Someone Just asked Me – “How Hot Can Epoxy Withstand?”

I instantly giggled to myself. I believe they really meant to ask me “How Much Heat Can Epoxy Withstand“. So let’s look at this.

Hello and welcome my fellow DIYselfers and artists, we hope the information presented in our previous articles has been educational and beneficial to you in creating amazing epoxy resin pieces. As the popularity of epoxy resin grows and the various ways in which it can be used, heat resistant epoxy resin is at the forefront.

There are countless types of epoxies, knowing which ones are heat resistant can be challenging. In this blog, we will be discussing this topic and its effects on resin. Is it heat resistant? How much heat can resin withstand? Can too much heat incite a fire in your resin work and more. We invite you to continue with us on this part of the journey as we venture into another lesson.

Is Epoxy Heat Resistant?

Yes!!! While there are specific standards to be met and understood, your epoxy resin is definitely heat resistant. For a basic DIY epoxy resin small sized project will be able to withstand low heat temperatures between 68-195 degrees Fahrenheit, anything higher and it will begin to deform or soften. The epoxy will lose its glass-like surface and become rubbery.

High temperature/high heat resistant epoxy resin is another type of product and may come in multiple variations depending on your heat range and your preferred branding. Made to withstand temps above 600 degrees Fahrenheit this epoxy is manufactured with fillers like quartz and reinforced with elements like titanium. These have the capabilities, of course, to be used in way harsher environs which allows them to withstand high temperatures.

How much heat can epoxy withstand?

While small projects and home use project epoxies are usually able to withstand heating of one hundred and fifty (150) degrees Fahrenheit to about three hundred (300) degrees Fahrenheit for a short period. High temperature heat resistant epoxy can withstand extreme heat up to six hundred (600) degrees Fahrenheit that are specially formulated with fillers and offer abrasion resistance and high heat curing.

What happens if epoxy gets too hot?

Several things can happen when your epoxy gets hot, which becomes problematic for your project. This may include:

Your cured epoxy may have a crack.
If your resin is filled with bubbles, it may also appear foamy, and can cause your cup to melt or smoke.
After filling the voids and/or removal from the mold, you may notice shrinkage in your casting piece.

What can cause your resin to heat up?

Here are a few reasons that cause your epoxy resin to get too hot:

Reason #1:
Resin kits usually come with instructions on the maximum and minimum amount of resin and hardener to be mixed. If you mix too much at once, too much resin and hardener mixed together produces too much heat too quickly resulting in your resin getting too hot.

Reason #2:
You’ll find suggestions such as heating the resin kit bottles to help reduce bubbles in your resin mix. There is some truth in the statement, however, the extra warmth in heating the resin will jumpstart the resin’s reaction and get your resin mix warmer much sooner than expected causing problems in your work because the resin and hardener was already too warm to work with.

Reason #3:
You may have added something to the resin and hardener that caused it to heat up too quickly. For example, When using paint and other solvent based colours, this can speed up the resin curing reaction and cause the mixture to heat up too quickly. While we encourage you to go wild and get creative because it’s fun to work with resin and to try new things, we don’t always know what the outcome will be.

Reason #4:
You applied too much heat from a heat gun or other tool to remove bubbles. Heating your resin aids in bubbles removal and is one of the fastest and more effective ways, but we should also remember that this heat also adds to the mix’s chemical reaction. As simple as this may be, the heat from these equipment also adds to the heat of the resin’s reaction and may damage your artwork. This is all the more reason to heat on and off.

Reason #5:
You applied too thick a layer. At room temperature, each resin system has a safe pour depth, when this depth is exceeded the amount of heat generated becomes problematic. A chemical reaction takes place that kick starts the resin curing reaction and causes the mixture to heat up too quickly.

How can I prevent resin from getting too hot?

Method #1:
For our artists in the Florida area or more tropical regions such as the Caribbean, or anyone living in a warm climate who suffers from high humidity levels (80s and 90s temperature), it is recommended they cool the space you’re working in or wait till the air temperature drops before pouring epoxy. In this case, you would need to work during the cooler hours of the days, such as early mornings or later nights to prevent your resin from getting too hot.

Method #2:
In all our posts we constantly reiterate the importance of sticking to the manual that comes with your resin kits. In most resin kits, the manufacturers outline the maximum and minimum amount for your mix. The minimum amount ensures enough heat is produced to start resin curing, and the maximum mixing amount ensures that the resin doesn’t heat up too quickly. If you mix too much at once, too much resin and hardener mixed together produces too much heat too quickly resulting in your resin getting too hot. To avoid this scenario, we ask you to stick to the amount recommended to prevent any mishaps in your work.

Method #3:
If the amount of resin you need for your project exceeds the maximum amount recommended, you should mix and pour several batches of resin if necessary keeping in mind if the layer you just poured is hot, that heat will transfer into the next layer. So it would be best to wait several minutes to allow the heat to escape before pouring the next layer.

Method #4:
Some resin takes hours even days to cure. Using a slow curing resin would be best as they generate heat slower and are less likely to encounter problems listed above.

How Do I Heat My Resin?

