The Pot Life on the Data Sheet Isn't Your Pot Life

The Wet Edge, No. 004. Short field notes for coating crews.

The pot life on the data sheet was measured at a set temperature with a set amount of material. Your pot on a July afternoon is neither.

Two things move it. The first is heat. Tnemec's Series N69 epoxy lists a pot life of 6 hours at 50°F, 4 hours at 75°F and 1 hour at 100°F. With the 44-700 cold-weather accelerator, those drop to 2 hours, 1 hour and 30 minutes. The second is mass. Mixed epoxy makes its own heat as it cures, and a full kit sitting in a bucket holds that heat and speeds itself up.

Don't stretch it. Data sheets say not to apply past pot life for a reason: the cure is already underway, and thinning a thickening pot doesn't reset the chemistry. It just adds solvent to material that's on its way out.

Some epoxies also call for an induction or stand time after mixing. N69, for example, asks for a 30-minute stand and a restir when it goes onto cool surfaces. Respect that too. It's part of the cure, not a coffee break.

The practical move: in heat, mix smaller kits, keep material out of the sun until you need it, and write the mix time on the pot with a marker. When the clock's up, it's done.

Bottom line

Pot life shrinks with heat and batch size. Mix what the crew can spray in the time you actually have, mark the mix time, and let the rest go.

Further reading: Tnemec Series N69 Hi-Build Epoxoline II; Pot Life vs Spray Life: What's the Difference? (Tnemec).

Talk to a consultant. Questions on a job? Atlantic Coating Consultants supports contractors in PA, NJ, DE, MD, DC, WV and OH with product recommendations, field support and crew training. Call 484-644-5303 or email atlantic@tnemec.com.