GENE MARTIN


MAKING YOUR OWN ETCHING MACHINE
Clint Breshears, has devised an inexpensive method of electro etching his trade mark into a hardened steel blade. Buying the commercial unit is slightly expensive, but Clints' machine does the job for well under a hundred dollars.

He begins with a d. c. power supply, which should put out between 20 to 28 volts, at a minimum 2.5 amps on the output side, maybe more but not less. The power supply must be well filtered to give the best results. Many electronic surplus shops have brand new power supplies on the shelf for around twenty to thirty dollars, and they'll work just fine.

Clint connects the positive output wire to a copper contact plate and the negative output to the handpiece holding the electrolyte.

This handpiece is a wooden handle, flat across the working end, with a stainless metal facing on the working surface, connected to the negative output wire. Don't make the working end too much larger than the trade mark that you plan to use.

Cover the working surface of the handpiece, with it's stainless layer, with a single thickness of felt. It's available in some hobby or yardage shops. It may simply be fastened with a rubber band.

Moisten the felt with electrolyte, but don't get it dripping, just moist. If there's enough moisture on the felt to wick through the stencil and spread out, you'll get a big, black mark wherever it spreads.

Tape your prepared stencil firmly in place on the knife blade, and check to see if it's straight. Once the etching begins, it's too late to make corrections. Place the knife blade firmly atop the copper contact plate.

Clint suggests that you press the handpiece down on top of the stencil with a fairly rapid off and on motion. The current actually vaporizes electrolyte and metal as it etches, so the off and on application of the handpiece allows gasses to escape but delivers plenty of current. Try it with about forty "touches", then peek underneath the stencil by lifting part of the tape at one end. If it has cut deep enough, quit. If not, press the tape back down and try about ten or twenty more touches of the handpiece. Never use a tiny stencil with a larger handpiece. It'll etch wherever the electrolyte makes contact with metal. You also have to be careful to make a good contact with the base plate, If you wiggle the blade around on it, you'll get etching marks on the part that moves against the plate.

When you've finished a batch, rinse the stencil out very thoroughly with a mixture of dish washing detergent and water, blot and dry. The tiny openings in a stencil clog with metal particles as you work, so don't try to do too many blades with one stencil in one session.

Both the contact plate and metal part of the handpiece will collect a lot of chemical residue from the electrolyte while it's working. Clean both handpiece and plate regularly.

If your etch shows a slight halo around the letters, a quick buff with green chrome compound will brighten it again, but go easy on buffing over the etching so the crisp letters don't get blurred.

Never touch the handpieces' metal plate directly to the contact plate. You'll burn out the power supply in a flash.

The electrolyte used to conduct the current that does all the work is corrosive and must be cleaned up with some sort of neutralizer before it does more than just etch.

If you use an etcher with the AC option, for coloring the bottom of the mark, be sure to neutralize that part of the blade thoroughly. What happens in the AC cycle, is the current deposits black iron oxide salts to create the color, and they will eventually rust if not taken care of.

NEVER TOUCH THE METAL FRAME OF THE POWER SUPPLY WHILE ITS PLUGGED IN, UNLESS YOU ENJOY LIGHTING UP LIKE A CHRISTMAS TREE.

BOOKSHELF

This web page was created by Zoe Martin
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