shift mid-cure.
• Lead to soft or tacky finishes, especially if combined with humidity.

Add humidity into the mix, and now you're dealing with blush (that hazy, greasy layer that ruins your topcoat), moisture-induced cloudiness, or even full-on cure inhibition. Luckily, it's all preventable! 

7 Ways to Keep Your Cool When It's Hot Out

We're not saying you have to turn your garage into a climate-controlled lab - but a few tweaks can make all the difference. 

1. Resin Early or Resin Late

Temperature peaks in the afternoon, so avoid working during midday hours when the heat is at its worst. Early mornings or late evenings are your sweet spot. 

Bonus: less sunlight usually means less risk of UV exposure messing with your pour. (More on that below). 

2. Work in the Shade

Whether you're pouring indoors near a sunny window or working in your backyard, light and heat go hand in hand. Keep your projects (and your resin supplies) out of direct sunlight. Use a canopy, umbrella, or even use a pop up tent if you have to work outside. Working inside? Block harsh sunlight with curtains or blinds while still keeping the air flowing. 

And whatever you do: don't cure your project on a metal table that's been sitting in the sun all day.

3. Cool Your Workspace

You don't need a lab-grade HVAC system - but some temperature control can help. Use an air conditioner, portable AC, or even a dehumidifier to bring temps and moisture down. Just avoid using a high powered fan that stirs up dust or blows debris onto your pour. If you need airflow, go low and slow, like a gentle oscillating fan positioned away from your project. 

Pro Tip: Before pouring, wipe down any surfaces, clean your mold, and spray an anti-static dust remover (like alcohol mist) to keep airborne bits from getting into your project. 

4. Slow It Down

Heat speeds up curing, which means your pot life (the amount of time you have to work with mixed resin before it starts setting up) shrinks. That's a recipe for panic. For projects where you need to pour over 1.5" use a slow curing deep pour formula, which naturally has a longer working time. In summer, even your "fast" resin might feel turbo charged, so switching to a slower option gives you back your control. 

However, you still need to be sure you are using the right reason for your application. Not all projects can use a deep pouring resin. 

5. Watch the Thermometer

Most epoxies work best in temperatures between 70F-75F with low humidity. Anything higher or wetter than that, and you're inviting chaos. Use a combo thermometer/hygrometer to monitor your space. You can find inexpensive ones online or at hardware stores. Keeping tabs on the environment lets you plan your pours more strategically. 

6. Store Your Resin Properly

Don't store your resin in a hot shed. Period. Don't store your resin in a sunny studio or your car. High storage temps will degrade your resin before you even open the bottle. Instead, store both parts A and B in a cool, dark cabinet indoors. And always let your resin come back to room temperature before mixing. This helps avoid mixing issues and micro bubbles. 

Pro Tip: Some makers stash their resin in a cooler (with no ice) just to buffer temperature spikes during heat waves. 

7. Adjust Your Expectations (and Your Batch Sizes)

If you're used to working with 8oz batches in spring, you might need to scale back to 4oz or smaller when it's hot. Smaller batches generate less internal heat, giving you a little more time to work. And definitely don't expect your normal 30-40 minute pot life in 90F heat - it's more likely to be 15-20 minutes. Set a timer and prep everything before you mix. 

Reminder: Mix slower, not longer. Vigorously mixing hot resin = a bubble party. 

Common Summer Resin Problems (And How to Fix Them)

The takeaway? Working with resin in summer isn't impossible. It just takes a little more finesse. Heat and humidity throw curveballs, but if you're prepared, your projects can still turn out smooth, strong, and crystal clear. So get your gear prepped, plan those early morning pours, and embrace the slower, cooler way to create. Your projects will most definitely thank you!