Hobbies And Interests
Things You'll Need
Instructions
Cut a circle of aluminum foil just large enough to cover the bottom of a wide-mouth glass jar. Cover the bottom of the jar and the dull side of the aluminum foil with contact cement. Let the cement set for 10 minutes.
Press the circle of foil into the bottom of the jar, smoothing out as many wrinkles as possible. Glue palm-sized sheets of aluminum foil to the inside of the jar until the entire inner surface is covered except the top inch of the jar.
Glue palm-sized sheets of aluminum foil to the outside wall and bottom of the jar until the entire outer surface is covered except the top inch of the jar.
Cut two discs of thin plastic. One disc should be slightly smaller than the inner mouth of the jar, while the second disc should be one-quarter of an inch larger than the outer rim of the jar. The bottom of a plastic container of ice cream or margarine is a good source of plastic for this step. Glue the two discs together, centering the smaller disc within the larger disc. This will serve as the lid to your jar.
Drill a quarter-inch hole through the center of the lid. Insert a short length of quarter-inch metal tubing through the hole. Solder a steel ball bearing to the top of the metal tubing and a length of copper wire to the bottom of the tubing. When the lid is placed on the jar, the copper wire should come into contact with the aluminum foil at the bottom of the jar.
Allow the assembly to dry for a day with the lid off. Attach the lid to the jar using silicone adhesive or superglue.