Solution to epoxy problems

Does your epoxy stay soft or sticky? Do you have a greasy coating on your artwork or do you suffer from air bubbles? In this article, we give the solution to some common problems that can occur while working with epoxy. We tell something about the cause of the problem and offer you a solution.

Is your problem not listed or do you have any questions as a result of this article? Feel free to contact our specialists, we will be happy to help! In the technical documentation of our products, you will also often find a troubleshooter with solutions for problems that may occur with that product.

1. The epoxy does not harden

After you have processed the epoxy, it takes several hours before it starts to harden. It can happen that the epoxy does not harden at all. 

Cause:

No hardener has been added. Epoxy resins always consist of two components: a base component and a hardener. Mixing both components in the right ratio releases heat that will cure the epoxy. Therefore, if you do not add a hardener to the base, the resin will remain liquid and will not cure.

Solution:

Unfortunately, there is no other option but to remove the epoxy completely. The best way to remove epoxy is with cleaning wipes, acetone and possibly vinegar. You can possibly use a hair dryer or scraper to remove the epoxy. After the surface is clean again, you can reapply epoxy mixed with the right amount of hardener.

2. The epoxy remains soft

If your epoxy does not cure completely, it will remain soft and sticky. Sticky epoxy can be caused by a number of things:

Cause 1:

First of all, the epoxy may not have cured yet. Curing of most epoxy takes about 12-24 hours. However, the curing time of epoxy is greatly affected by temperature. The lower the temperature, the longer the curing process takes. So bear in mind that epoxy sometimes takes a bit longer to cure and may remain sticky for a bit longer.

Solution:

Give the epoxy a bit more time to fully cure or ensure a higher temperature during curing. Is the epoxy still not cured after several days? Then it probably has to do with the cause below.

Cause 2:

Sticky epoxy can in fact be caused by using an incorrect mixing ratio. When making epoxy, pay close attention to the mixing ratio. If you do not follow this mixing ratio, the epoxy will also not cure properly. You can always find the mixing ratio on the hardener's packaging.

Solution:

Always use a scale to weigh out the right amounts of resin and hardener and try to keep the ratio as accurate as possible.

3. The epoxy has soft or wet spots

Do some parts of your epoxy cure well but other parts remain soft, sticky or soft? This problem is somewhat similar to problem 2 but often has a different cause.

Cause:

The cause of this problem lies in the mixing of both components. To activate the chemical reaction optimally, it is important that both components are also mixed well with each other. If you don't mix enough, the epoxy will remain soft or sticky.

Solution:

The solution to this problem is quite simple: mix well! We recommend always using the two-cup mixing method when mixing. This involves mixing the epoxy first in the 1st mixing cup. Mix for about 3 minutes and then pour the epoxy into a new mixing cup. Mix again for several minutes before handling the epoxy. Also scrape well along the sides and bottom of the mixing cup. This way, your epoxy will be optimally mixed.

4. The epoxy resin is cloudy

Have the contents of your bottles of epoxy become cloudy or hard? If so, your epoxy has probably crystallised.

Cause:

Crystallisation can occur due to cold shock or storage in cold temperatures. The cold creates crystals in the epoxy resin.

Solution:

Crystallisation is fortunately easy to remedy. Heat the epoxy in the container to about 40-50 degrees. Open the cap a turn before heating to prevent pressure build-up. Close the bottles tightly again after heating and shake well. After cooling, the epoxy will be clear and usable again. Note: do not process crystallised epoxy. Moreover, always store epoxy in a dark and frost-free environment.

5. The epoxy cracked after curing

A few hours after pouring epoxy, you take a peek to check that everything is going according to plan. To your horror, you see that there is an ugly crack in the surface. Bummer! Epoxy cracking has a plausible cause.

Cause:

If you pour epoxy too thick in an environment that is too hot, the chemical reaction will start too quickly. As a result, the epoxy will get far too hot and this will result in an ugly, yellow and cracked surface.

Solution:

You can avoid this problem by casting thin layers and casting at lower temperatures. If necessary, provide heat dissipation by installing fans or installing cooling. Despite the crack in your epoxy, you may be able to make something really beautiful out of this. Be creative! ;-)

6. The surface has a greasy layer (amine blush)

Does it look like there is a greasy layer over your epoxy surface? If so, you could well be suffering from "amine blush".

Cause:

Amine blush is a reaction between moisture from the air and the hardener in epoxy. So if the humidity in the room is too high or the temperature drops too quickly, the moisture will start to react with the epoxy. Amine blush results in a wrinkled snake skin that looks greasy. It doesn't look very pretty, but fortunately there are several ways to prevent amine blush or fix it during curing.

Solution:

You can prevent amine blush by keeping the humidity of the room low. Using heat mats, heat lamps, radiant heaters or a food dryer, you can heat the room or your work well. With a thermometer and hygrometer, you can measure the humidity in the room and can use this to estimate whether it is wise to pour epoxy. Do you find out during curing that you suffer from amine blush? Then you can still solve this! As long as the epoxy has not yet cured, you can gently heat the epoxy with a heat gun or hair dryer. By brushing the surface with the heat gun, you will see that it becomes smooth again (watch the video on amine blush here). Be careful not to overheat the surface, as you will burn the epoxy.

Read more about amine blush here.

7. The epoxy starts smoking (flash cure)

Does your epoxy suddenly start smoking heavily during processing and does the mixing cup heat up quickly? Then you are suffering from "flash cure".

Cause:

As you probably already know, epoxy cures by a chemical reaction between the resin and hardener. This reaction needs and produces heat. If the epoxy produces more heat than it can dissipate, a so-called "flash cure" occurs. The curing process gets faster and faster and more heat is produced. This causes the epoxy to get so hot that it starts to smoke.

Solution:

Unfortunately, if you suffer from flash cure, there is little more you can do about this. Put your epoxy quietly outside until it has cooled down completely. Make sure you put your mixing cup out of reach of children and pets.

Preventing flash cure?

Use these tips to prevent your epoxy from overheating:

• Make sure the ambient temperature is not too hot (20°C is the recommended temperature).
• Pour in less thick layers.
• Use epoxy that cures more slowly.

8. My epoxy turns white

Does the epoxy turn white during processing? If so, moisture is often the cause.

Cause:

The cause of this problem is often related to moisture. Moisture and epoxy do not mix well, which can cause the epoxy to turn white or not cure properly.

Solution:

Avoid epoxy coming into contact with moisture. Keep room humidity as low as possible. Are you working with dried products such as flowers, fruit, stuffed animals, etc.? Then make sure these are thoroughly dry and use silica gel to draw the moisture out of the product. Also, if you use epoxy in combination with wood, it is important to let the wood dry very well and seal it with epoxy.

More information on epoxy?

Do you have more questions about epoxy? If so, feel free to contact our specialists. We will be happy to think along with you!