Now we need to be mindful that a mixture of resin and hardener do have heat existence. Hence the technique may vary dependent on the maximum or minimum combination used. In calm conditions, it is recommended that you use a supplement heat to increase the epoxy’s temperature, which aids in the curing of your project at a faster speed.

To heat your resin art piece, you would need to use a heat gun, butane torch, heated lamp, and other safe options. In heating your project, you need to for short periods. Consistent heating can cause any of the above to happen.

Can Heating Dry My Epoxy Resin Faster?

Heating is a useful medium in drying your epoxy project. While it is recommended to use a lower temperature environment for your work, a higher temperature environment also aids in drying the resin once applied, by heating the room or area your project is in. Every eighteen (18) degrees Fahrenheit increase in temperature cuts the time for resin to cure in half. Another option is if you are working in a warm room you can use a heater or heat lamp to encourage the resin to cure faster.

Increasing the room temperature does speed up the process, but you need to be mindful the mixture has its own heat. Never exceed the room temperature over eight-five (85) degrees Fahrenheit. Remember: Cure time is affected by temperature. Warmer temperature facilitates curing and colder temperatures slows down curing. Your resin will cure 95% within twenty-four (24) hours and 100% in seventy-two (72) hours. We do not recommend heating after the 24 hour timeline as this can cause your project to have cracks.

Heated Epoxy Too Long, Can I Fix It?

Even the most experienced artist makes mistakes, so don’t be too hard on yourself. One common mistake is mixing the epoxy too long that it gets hot, you feel the panic building and find yourself wondering, can it be fixed? It’s possible, but it depends on the error.

The most important thing is to bring the epoxy temperature back to normal. Once the epoxy has stabilized you can focus on your project. If the epoxy was too hot for a long time there will be some issues, the main one is cracking in the epoxy. This happens because one part was cured faster while the other part is hot. Manufacturers of epoxy resin always stress the importance of mixing the right proportions of mixture to get the best results for your work. If you were working on a large project it’s best to mix small batches.

The key is slowing down epoxy’s curing by creating more surface area and exposing more of the mixture to air. Epoxy will build heat unless it is spread into a thin film or quickly poured into a container with more surface area allowing the epoxy’s heat to dissipate.

If you are working on a large project and because work time is shorter with large batches, you should consider a slower curing hardener to extend your work time so the epoxy won’t overheat. Temperature also plays a major factor in resin not curing properly. Never let temperature go under 75 degrees (can go up to 90 degrees) when the temp is warmer the epoxy will react quicker resulting in shorter mixing time and faster cure time.

Can Epoxy Catch Fire?

Remember when we combine resin and hardener a chemical reaction takes place between the mixture that generates heat. When the heat cannot escape, it builds up causing the epoxy to cure faster, because epoxy cures faster at a higher temperature. With the buildup of all this heat it can cause cured epoxy to crack. This uncontrolled heat is called an uncontrolled exothermic reaction or “exotherm”. This uncontrolled heating can cause excessive foam, vapor, and even smoke, that can cause the container it’s in to smoke, melt, and even catch nearby items on fire.

It is unlikely cured epoxy can catch on fire however, if you are working with wood or mold the high temperature can cause it to set on fire so you need to be cautious when working with epoxy.

Is epoxy flammable?

No, it is not flammable. Before use epoxy is considered a flammable liquid. The hardener/cureative is a non flammable liquid. Once mixed together it produces heat, when used in the manner it was designed for (as an adhesive, coating or mold) and fully cured, epoxy is not flammable.

What is High Temperature Epoxy?

High temperature epoxy also referred to as high heat epoxy resin as the name suggests possesses properties that can withstand high temperatures that can be used primarily in adhesive and coatings. In addition to withstanding high temperatures, high heat epoxy also exhibits less potential for corrosion and chemical resistance. This product is specifically formulated for use in large projects and industrial applications.

Why Would You Need Heat Resistant And High-Temperature Epoxy?

Let us face it, some things in life require a harder environment, more heat resistant, something our tiles or soft surfaces cannot handle. Heat resistant epoxy is mainly selected for those environments that require a higher than normal temperature, this may include but is not limited to home or small restaurant kitchens.

Usually used in the industrial platform, high temperature epoxy is specially formulated for large projects such as countertops. Also, high-temperature epoxy is used in places such as mechanical and electrical markets from aircrafts to motor vehicle devices. High temp epoxy needs to be strong and should last long wherever a bonding agent, sealer or coating is needed.

What You Should Know About Using Heat Resistant High-Temperature Epoxy.

We must remember that epoxies are polymer chemicals that cure into a hard surface. It is a durable, chemical resistant bonding agent. Once the compounds are blended you have approximately one hour of work time aka “pot life” so you have to be ready to use it immediately once the ingredients have been combined. If the timeline expires, the mixture can become extremely hot and harden quickly. The best temperature to use epoxy ranges from 64-85 degrees although others believe the optimal temperature is around 72 degrees.

Once the epoxy is cured it can withstand temperatures below zero (0) degrees. Around 140 degrees the epoxy will begin to soften. When the temperature recedes, it will harden again, so if you’re planning on using a surface that comes into constant contact with hot items, then using a high temperature epoxy will ensure that you don’t have to worry about damaging the surface once the epoxy is cured.

