A friend asked me to do some turning for him. I hadn't turned for a while. I turned a test piece and normally for something like this I use boiled linseed oil to pop the grain, followed by a couple coats of de-waxed shellac and finally a couple coats of Deft brushing lacquer.
I turned a couple test pieces and with my finishing regimen wasn't getting the results I typically see. My can of brushing lacquer is probably 7-9 years old. So, on a suspicion, last week I bought a new can of Deft. Today, I dumped the old stuff into the can and placed it outside with the can open to allow it to evaporate so I can place it in the trash. While I was outside, using lacquer thinner,I cleaned the jar with the brush lid so I could reuse it. Within in seconds.....maybe a minute at the most....the lacquer in that can became clouded. I was shocked how fast that happened. I had read that moisture can cause lacquer to cloud but I saw it today.
Not sure if brushing lacquer has a shelf life but after opening and using the new can, I was able to obtain the results I did historically.
It's been several years since I turned. It's been that long or longer since I used this finishing regimen.