A few weeks back I was at the range with my flintlock and was approached by an older guy. "Can you use some blackpowder?" was his question, and I replied that I could. He asked me to meet him at his place later, so I did. He had a plastic tub with lid sitting on a trailer behind his garden tractor along with a sheet of roofing rubber. "I had it down in the bushes in the woods, been there for at least 10 years". He opened the tub, and there was a heavy, black plastic bag inside, and it was tied shut. Upon opening the bag, it was evident there was water in the bottom. ".....insert your own expletives...."
The cans on top didn't look too bad, but there must have been at least a gallon of water in the bottom, and those cans were rusty. "....more expletives...., I'm sorry, but how could this happen? Well, if you think you can do anything with it, you can have it".
I loaded it into the back of my truck - tub, bag, and all. I placed the cans on my garage floor and got the questionable idea to blow warm air on them with a portable electric heater. I checked them several times, moving warm to the touch cans further away, and after a couple of days decided to see what was salvageable.
The cans that had been on top sounded like powder when shaken, so were dumped into 5 quart metal bucket for visual observation, beofre transferring into modern plastic powder containers and relabeled. This was mostly Goex ffg from '96 to '01.
Some of the rusty cans seemed like a solid lump. Elephant ffg and fffg from '96 and '97 were the worst. There were a few cans of Goex ffg as well, and one can of Goex Ctg from 1995. I beat on the cans with my hands to try to loosen the powder up, but then resorted to slamming the cans onto a 2x8 on the floor. I started pouring into the bucket, and broke up the lumps. Some of the cans needed the spouts and tops ripped out to get the big lumps out, but it eventually seemed to break up OK. This was all mixed together in one big jug.
There was a can or two rusted through, some that had a thick crust of blackpowder in the bottoms after dumping out what would come out. I ended up with one can of very questionable looking stuff that will be reserved for pan powder at best, or maybe will end up as fertilizer.
Patrick