When can I pour the second layer?

In cases where you want to make layered casting, you need to wait for the underlying layer to cure for a while. After the first drying time, which is referred to as touch drying, the application of the second layer can be started. This time varies according to the epoxy type and ambient temperature. The best method to determine the duration is to touch the product surface. If you do not feel sticky when you touch the surface with your fingertip, you can pour the second layer.

Attention please: Dust etc. on the epoxy surface in layered castings. Take care to protect it from external factors.

How long does it take for epoxy to turn yellow?

In the vast majority of epoxy systems, the process results in yellowing. Here, the yellowing time and the amount of yellowing vary according to the preferred epoxy type. Resin Slim Extra and Resin Mass are the best resins produced in this direction.

The main factor causing yellowing is sun rays, but the sun is not the only reason for yellowing. The waiting time of the epoxy in the package, the heat generated during its curing, the physical and chemical effects in the environment where the epoxy is cured are also side factors of yellowing. Unfortunately, there are many determining effects that prevent us from placing a clear expression on this period.

In order for your epoxies to remain transparent for a long time, you should first choose epoxy types that are resistant to yellowing such as Resini Mass and Resini Slim Extra, then you should protect your product from direct sunlight, limit chemical effects and not expose it to high temperatures.

Is epoxy heat resistant?

Epoxy systems have different heat resistance resistances that vary according to their types. These resistors vary from 50 C to 170 C according to the properties of the products. You can see the heat resistance of the product you choose by looking at its features. In order for epoxy systems to have full mechanical and chemical properties, they must have completed the final drying period of 7 days at 24 °C room temperature. Curing at low temperature also reduces the heat resistance of the epoxy system. Likewise, raising the temperature during curing will contribute positively to the heat resistance.

In case the epoxy systems are exposed to a temperature higher than the heat resistance value; The system will lose hardness and temporary softening will occur. The softening state disappears when the product returns to normal room temperature and the system returns to its former hardness.

What is the shelf life? How long can epoxy stay in the bottle?

As long as epoxy resins and epoxy hardeners, which are components in epoxy systems, are not mixed with each other, drying and hardening do not occur. Products stored in closed packages in accordance with storage conditions can wait without losing their properties. 

• Hardeners that are left in their packaging for a long time may cause yellowing inside the container. This does not significantly change other performance data other than discoloration of the epoxy hardener. It does not prevent use.

• Crystallization problem may occur in resins that are kept in their packaging for a long time due to exposure to cold air (below 10 C) depending on climate changes or storage conditions. Crystallized resins can be restored to their original state by heating. This process does not change the performance data of the epoxy resin. It does not hinder use. For detailed information about crystallization, you can review our article titled  Crystallization of Epoxy Resin .

Why do bubbles form in epoxy?

There are basically two types of internal air bubbles in epoxy systems. The first is the bubbles caused by the air entering the system during mixing, and the other is the bubbles caused by the gas formed during the reaction of the resin and hardener. Apart from internal reasons, the physical conditions and chemical effects of other components with which epoxies are used may also cause external air bubble formation.

Hava kabarcıkları ve baloncuk oluşumunu engellemek veya minimum seviyeye indirmek için aşağıdaki hususlara dikkat ediniz. 

• Do not mix at very high speed.

• Observe the maximum thickness rule for the epoxy resin type you are using. Do not exceed the specified application thickness. 
• Using a vacuum machine eliminates the possibility of internal air bubbles to a great extent. 
• Overheating the resin that needs to dry at room temperature or in extremely hot environments such as an oven. drying may cause air bubble drying caused by the sudden reaction. (Except for oven-drying epoxy resins produced for this purpose.)
• Do not use coating type resins in casting type works.
• Do not use casting type resins whose consistency has thickened due to the cold environment
  without normalizing their consistency. Check out our article titled “My Resin Has Condensed”.

