I have heard a lot of different stories about reusing solder paste. I take what is left on the screener at the end of the day (yes i try to watch the amounts that are put down)and transfer it to a clean solder paste jar. I would like to hear any inputs on the good or bad of this practice. Thank You. Bob Merriam
Run a test, but in our experience, yes you can reuse the paste. We ran tests on paste that was left on the stencil at the end of second shift, we put the paste back on the stencil the next day on first shift with no problems. You definitely want to put it in a container to prevent moisture absorption. You should also knead the paste to be on the safe side.
Yes You can reuse solder paste, you simply don't put pback the use solder paste and the new one in the same jar, you don't refrigerate the old solder paste again. And before you begin to use the old solder paste be sure to mix it well.