Fast Set Epoxies: are great for jobs that have to be done quickly, they are going to have a working time of 3 - 5 minutes and fully cure in less than 30 minutes. However, faster set epoxies are great for general repair work, but are known to be more brittle than the slower set epoxies.
Medium Set Epoxies: These epoxies are designed to give you a few more minutes of working time, 15-30 minutes. Offers good flexibility and shear strength.
Slow Set Epoxies: The most working time at 30 - 45 minutes, these are the most flexible epoxies. Great for delam problems.