A trip through a demagnetiser can easily alter any iron items that have unwanted magnetic charge. The demagnetiser rapidly changes the direction of the current flow and erases the organisation of the magnetic domains. You can build one of these yourself with a few basic materials and tools. When you are finished building it, you will have to connect the wires of the demagnetiser to a power source like a battery to turn on the charge.
Wrap a piece of 1/16-inch brass around a wooden block. The block should be 2 ½ inches wide by 1 inch thick and 3 inches long.
Leave a 1/8-inch gap between the ends of the brass sheet when you bend it around the block and slip the wooden block out of the brass tube.
Cut two pieces of 1/8-inch brass to 3 ¼ inches by 3 inches with a saw. These pieces will be the braces for the demagnetiser.
Bend the brace pieces into a 90 degree angle. The bend should be made so one side is 1 inch long and the other is 2 inches.
Lay the two bent pieces of brass on a table so the 1 inch bent side is vertical and facing you.
Center one open end of the rectangular brass tube on one of the bent brace pieces.
Trace the shape of the tube onto the brace piece and repeat this process on the second brace piece.
Cut out the traced shapes from the braces with the saw.
Stand the brace pieces up so they are resting on the 1-inch sides, making little feet for the braces. The straight side of the braces should be facing each other.
Solder the rectangular tube inside of the brace pieces with a soldering iron. The tube should be lined up to the cut out holes, with the open seam facing upward.
Mount the brass form to a plank of wood by drilling through the brace feet into the wood with a power drill and screws.
Slip the wooden block into tube through the brace ends. This is the block that you wrapped the brass around originally to make the tube shape.
Cover the tube part of the demagnetiser of with several layers of thin paper. Wrap an 18-gauge single copper wire around the paper-covered tube several times. You should use a cloth-covered wire.
Attach two binding posts to the wooden base of the demagnetiser with the drill. Wind the loose ends of the wires to the binding posts. Each post should have one wire attached.
Connect the wires demagnetiser to a 110-volt circuit or battery which has a current of 3 ampheres. Put an object you want to remove the magnetism of inside the demagnetiser. The magnetic field inside the demagnetiser will destroy the magnetism the object has. Leave the object inside the demagnetiser for a few minutes, leaving the 3 amphere current to pass through the demagnetiser. Then gradually reduce the current and remove the object.
Check the wires occasionally and make sure they are still wound around the binding posts for effectiveness.
Always use caution when handling and working with electricity of any kind.