Epoxy Cure Time Calculator
Resin labels list cure times at about 72 °F (22 °C). Enter the times from your label and the temperature of your room to see how long your pour will really take.
At your temperature
| Working time | – |
| Demold / touch dry | – |
| Full cure | – |
Next steps
Check your mix ratioPlan a deep pour in layersCure time by temperature chartHow to use this calculator
- Find the working time, demold (or tack-free) time and full cure time on your resin label or data sheet.
- Enter them, with the temperature the label is based on. Or tap a typical product to start.
- Enter the temperature of the room where the resin will cure.
- Plan your pour around the adjusted times, and keep the room at that temperature until it has cured.
How the calculation works
Epoxy cures by a chemical reaction, and like most reactions it runs faster when warm. A common rule of thumb from epoxy makers is that every 18 °F (10 °C) change in temperature halves or doubles the cure time:
- Adjusted time = label time × 2(label temperature − room temperature) ÷ 18 °F
This is an estimate. Thick pours make their own heat and cure faster in the middle, and thin coats cure slower. Your product's data sheet is always the final word.
Cure time by temperature
For a resin rated 24 hours to demold and 72 hours to full cure at 72 °F (22 °C):
| Room | Demold | Full cure |
|---|---|---|
| 60 °F (16 °C) | 38.1 h | 4.8 days |
| 65 °F (18 °C) | 31.4 h | 3.9 days |
| 72 °F (22 °C) | 24 h | 3 days |
| 80 °F (27 °C) | 17.6 h | 2.2 days |
| 90 °F (32 °C) | 12 h | 36 h |
Tips for curing in cold or hot weather
- Warm the bottles in a tub of warm water before mixing. Warm resin releases bubbles more easily.
- Keep the room warm for the whole cure, including overnight, not just while you pour.
- In hot weather, mix smaller batches and pour soon, because the working time gets much shorter.
- Do not use a hair dryer on uncured resin; it blows dust and can create ripples.
Frequently asked questions
How does temperature affect epoxy cure time?
Warmth speeds up the reaction. As a rule of thumb, every 18 °F (10 °C) warmer cuts the cure time roughly in half, and every 18 °F colder roughly doubles it. Your product data sheet always takes priority.
How long does epoxy take to cure at 60 °F?
About 38.1 h to the demold stage and 4.8 days to full cure, for a resin rated 24 hours and 72 hours at 72 °F. Below about 65 °F many epoxies cure poorly and stay cloudy or soft, so warm the room instead of waiting.
What is the difference between pot life, demold time and full cure?
Pot life (working time) is how long the mixed resin stays pourable in the cup. Demold or tack-free time is when you can unmold or touch it. Full cure is when it reaches full hardness and heat resistance, usually several days.
Can I speed up epoxy curing?
Keep the room and the resin warm, around 75–80 °F (24–27 °C). A space heater or a warm box helps. Do not add extra hardener; the wrong ratio stops a proper cure.
Why is my resin still sticky after 24 hours?
The most common causes are a cold room, an incorrect ratio, or not mixing long enough. If the room was cold, warm it and wait another day. If the ratio was wrong, the soft spots will not cure and need to be scraped off and repoured.