CSLB C-33 Painting & DecoratingCoating ApplicationEasy
A painting crew is applying a two-component epoxy coating to a concrete floor in a commercial kitchen. The product data sheet specifies a mixing ratio of 4:1 by volume (Part A:Part B) and a pot life of 30 minutes at 75°F (24°C). If the crew mixes a 5-gallon batch, what is the maximum amount of time they have to apply the coating before it begins to harden and become unusable, assuming the temperature is constant?
- A30 minutes
- B45 minutes
- C15 minutes
- D60 minutes
Show answer & explanationAnswer & explanation
Correct answer: A. 30 minutes
The pot life of a two-component coating is the maximum amount of time after mixing that the material can be successfully applied. Regardless of the batch size, the pot life remains constant for a given temperature, as it refers to the chemical reaction rate once components are combined.
Why the other options are wrong
- B. This exceeds the specified pot life; the material would likely be unusable.
- C. This is half the specified pot life; batch size does not shorten pot life.
- D. This significantly exceeds the specified pot life; the material would be unusable.
Pot Life
The period of time after mixing multi-component coatings during which the material remains liquid enough to be applied effectively.
- Determined by chemical reaction rate, not batch size.
- Affected by temperature (higher temp = shorter pot life).
- Once pot life expires, material becomes too viscous or hardens.
Memory trick: Mix it, Use it, Lose it: Pot Life's the Limit.