I have been following Chris Chapmen on U tube and I am sold on Acrylics. I have used them in the past for details and small parts but never sprayed it.
Anyway I have 52 bottles that were over 15 years old. I had them in a box stored in the basement. I took them down and out to the garage. I removed the caps scraped off the dry paint. I found that the paint had separated and the pigment was on the bottom and a glue like substance was on the top. I made a mixer for my Dremel tool and started to stir them. What I found was after about 1.5 hrs I had 51 bottles ready to go. Only one bottle did not survive the years.
I know that because I was able to rejuvenate this paint is because it was stored in a cool place.
I would recommend storing Acrylics in a cool area. 15+ years and all is good
Now I just have to get up the nerve to spray my first body.
Just thought you might be interested!