This is where we get a bit technical. When epoxy is exposed to higher temperatures, its thermal, mechanical and electrical properties will change. The Tg or glass transition temperature of the epoxy can be affected. This is critical as your epoxy will turn from glass to rubber. So it is important to choose the right epoxy for your project. You will need to use the heat deflection temperature or HDT rather than the Tg method when selecting a high heat epoxy such as a commercial high heat epoxy keeping in mind that these epoxies may require additional heating methods.

There are several benefits of using heat resistant epoxy, these include:

Durability
Strength
Thermal conductivity, and
Flame retardance.

Some also offer UV curability and even super flexibility.

Are High Heat Epoxies Clear when cured?

While heat resistant epoxy is fantastic to use to get that glossy finish, not all will give you that crystal clear finish you desire. Some heat resistant epoxy will give you a yellowish hue. This is dependent on the manufacturer and the brand so be sure to read the instructions and check the packaging before you use the epoxy so you get the right one for your needs.

What Can Reduce The Temperature Resistance?

There are various ways to reduce the temperature resistance of your epoxy. The most crucial view is following the mixture dictated by the manufacturers. Another lesson to our beginners from a previous article outlines the curing process when coloring agents or other items are being mixed in the methods. This is also inclusive of the mixing time, the quantity, and the speed it is removed from the cup/container.

When there are additives in the mix included but not limited to pigment, ink, or other coloring agents, this reduces the temperature resistance. To avoid this, most professionals will add a clear coat on top of the colored mixed epoxy to have adequate heat embedded in drying.

Tips and Tricks For Heat Resistant Epoxy Resin

The leading information that anyone can give is to follow the manufacturer’s instructions on the product being used. As was mentioned, the simplest of deviations may result in an unlikely product or art piece you did not desire. We also advise that you mix the exact amount needed for your project.

Always remember that once your mixture is complete, the clock starts ticking so preparation is vital.
Ensure your work area or table has only what is needed and is of the right height.
Clean your worktable or area with isopropyl alcohol and cloth, getting rid of any unnecessary particles.
Ensure you mix for the required time, and your mixture is consistent.
Always take note of your room or environment temperature, which also aids in your project’s outcome. When the climate is not right (being too hot or cold), your mixture may have a sticky, waxy appearance.
There are a few ways that we suggest getting rid of bubbles from your art piece, which are by using a cocktail stick, butane torch, blow dryer, or heat gun. In utilizing the heating methods, ensure to hold equipment approximately twenty (20) cm from your art piece and avoiding heating too long.
Cure your art piece in a dust-free environment and ensure you blow dust away from the art.
Remember if you added pigments or powders the molecular structure of the resin will be altered. This reduces the heat resistance and non-toxicity. Always finish your project by applying a clear topcoat so you will be able to put hot objects onto it.

FAQs

What temperature does epoxy melt at?

Epoxy does not melt but will burn when additional heat is added. There are many different types of epoxies available on the market with each one having their own heat resistance levels. At 140 degrees epoxy will begin to soften but will re-harden when the temperature is reduced.

Does heat soften epoxy?

Yes, when heat is applied epoxy can soften, to soften epoxy it must be heated beyond its Tg (softening point) and/or curing temperature, when using a heat gun or soldering iron heat small sections at a time so it stays warm enough to soften.

What happens if you heat epoxy?

The constant heating of epoxy can cause condensation and/or contamination. If necessary, warm your epoxy resin by storing it above a heater. Hardener should be maintained at room temperature as heating uncured hardener can cause amberization.

Can you put hot pans on epoxy?

Yes, once fully cured, you can set hot pans, cups, plates and bowls on epoxy. Epoxy is naturally heat resistant. However, never put a hot pan or skillet directly from the stove onto the epoxy. Proper padding or use of a trivet set for your pans will give your epoxy a longer life span.

Is tabletop epoxy heat resistant?

Many tabletop epoxy resins are not high heat resistant with temperature up to 150 degrees Fahrenheit, we discovered Stone Coat Epoxy resin which is heat resistant and can withstand temperatures up to Five hundred (500) degrees Fahrenheit, is eco-friendly and scratch resistant.

Are epoxy tables durable?

Epoxy tables are most definitely durable, compared to polyurethane, epoxy is known for its sturdiness and durability as well as its resistance to moisture. Heat resistant epoxy resin is also durable and provides extra strength and stability.

Will acetone remove cured epoxy?

Acetone is useful in removing cured epoxy on wood and concrete surfaces so it peels easily. To remove epoxy from the skin apply acetone to a cotton bud or paper towel and rub gently onto the area. Acetone is the primary ingredient in nail polish remover. If you’ve just completed a project and the epoxy is still wet, you can use a cloth with some acetone, if it’s already cured, you will need a blowtorch to heat it up and then use a trowel to scrape it off. Be aware that acetone is flammable and should be used in a well ventilated area/space.

What dissolves cured epoxy?

Our professionals will refer varied options for removal of or dissolving cured epoxy, this includes:

Acetone
Alcohol
Vinegar
Lacquer thinner