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 .