Besides disposal, can Krystal CV after the eight hour pot life expires be used up by adding/mixing small amounts with freshly catalyzed CV? This would be applied to concealed areas only. Would the CV still dry/cure but retain a different hardness?
From contributor R:
Sure can. I go up to a 50/50 mix.
When you add catalyst to a finish you start a chemical process; kind of like adding some baking soda to a glass of vinegar. As the baking soda is absorbed by the vinegar two things happen. First the liquid bubbles and foams as a response to the chemical interaction and second depending on how much baking soda you put in it reduces or neutralizes the acid content of the vinegar. You could add more baking soda, but you don’t get much, if any foaming because the vinegar is no longer a strong acid. If you mix a new batch and pour it into the fizzed out first batch the neutralized vinegar in the first batch will dilute the acid content of the new vinegar thus reducing the overall fizz production of the second batch.
Catalyzed finishes are pretty much the same. At the end of the pot life the chemical reaction is pretty much complete. If you add more catalyst it has nothing to react with. If you add freshly catalyzed material the old finish is just going to reduce the effectiveness of the catalyst on the new finish.
The next morning you add additional catalyst for the amount of virgin material you added the day before. This is an easy way to extend the pot life of conversion varnish. Finishers have been using this method for years and it has been way for small shops to save catalyzed material (not to mention the benefit of not have to dispose of hazardous waste).