Everything you ever wanted to know about a Silver Magnet but were afraid to ask:
(there was a url link here which no longer exists)
The Silver Magnet is a straightforward device.
It's a plastic box, about the size of a pencil box, with holes in the top and sides. There are two electrodes inside and a wire exits one end of the box.
Pour your exhausted fixer into an old bucket. I use a 5 gal. plastic bucket.
Submerge your Silver Magnet in the bucket of fixer. Plug the wire into the specially designed "wall wart" transformer and plug it into an electric outlet.
After several days, the silver in the solution will be attracted to the electrode inside the box. When you have gotten most of the silver out, unplug the device, rinse it with water and put it away for next time.
Dispose of the desilvered fixer in an appropriate manner.
Repeat this process every time you have used fixer to dispose of.
After a several uses, the box will be filled with metallic silver.
Pack it up in the envelope provided and send it in. The company mails you a check.
Use some of the money to order a new collection box. You don't need to buy another "wall wart" transformer. You keep it and keep reusing it.
Use some of what's left over to buy a case of beer.
The rest of the money can go toward film.
If you think about it, that film is essentially free.
