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I had planned to get cracking with some Royal Lac post catalyzed experiments a year ago, but got distracted by other things. As a result, I had some unopened Royal Lac post cat (purchased in October of 2020) that I wanted to make sure was still good before I used it, so I e-mailed Vijay. Here is his response:

"It should be good. Shelf life is 2 + years and pot life is 8-10 hours. To be sure, make a small batch like 14gm of finish and 2 gym of catalyst. (7:1 ratio). Apply on a scrap piece and it should be pretty much dry by the hour."

So, there you have it. Shelf life is more than 2 years, and you can test it by checking how fast it dries on scrap. If it isn't dry in an hour, don't use it on a workpiece.

I hope this is helpful.

Thanks for this. I'm getting ready to use the quart I ordered last December.

My pleasure, James. Vijay is pretty responsive to these sorts of practical questions. I like to document the answers here, as a handy search reference for all (me included).