In California old or used anahydrous ammonia from blueprint machines is considered hazardous material. The engineering firms who use the machines have to pay some firm about $1 for each gallon to be disposed of. I usually go to the blueprint room of an engineering firm and pick up their old bottles for free, saving them the fee and storage space.

The old blueprint ammonia is really strong, and works excellant as a de-greaser prior to painting. I have dumped it into a large diameter PVC tube capped at one end, then set in balsa sheets to soak for an hour. The sheets are then very easy to bend or curl into position. It is stinky and must be done outside in a breeze. It is cheap, and easier than locating pure ammonia.

Wm.