How long does epoxy take to cure? (in a thick pour)
Short answer
up to 7 days
Deep casts hold heat unevenly and need far longer to reach full hardness.
What changes the time
| Condition | Time | Why |
|---|---|---|
| in cold weather | 48-96 hours | Below ~18C the reaction slows sharply; warm the room to speed it up. |
| in a thick pour | up to 7 days | Deep casts hold heat unevenly and need far longer to reach full hardness. |
| with a fast hardener | 6-8 hours | Fast hardeners cut working time but cure much quicker. |
Tips
- Mix the exact ratio by weight — off-ratio epoxy stays tacky forever.
- Keep the room at 22-25C for the most predictable cure.
FAQ
Why is my epoxy still sticky after 24 hours?
Usually an off-ratio mix or a cold room. Warm to ~25C and wait another 24 hours.