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This article describes how to make a flash blinder. A flash blinder is something that silently makes a very bright, directional flash of light, inducing temporary vision problems. Flash blinders can be made into jewelry, pins, etc. They can be worn on your arms, on your clothing, or held in your hand. If you wear them on your clothes, they should be positioned where they'll be at eye-level for potential thugs, and out of your own visual field.
Making Flash Blinders
This work should be done wearing sunglasses or oxyacetylene welding goggles, and under very bright lights. This is just in case your flashbulbs go off while you're assembling the jewelry. If possible, you and your work area should be grounded to minimize the chance that static buildup will set off the bulbs.
The glass part of the bulbs will be glued to the clear plastic after you cut it to shape. The foil will be the contact for the point of the bulbs, and the wire will be looped and twisted snug around the ground (barrel) contacts of the bulbs.
First, spray adhesive onto the sponge and stick the aluminum foil onto it. Follow the spray adhesive instructions, especially avoiding open flame as well as breathing the fumes.
Next, cut pieces of clear and backing plastic to match, then figure out how many bulbs you need for the piece you're making. Mix up enough epoxy to coat the clear plastic without dripping off. Tape your clear plastic to a level, disposable surface using electrical tape with the tape covering only the edge of the clear piece (about .125 in). Apply the epoxy to the clear plastic on a level surface (this makes the epoxy less likely to drip off). Keep a small sample of your epoxy on a plastic scrap, and test it periodically with another scrap. When it gets sticky and honey-like, stick the glass bulbs of your flashbulbs and the heads of several screws into the epoxy so you have a "forest" of bulb back ends and the threaded part of the screws sticking up with the bulb parts stuck to the clear plastic. Leave enough room between bulbs so you can reach in between them with tweezers or needle nose pliers.
Leave this assembly alone until the epoxy is set (see epoxy instructions).
Once the glue is set, use the copper wire to connect the barrel contacts of the bulbs by looping the wire around each bulb back several times, and twisting it around itself to make it tight enough to make good contact with the barrel contact. Keep the wire as close to the glass end of the bulb as possible and away from the screws.
Mark the position of the screws from the bulb assembly onto the backing plastic piece. Drill the holes big enough that lining things up will be easy. Use spray adhesive on the backing plastic to stick the sponge side of your foil/sponge sandwich to the backing plastic on the side that will touch the point contacts of the bulbs. The sponge is a spring to press the foil to the contacts. Trim the edges of the foil/sponge to match the backing plastic.
Poke a piece of wire into the edge of the foil in an over-and-under method, so it makes good contact with the foil. Keep a two-inch lead, and be sure that you have at least another two inches of wire lead extending from the bulb assembly in about the same area of the edge of the piece.
Gently squeeze the two pieces together until the screws stick out through the holes in the back, and put on the washers and nuts. Seal the edge of the piece with silicone, making sure the leads don't touch each other.
To fire the flashbulbs, you can use either an empty bic click lighter, attaching one lead to the gas tube and the other to the ground in the lighter, so that when you click it the spark goes through the leads. Or you can use four flashlight batteries and a doorbell button, or the like.
If you have the flashblinder on clothing, you should cover the back with silicone and cloth or fiberglass to protect your clothing from heat. Adhesive velcro or an old pin-on badge make good ways to attach it to your clothes. Route the wiring inside your clothes so you're not too obvious.
You can wear a flashblinder on a wristband. You can attach it to a walkman. Be creative, and make it fit in with your normal dress. Plan as much as possible to fire the flashblinder without touching it, say by having the button on a ring or glove. In a mugging situation you want to fire it as easily as possible. Once you have the piece set up, practice triggering it untl you have a smooth, unobtrusive motion.
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