• Bubbles may come out of the object to be placed in the epoxy system. Cast by considering the possibility of air formation in the cavities on the object. For example, while epoxy penetrates into the air spaces in the wood, bubbles can come out of these. If necessary, perform a two-stage casting.
• Bubbles form on absorbent surfaces due to the impregnation effect of epoxy. Wood, concrete etc. Do not pour or coat the absorbent surfaces without priming. 
• Foaming and blistering may occur due to the reaction of damp surfaces and/or water mixing with the epoxy. Do not apply directly to damp surfaces or objects. (Except for moisture-tolerant epoxy systems produced for this purpose.)
• Do not use water-based paints as colorants. 
• Choosing products, environments and equipment are extremely important for a clean and glassy casting.

Some parts of the epoxy have hardened, some parts are still liquid. Why might it have happened?

Epoxy systems are systems that dry with the combination reaction of epoxy resin and epoxy hardener. In order for this reaction to start, the resin and hardener must come together, and this meeting starts the reaction process, and the homogeneous mixing of the products ends the process successfully and the epoxy drying takes place. 

The case of drying in partial areas or not in partial areas is completely related to the issue of mixing the system. For details to be considered in this regard, you can review our article titled “How to Make an Epoxy Mixture”. 

How to mix epoxy?

Epoksi reçine ve sertleştirici karışımı nasıl yapılmalıdır? En doğru epoksi karışım şekli nasıldır?

The epoxy did not cure (did not dry, did not cure, did not freeze). What is the reason?

Drying in epoxy systems occurs in two different ways between coating types and casting types. In coating type epoxy systems, the drying reaction starts and ends homogeneously. In casting types, on the other hand, drying starts locally and ends homogeneously. In other words, in an epoxy casting application of equal thickness, drying starts from the middle of the dense epoxy region and moves towards the edges. In both types, the final hardness is the same in all areas of the epoxy of equal thickness. Only the time to reach this rank will change. 

When producing epoxy types, it can be produced in different hardnesses, this hardness level can be in the range of 10-95 in terms of Shore D measure.  The hardness values ​​of epoxies are valid up to the maximum temperature resistance level that the epoxy product will reach. A temperature effect on the heat resistance level of a product made of epoxy changes the hardness of the product. 

For example: An epoxy product with a heat resistance of 65 C shows 85 Shore D hardness at 25 C room temperature, while a temperature increase to 80 C may cause the hardness to regress to 60-65 levels. 

Evaluate the following items in light of this information.

If your epoxy is partially cured and partially liquid remains;

There is a problem with the mixture. Mixing is an important step in epoxy use. Make sure that you have done the details about the mixture correctly. See our article titled “How to Make an Epoxy Mixture”.

If your epoxy is partially cured and partially flexible; 

1- It may not be homogeneous.

2- There may be a difference in thickness between the hardened area and the flexible area. Thick surfaces dry early, thin surfaces late. 

3- You may have made an early decision. Your drying process may be in progress. In addition to the late drying of especially thick cast epoxies, the use of the product in low thickness will cause it to dry later than normal. In addition, the time specified as the demoulding time corresponds to the initial time of mechanical hardness, not the final hardening time. It is a specified time for the mold to be emptied and prepared for new casting. 

If the drying is equal in the whole area but the hardness is very insufficient; 

1- Check the hardness value of the epoxy type you have chosen. The product has hardened as it should be, but this value may not be enough for your expectations. In this case, you can work with a different type of epoxy that can dry harder.

2- Check the final hardening time of the type you have chosen. Final hardening is completed in 7-14 days at 25°C room temperature. Wait for this period to complete.

3- Thin casting can be made with thick casting type resin. This may delay the final hardness and you may not even reach the final hardness level at all. For solution, a second layer of thin type resin can be coated on the product.

4- The system may have been in a very cold environment. Epoxies must reach a certain peak temperature value during the reaction. Since the thickness and/or the ambient temperature is too low will prevent the formation of the peak temperature, the final hardness may be delayed and you may not even reach the final hardness level at all.

5- Mixing ratio may not be set correctly. Mixing ratios differ according to epoxy types. This information is available on the label and user manual of the product you are using, please check. You can also get calculation support by clicking the “How Much Epoxy Should I Use” link for mixing ratio.

6- Mixing ratio should be calculated by weight and precision scales should be used when adjusting the mixture. The measurement that should be made by weight with the balance is by eye or glass, syringe, etc. should not be done with volume containers. Due to the negative effect of this situation, your epoxy may not dry completely. “With what to measure the mixing ratio