It sets in 4 minutes and cures in 4-6 hours, while J-B Weld sets in 4-6 hours and cures in 15-24 hours. Because it is faster setting, KwikWeld has about two-thirds the strength of J-B Weld; however, they are both strong enough for most projects and repairs.Click to see full answer. In this manner, how long does it take JB Weld to harden?At room temperature, J-B Weld™ sets in 4-6 hours to a dark grey color. A full cure is reached in 15-24 hours. J-B Weld™ has a tensile strength of 5020 PSI and sets to a hard bond overnight. It can withstand temperatures up to 550ºF when fully cured.Beside above, is JB Weld permanent? J-B Weld is The Original Cold Weld two-part epoxy system that provides strong, lasting repairs to metal and multiple surfaces. Mixed at a ratio of 1:1, it forms a permanent bond and can be shaped, tapped, filed, sanded and drilled after curing. It can withstand temperatures up to 550ºF when fully cured. Subsequently, one may also ask, can you make JB Weld dry faster? “DRYING: Allow 4-6 hours for drying before handling. Allow to dry overnight (approximately 15 hours) before putting object to use. J-B WELD works faster if used in a room with a temperature above 50? F. After J-B WELD has cured for six hours, a heat lamp or light bulb placed near the weld will speed drying time.”Is JB Weld stronger than welding?General Principles: Although JB WELD makes an excellent filler—and can even be used to cast small parts, it is not remotely as strong as real metal used this way. Whenever possible, use JB WELD as an adhesive—a very thin layer of JB WELD holding two pieces of metal together.