In epoxy systems, drying takes place in two different ways between coating types and casting types. In coating type epoxy systems, the drying reaction begins 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 in the middle of the dense epoxy area and moves towards the edges. For both types, the final hardness is the same in all areas of the equal thickness epoxy. Only the time to reach this hardness is different.
While producing epoxy types, they can be produced in different hardnesses. This degree of hardness can be in the range of 10-95 in terms of Shore D dimensions. The hardness values of the epoxy 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: While an epoxy product with 65 C heat resistance shows a hardness of 85 Shore D at a room temperature of 25 C, an increase in temperature to 80 C may cause the hardness to decrease to 60-65 levels.
In the light of this information, evaluate the following items.
If the epoxy partially hardened and partially liquid remained
There is a problem with the mixture. Mixing is an important step in using epoxy. Make sure you get the details about the mixture right. See our article titled “How to Make Epoxy Mixture”.
If your epoxies have hardened partially and remained partially flexible
- It may not be homogeneously mixed.
- There may be a difference in thickness between the hardened area and the area remaining flexible. Thick surfaces dry early, thin surfaces dry late.
- You may have made an early decision. Your drying process may be in progress. Especially thick epoxies are structurally delayed drying, in addition to low thickness use of the product will cause later drying than normal. In addition, the time specified as demold time corresponds to the initial time of mechanical hardness, not the final curing time. It is a specified time for the mold to be emptied and prepared for a new casting.
If drying is equal in the whole area but the hardness is very insufficient
- Look at the hardness value of your chosen epoxy type. 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 epoxy type that can dry harder.
- Check the final curing time of your chosen type. Final hardening is completed in 7-14 days at 25 ° C room temperature. Wait for this period to complete.
- It can be made of fine casting with thick casting type resin. This can delay the final hardness and you may not even reach the final hardness level at all. For solution, a second layer of thin resin can be applied on the product.
- The system may have remained in an extremely cold environment. Epoxies must reach a certain peak temperature during the reaction. Since the thickness is too low and / or the ambient temperature is too low, the final hardness may be delayed and you may not even reach the final hardness level at all, as this will prevent the formation of peak temperature.
- Mixing ratio may not be set correctly. Mixing ratios vary according to epoxy types. Please check that this information is available on the label of the product you use and in the user manual. In addition, you can get calculation support by clicking the “How Much Epoxy Should I Use” link regarding the mixing ratio.
- The mixing ratio should be calculated by weight and precise scales should be used when adjusting the mixture. The scaling to be made by weight with the balance is an eye decision or glass, syringe, etc. It should not be done with volume containers. Your epoxies may not dry completely due to the negative effect of this situation. Check out our article titled “What should I measure the mixture ratio?”
- Make sure the balance you use to prepare the mixture weighs correctly. Check out our article titled “I have to use precision scales”.
- It can prevent final hardening of pigments included in the epoxy mixture. Check out our article titled “How much should I use epoxy pigment?”
- Any substance or object you add to the epoxy system may have adversely affected the curing reaction. Check the compatibility of the materials you add to the epoxy with the epoxy and use it after making sure.
When purchasing epoxy, try to choose the product that best suits your expectations and purpose. While working with the product you have chosen, take maximum care to comply with usage details and environmental conditions.