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 ensure full strength has been achieved. This test is also very helpful when determining if a piece is ready for sanding or machining. The time it takes for an epoxy mixture to change from liquid to solid is the cure time. The mixture is still liquefied.
Initial cure is reached when the mixture has turned to gel.
Final cure is when the epoxy is now solid. Cure times can be speeded or slowed depending on your needed application by the combining of the Fast and Slow hardeners. This happens because the Slow generally has a lower peak exotherm temperature and the Slow molecules are bulkier, which slows down the whole chemical reaction between the resin and hardener. The cure times are not directly proportional to the amount of hardener used to customize the blend. Smaller batches of epoxy create less heat than larger batches and also have longer working and cure times.