A few years ago a small independent woodshop owner {now closed} was telling me about a trick to saving sandpaper for a drum roller. It was to clean the roll in a bucket with dish washing detergent.
I'm now thinking about this trick since I now have many rolls that others wise be tossed away.
From what I remember he said you soak the paper and then the build up could easily be removed and then you just hang it to dry.
Any thoughts?
Phil