How long does epoxy take to cure?
Five-minute epoxies set quickly but still need hours to reach full strength, and standard epoxies can take a day or more. Cold slows curing. For safety-critical repairs, elapsed time alone is never proof the bond is ready.
Quick answerIt depends on the exact product. The manufacturers' stated times we track:
- Set / hardened: from 5–7 minutes (Loctite Instant Mix 5 Minute Epoxy) to 4–6 hours (J-B Weld Original Cold Weld Epoxy) across 8 products.
- Full cure: from 1 hour (J-B Weld WaterWeld Epoxy Putty) to 15 hours to 1 day (J-B Weld Original Cold Weld Epoxy) across 8 products.
Find your product, then start a countdown with your exact application time:
| Product | Set | Full cure |
|---|---|---|
| J-B Weld ClearWeld Quick-Setting Epoxy Syringe · US | 5 minutes | 1 hour |
| J-B Weld SteelStik Epoxy Putty Stick Steel-reinforced putty · US | 5 minutes | 1 hour |
| Loctite Epoxy Metal/Concrete Two-part (gray) · US | 5–12 minutes | 1 day |
| Loctite Epoxy Quick Set Two-part (amber) · US | 5 minutes | 1 day |
| Loctite Instant Mix 5 Minute Epoxy Two-part (self-mixing syringe) · US | 5–7 minutes | 1 day |
| J-B Weld WaterWeld Epoxy Putty Hand-mix putty stick · US | 15–25 minutes | 1 hour |
| Loctite Epoxy MARINE Two-part (white) · US | 2 hours to 2 hours 30 minutes | 1 day |
| J-B Weld Original Cold Weld Epoxy Two-part steel-reinforced (1:1) · US | 4–6 hours | 15 hours to 1 day |
Times are the manufacturer’s stated figures under the manufacturer’s conditions. Your product may differ by formula or region. Products are sorted by the first stated time; nothing on this page is sponsored.
Planning information only. Actual results depend on preparation, thickness, ventilation, temperature, humidity, mixing and substrate.