Are we talking about the rosin paste or the solder/rosin mix that is sold in syringes or tiny, thumb sized cntainers?
Thanks for bringing that up. I didn't even think of the rosin paste. I, too, have had that sitting around for many years with no apparent degradation. What I was asking about was the rosin/solder used for surface mount work. I've got several syringes of it lying around that I haven't used in six or seven years and wondering if they're worth trying to save. I probably ought to dig them out and see if I can even get the plunger out of the barrel of the syringe. That may answer the question right there. I've got several surface mount projects waiting to be tackled and I want to use solder that will make reliable joints but I really don't want to spend money for more containers that will only be partially used and then sit around until they deteriorate.
Guess its time to find what I've got left and see what condition its in.