Yes, the catalyst I mentioned replaces the part B, but I forgot some additional information: it was about $15 a pint, BUT the mix with it is 2 parts color (Part A) to 1 part catalyst, rather than the old 1 to 1 ratio we used to use. So a pint does what a quart used to do. I have used it at this recommended ratio and it works fine.

The info on the Petit thinner is good to know too.

Clair