Common errors with epoxy

Do you suffer from epoxy that does not harden, remains sticky or does not adhere? In this article we highlight the most common mistakes when working with epoxy. Working with epoxy is not difficult, but it does require accuracy. What should you pay attention to and how do you ensure that your project is a success? In this article you can read the 7 most common mistakes when working with epoxy. Polyester shopping tells you what to do to avoid these mistakes.

Epoxy that does not harden, remains sticky or does not adhere

After mixing the base (resin) and hardener, you may notice that the epoxy does not have the desired effect. You may then notice that the epoxy does not harden and remains tacky. The epoxy resin will also not adhere in some cases. Fortunately, all these problems can be avoided if you do it right. By following our tips you ensure that the epoxy has the properties for optimal operation. Check out the tips and apply them!

1. Not mixing well enough

One of the most common mistakes is not stirring well enough. If you don't stir epoxy well, the epoxy may remain soft or sticky. This can hinder your project. You can easily avoid sticky and soft epoxy by using the two-cup mixing method. In this method, you first mix the epoxy in a mixing cup for about 2 minutes. While doing this, scrape well along the sides and bottom. After two minutes, pour the mixture into a second mixing cup and repeat the process. After this, the epoxy is ready to use. While using the epoxy, you will notice that it is firm and not sticky.

2. Adding too much or too little hardener

What also often happens is that too much or too little hardener is added to the resin. This may be because the components are not accurately weighed or because people think the epoxy will cure faster if more hardener is added. With epoxy, it is important to always keep the mixing ratio right! Otherwise there is a chance that the epoxy will remain soft or sticky. So always use kitchen scales when weighing. 

3. Mixing by volume

All RESION epoxy resins have a mixing ratio based on weight. This mixing ratio is indicated on both the bottle and the product page. Some people make the mistake of mixing by volume instead of weight. As a result, they take 100 millilitres of epoxy with 60 millilitres of hardener, for example, instead of 100 grams of epoxy with 60 grams of hardener. Applying the wrong mixing ratios will often leave the epoxy soft and sticky. Always use kitchen scales for weighing.

Exception: resins from Eli-Chem, such as MasterCastTotalCast and UltraCast do have a ratio based on volume. You can easily measure this in a mixing cup. 

4. Using the wrong mixing ratio

What happens a lot is that when working with epoxy, people keep the wrong mixing ratio with polyester or silicone, for example. The mixing ratio is always stated on the bottle and on the product page. In most cases, you will also receive an e-mail stating the mixing ratios. By keeping to the mixing ratio, you ensure that the epoxy does not remain soft and sticky. The epoxy will also adhere better. 

5. Using water-based pigments

Epoxy and moisture are not friends during the curing process. For example, when water-based acrylic pigments are mixed with epoxy, this can cause very strange things during the curing process. In many cases, the epoxy gets very hot and deforms. So always use pigments specifically for epoxy, such as RESION pigments for epoxyMetalTint pigments or TransTint pigments. Please view all other types of epoxy pigment.

6. Insufficient surface treatment

If the surface is too smooth, "craters" may form during curing. It then appears as if there are all islands in the epoxy. In many cases, this is due to "batting problems". The substrate is so wet that epoxy struggles to wet the substrate. As a result, the epoxy will not adhere to the surface. Fortunately, this can be remedied by coarse sanding the substrate. Should this not be possible, you can also use a special primer to ensure the epoxy adheres to the surface.

7. Casting water-containing objects

Many people like to pour in objects such as flowers, plants or twigs. This often goes well, but sometimes you will find that the epoxy does not cure properly or that unwanted effects occur. This is because many organic materials contain water. The water can be released into the epoxy, causing reactions you might not have expected. As a result, the epoxy may remain soft and sticky or even fail to adhere. So keep in mind that this could happen if you pour in a flower, for example. In the video below, Leen shows how to pour in a flower.

More information?

By applying these tips, you will see that epoxy almost always cures well and is nice and even. The epoxy will not be soft and sticky and will be able to adhere well to the desired surface. At Polyestershoppen, we understand that you have many questions when working with epoxy for the first time. In our information centre, you will therefore find all the expert knowledge you need for working with epoxy. If you have any more questions or would like tips, feel free to contact us. You can reach us by phone, email or chat!

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