How Does Hot Weather Affect Resin?

Although resin prefers warm temperatures over cold, a hot and humid climate can cause curing issues in epoxy resin, and prolonged heat exposure can even affect cured resin. To achieve optimal results, it's best to work with 2 part epoxy resin in a warm, dry environment throughout the curing process. Here are 3 simple tips to help you beat the heat and ensure a successful summertime resin:

  1. Keep your workspace, resin and tools at standard room temperature: The ideal conditions are 75°F (24°C) to 85°F (30°C), and the temperature should remain stable for the first 24 hours.
  2. Ideal humidity is below 50% however you can work in conditions less than 80% humidity.
  3. Cured resin art should not be exposed to high temperatures or direct sunlight for any length of time.

Wondering why temperature is so important? What effect do high temperatures and humidity have on epoxy resin? And what happens to cured resin art in the heat of summer? 

Let's find out .... 

1. Keep your workspace and your resin slightly above standard room temperature:

When the resin and hardener are combined, the curing process generates heat - in fact, you may notice that your resin starts to get warm after it's mixed. The higher the heat, the faster the resin will cure. 

On one hand, a warm room can work to your advantage while your piece is drying, however temperatures above 85°F/30°C can jump start the curing process, causing the resin to get hot very quickly and thicken prematurely.

resin gets hot after mixing

In summer, air conditioning is a good idea to help maintain standard room temperature or just slightly above:  the ideal room temperature is no cooler than 72°F/22°C and no higher than 85°F/30°C.  If air conditioning is not an option and the temperature is above 85°F/30°C, work in the coolest part of your house.

ideal temperature to resin 75-85F or 24-30C

💡TIP: Ensure the resin room stays stable during the entire curing process: 
the first 24 hours of a cure are critical and temperature dips may result in surface imperfections. For example, placing a resined piece to cure in a sunny window may seem ideal, but when the sun goes down, the temperature does too. You may end up with the "orange peel" effect with dimples, waves and other strange imperfections in your resin. 

Luckily, this is an easy fix! 
Learn how to fix surface mistakes in our blog How To Apply A Second Coat.

Just as the temperature of your room can affect cure time, so too can the temperature of epoxy resin: resin and hardener that are too hot can cure prematurely or even instantly after being mixed.  

Preparation is key when it comes to working with resin during hot summer months: make sure your tools and project are prepped and organized so that you can pour immediately after your resin is mixed. Never use resin that has come straight out of a hot car or that was delivered and left out on a hot day: allow your resin and hardener time to come up to room temperature before you plan to pour. Store your opened or unopened bottles out of direct sunlight in a spot where it will stay stable at room temperature.

let resin cool down after being in a hot car before you use it

💡 TIP: Don't forget that if you're applying resin to a surface that can retain heat (like metal) a hot substrate can also accelerate curing and diminish your working time.

metal tray can get hot and cause resin to cure too fast

2. Keep humidity between 50-80% when working with resin: 

The heat of summer often brings along with it high humidity. Humidity refers to the amount of moisture in the air and it can make a big difference in your resin's final result. When moisture is introduced into the mixture, you may end up with amine blush, which is most often characterized by an oily film or a cloudy appearance on the surface layer. This loss of clarity can occur during mixing and pouring or while the piece is curing so it's important to maintain consistent temperature and humidity levels throughout the curing process: suggested humidity should be below 80% and ideally below 50% for optimal results.

Air conditioning can cut humidity but running a dehumidifier the day before you plan to resin can be valuable if you live in a very humid climate. 

💡 TIP:  Read more about moisture and resin in our blog How Does Moisture Affect Epoxy Resin?

humidity can cause resin to turn cloudy

suggested humidity levels for resin below 80% ideal below 50%

3. Do not expose c
ured resin to high temperatures or direct sunlight:

Cured resin art can withstand a certain amount of heat, say, a warm coffee cup on a coaster, for example, but very high temperatures can cause fully cured resin art to temporarily soften. The resin will quickly harden up again once it cools down, but prolonged exposure may cause the resin to shift or distort.

For example, a coaster left in a sunny window may become flexible, but will quickly harden up again once the temperature drops.

resin coaster bends temporarily in heat
resin coaster doesn't bend when cools down

In the case of resin artwork, this flexibility can make the resin vulnerable to denting and damage: care must be taken not to stack up or lean artwork against each other if, say, you're showing your work at an outdoor art festival.  

resin art outdoor festival high temperatures damage resin
stacking resin art can damage resin

⚠️ PLEASE NOTE:  Never leave cured resin art, including tumblers, inside of a hot car during the summer months. In these conditions, the temperature can get exceedingly hot. Gravity may pull the softened resin, causing it to pool or warp irreparably. 

never leave resined tumbler in hot car
temperature too hot for resin in hot car

So remember, for flawless results during the summer months, always use ArtResin as directed and remember these rules of thumb:

  • Keep your workspace, resin and tools ideally between 75°F/24°C - 85°F/30°C and stable for the first 24 hours.
  • Ideal humidity is below 50% however you can work in conditions less than 80% humidity.
  • Cured resin art should not be exposed to high temperatures or direct sunlight for any length of time.


What is the best temperature to store ArtResin epoxy resin?

Opened or unopened, store your ArtResin bottles in a dark spot, out of direct sunlight and in a spot where the temperature will stay stable at room temperature or just slightly below ( 70°F or 20°C ).

perfect resin consistency is like honey


Do you want to know more about ArtResin epoxy resin? Read our guides below:



Hope you found this valuable - please leave any questions or comments below. Let's resin!


ArtResin:  Made For Artists, By Artists.

About the author: Joanne Wright

I'm Joanne, the Marketing Content Writer at ArtResin. Originally from Canada, my home is now Indianapolis, Indiana. My love of all things creative and my entrepreneurial heart means I’ve worn many hats over the years including fashion producer & stylist, retail store owner, t-shirt designer, and even vegan baker! I...