I was using a nice paintbrush with polyurethane and it seems that I set it down then forgot to clean it. I have since run into it and I have a shiny, relativity tough, paintbrush now. Needless to say I do not value these qualities of my paintbrush.
I stuck it in a small container of mineral spirits, as it was the only solvent I have available, and left it for a couple of days and for the most part there was no change. Still a tough brush.
Again I forgot about it and it has since been months.. So there is no doubt the polyurethane has fully cured by now.
Did I doom my paint brush to the garbage or is there something I can still do to save it?