How does temperature variation effect epoxy?
For every 18o F, the temperature falls below 77o F, the pot life will double for the mix. The thin film set will come close to a 1.3 increase in time. The exact opposite will occur as temperatures increase above 77o F. Applications which are allowed to cool below the freezing point must be warmed to achieve a full through Cure. In the case of freezing the solid or film must be checked for hardness to insure full, strength has been achieved. Back to top 23. Checking for Hardness – Using the Rule of “Thumb” To quickly check for full hardness, press thumb nail into solid or coating firmly (no indentation should occur). This test is also very helpful when determining if a piece is ready for sanding or machining. Back to top 24. Customizing Cure Times – the blending of Slow and Fast Hardeners The time it takes for an epoxy mixture to change from liquid to solid is the Cure time. There are three phases – 1. open (working) time or wet lay-up time. (liquid) – 2. Initial cure or gel – 3. Final
