Epoxy Installation Terminology
Epoxy.com technical support staff gets asked a lot about the terminology that
the epoxy industry thow around . 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.
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, 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 a 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's 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 - Epoxy.com
Technical Support Director
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