What factors affect epoxy cure?

Individual resin systems are formulated to have an appropriate reactivity level for their end application. However, other factors play a role in how an epoxy cures. These factors are listed below:

• Mix ratio – Follow the mix ratio closely. Keep in mind volume and weight ratios are different. Inaccurate mixing is a common cause of cure-related issues.
  
  
• Inadequate mixing – Mix the product for the recommended duration. Make sure to scrape the sides and bottom of the container during mixing. Ensure product is clear and streak free before use. Do not scrape the container when pouring. Unmixed resin can result in soft or tacky areas of uncured resin on your project.
  
  
• Ambient conditions – Resin will cure faster in warmer conditions and slower in cooler conditions. At the extreme, working in areas that are too warm or too cold can result in overheating or failure to cure, respectively. Follow the recommendations for working temperatures in the product’s Technical Data Sheet.
  
  
• Temperature of your resin and hardener – Similar to ambient temperature, warmer products will react more quickly than colder products.
  
  
• Project size or volume – Larger or higher volume projects will generate more heat and will cure faster. These projects have the potential to overheat and should be monitored during cure. Lower volume projects will be slower to cure.
  
  
• Ability of your project setup to shed heat – Due to the resin system’s chemistry, it will generate a certain amount of heat to complete the cure. These formulations are tailored to cure as fast as possible while avoiding overheating. The ability to shed heat is related to the surface area of the project relative to the volume of resin used. Additionally, the mold or mold material will insulate the curing resin and may play a role in overheating.