Finishing calculator
Paint Pot Life Calculator
Race the batch against the paint's own clock. Enter the TDS pot life, the batch mixed, the real spray rate and a safety allowance.
What this calculator does
- Usable minutes in a mixed batch, the margin before it gels, and the largest pot worth mixing at this rate.
Formula used
- Usable pot life = TDS pot life ÷ (1 + safety allowance)
- Time to spray the batch = batch mixed ÷ spray consumption rate
- Margin before the batch gels = usable pot life − time to spray
- Largest batch worth mixing = spray rate × usable pot life
Inputs explained
- TDS Pot Life at Shop Temperature: Supplier's working time at your shop temperature, from the TDS.
- Batch Mixed: Everything in the pot once catalyzed: base, hardener and reducer.
- Spray Consumption Rate: Gallons consumed per wall-clock minute, pauses included.
- Pot Life Safety Allowance: Derate for warm shops and the degrading tail of the window.
How to use the result
- Best suited to sizing the mix so the last gallon sprays, setting a maximum batch on the bench card, checking a fast hardener against a slow job.
- Temperature effects enter through the pot-life figure, not a model. Induction time on some epoxies must be netted from the TDS figure. Metered plural-component equipment has no batch pot life.
Current U.S. benchmarks
- Industrial electricity averages 9.77 cents per kWh across the U.S. (EIA, Jul 2026), up 4.7% from a year earlier. Energy-intensive steps carry this directly into unit cost.
- The producer price index for industrial chemicals stands at 336.006 (BLS, Aug 2026), up 13.3% from a year earlier. Quotes priced off last quarter's material cost miss this move.
- The U.S. has 14,543 chemical manufacturing establishments employing about 911,245 workers (Census County Business Patterns, 2023).
Common questions
- How do I calculate usable pot life? Divide the TDS pot life by one plus the safety allowance: 45 minutes with a 10% allowance gives 40.9 usable minutes. The allowance trims the degraded tail where viscosity has climbed.
- How much paint can I mix at once? Spray rate × usable pot life: at 0.12 gal/min and 40.9 usable minutes, 4.9 gallons is the ceiling. Anything more is mixed for the drain, and the ceiling shrinks with a faster hardener.
- Does pot life depend on how fast I spray? No. Pot life is the chemistry's clock from the data sheet; spraying faster lets a bigger batch beat it but does not lengthen it. The old page derived the window from consumption, backward.
- How does temperature change pot life? Strongly and one way: reaction rate roughly doubles per 15 to 20 °F, so 45 minutes at 70 °F can be near 20 at 90 °F. Use the figure for the pot's real temperature.
Last reviewed 2026-10-01.