Epoxy.com technical support staff gets asked a lot about epoxy terminology. This page deals with the terms associated with epoxy installation times. Specifically “Epoxy Pot Life” sometimes called the epoxy’s “Working Time“, “Tack Free Time“, “Initial Cure”, and “Final Cure” sometimes called the epoxy’s “Full Chemical Cure“. Keep in mind that all of the information below assumes that the epoxy has been properly measured and mix. The information is specificall based on Epoxy.com Products, but is typically true about many 100% solids epoxies.
Epoxy Pot Life aka Working Time
The “Pot Life” of epoxy is the time that it takes for it to start gelling in the in the mix vessel (typically a bucket). One important thing to remember is that this is done by a standard which is 200 grams of the material at a given temperature typically 70° F or 77° F. So remember that the bigger you make the batch of Epoxy.com resin, the faster the batch will set. See the Epoxy Pot Life Page for more details.
Epoxy Tack Free Time
The “Tack Free Time” of the epoxy is pretty much just what it sounds like. It is the time that the epoxy is no longer sticky to the touch. When the epoxy is “Tack Free” it can be handle or even walked on if necessary, but you will want to be careful because the epoxy will be very vulnerable to scratching right after it becomes “Tack Free”. The “Tack Free Time” given on the product’s Epoxy.com technical data sheet is also at a specific temperature, typically 77°F.
Epoxy Initial Cure Time
The “Initial Cure” is not the same as “Tack Free“. Typically “Initial Cure” is about twice as long as the Tack Free Time. Most epoxies have about 80% of the epoxy’s final cure at “Initial Cure“. After the Epoxy’s “Initial Cure” the epoxy is still vulnerable to scratching, but typically strong enough that these scratching will be strictly esthetic and not structural. In cases where time permits and esthetics are essential you may want to wait 1.5 to 2 times the “Initial Cure” of the epoxy before you allow heavy traffic or rougher handling. The primary outside force that can effect this time is temperature. The epoxy’s “Initial Cure” time assumes the temperature indicated on the technical data sheet, or 77° F. if not otherwise specified.
Final Cure aka “Full Chemical Cure”
When the epoxy has reached its “Final Cure” it has achieved the strengths indicated on the Epoxy.com technical data sheet. It also means that the epoxy has reached its full water resistance and full chemical resistance. This time also is also effected by temperature, similar to all the other times listed above. One interesting note is that “Final Cure” when the epoxy is 99% cured. Epoxy will continue to harden for as much as a year. So the “Final Cure” for epoxy is like the “28 day” cure on concrete. It is typically said that the concrete is fully cured in 28 days. In fact concrete will under the right conditions continue to cure for up to 100 years.
For more information email me at
norm@epoxy.com or visit Epoxy.com “Where to Start” Page for more information.
Norm Lambert
President & Director of Technical Support
Epoxy Systems, Inc Florida & Vermont USA
Available by Phone M-F 9AM-4PM Eastern Time (6 AM – 1 PM Pacific Time)
352-533-2167 (Voice)
352-465-3497 (fax)
norm@epoxy.com
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Posted by Norm Lambert 
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