I thought I found it somewhere but now I can't.Isnt there a way to make a PC powersupply into an etching machine? I have to look but I think it's 3V dc out @14 amps ? A little help for the electricly challenged please.
Joe
Here is instruction on one I built many years ago and still use. I now use commercial electrolyte and stencils but the machine is the same.
Jim A.
For those of you who are looking for an inexpensive way to put a makers mark on your knives and dont want to put out a lot of money, here is a project you might enjoy. It will mark most metals but seems to work best on ferrous metals. You can mark your knives, golf clubs, automobile wheels and fire arms (not blued metal) and just about any bare metal surface.
There are many ways to make a mark on the blade of a knife but I venture few are as cost effective as using an electric etch setup.
To make the explanation short, electric etching is the opposite of electroplating. You put two dissimilar metals in an electrolyte and pass direct current through them, the positive electrode gives up ions and erodes and the negative electrode gains ions and is added to. The following is a description of how to construct and use an etching machine. Please read carefully before starting to buy any parts and make sure you follow the safety precautions!
************************ Safety Warning! ***************************
The source of power for this machine is 117Vac from a household electrical outlet. If you are unfamiliar with wiring or electricity make sure you get assistance from someone knowledgeable. 117Vac can be fatal!
************************ Safety Warning! ***************************
ETCHING MACHINE CONSTRUCTION AND USE
ITEMS NEEDED FOR CONSTRUCTION (refer to drawing before reading)
1. Door-bell transformer (they are current limiting and just what you need).
2. A power cord with two-prong or three prong plug.
3. A rectifier diode, 1 amp current rating or above @ 50 Volts or above.
4. Two wire leads with clips on at least one end. AWG 24 (24 gage) is large enough but larger is OK if it doesnt get too stiff. Preferably one black and one red.
5. A block of aluminum.
6. A piece of metal bar stock (preferably stainless) about 2 wide and 4 long.
7. A piece of thick felt (1/16 to 1/8).
8. Stencil (see below for description)
9. A heavy rubber band.
Item 1 Transformer can be obtained your local hardware store or building supply. These usually have three terminals, arranged in a triangular pattern. There are many different manufactures so look for the following. Between the left most terminal and the next (usually the top of the triangle) there will be marked or stamped 8V, between the second terminal and the third a marking of 16V and between the left and right terminal a marking of 24V. The transformer terminals may be marked 6V, 12V, and 18V respectively. This will also work.
Item 2 Power cord can be an old cord off most any electrical appliance or a $2 extension cord with the receptacle end cut off. Flexible is better than stiff.
Item 3 & 4 Usually Radio Shack will be the most available source for a diode. They also carry clip leads already made up. They sell a 2 pack of 3 amp 200V diodes #276-1143 for about $1.20 . A six pack of 40 long jumper leads #278-002 runs under $5. They also carry a variety of clips should you wish to assemble your own.
Item 5 You can make the electrode from most anything made of aluminum that is a convenient size to hold onto, and has a flat surface of at least 1/2 by 1 1/4. This could be a section of aluminum angle with a wooden or plastic handle attached or a block of aluminum.
Item 6 A scrap of bar stock, sanded to 320 grit, works well as a work electrode.
Item 7 Felt can be purchased at any sewing material or craft store.
Item 8 The stencil material is available from most of the places that sell knife making supplies. It is usually found in the section of the catalog with the etching equipment. A supply big enough to do a couple hundred knives will cost less than $10.
Miscellaneous items need for construction:
Screw driver for mounting screws
Soldering iron and solder (rosin core) or crimp tool
Barrel type butt splices, & crimp on lug for ground wire
Electrical tape or heat shrink tubing to insulate the exposed wiring
In-line switch or switch and mounting box with cover.
A base to mount the transformer on.
1. Mount the bell transformer to a piece of scrap wood for a base. Use round-head wood screws or sheet-metal screws.
2. Connect the input power wires to the two pigtails coming out of the back of the transformer using either crimp type barrel connectors, or solder. Cover the solder joints with tape or heat shrink tubing. I dont recommend twisting the wires together and taping them, this is a good way to get shocked! I recommend you add a switch between the power cord and the transformer. Place the switch in the hot lead. This will be the one that runs to the narrower of the two flat pins in the plug. If you use a three prong plug and cord, hook the green (ground) wire to the case of the transformer. You may have to put a lug on the end and slip it under one the head of one of the screws holding the transformer to the wood.
3. Cut one of the test leads (preferably black) about 6 from one end and solder the diode in the gap. Some heat shrink tubing or electrical tape around the leads will be needed. If you look at the diode there will be either a band around one end or a symbol on the side depicting an arrow pointing toward a bar. Solder the long piece of the test lead you cut off to the end of the diode that has no band (the arrow points away from this end) Solder the other side ( band side) to the short end of the lead. Now hook the short end to one of the terminals bordering the 16v or 18v markings. This will be the negative lead. Take a red lead (or something a different color than the negative lead) and clip it to the terminal on the other side of the 16v/18v marking.
If you are confused about the diode hook up try this. Take one black lead and cut it in half and solder the diode in between the two halves. Tape over the leads to prevent shock, or cover with heat shrink tubing. Hook one end to the transformer and the other to the electrode. Try to etch on a piece of scrap metal, if it works you guessed correctly, if not disconnect the lead from the transformer and the electrode and swap ends. It should now work! Mark the ends for future reference.
4. For the electrode, take the aluminum block and sand or cut it to a dimension which covers your logo or name on the stencil material with about a 1/8 extra on all sides. If it is too big it will get in the way or even hang over the edge of the stencil and cause unwanted etch marks! Something the size of your typical rubber-date stamp usually works well. An insulated handle will reduce the chance of getting shocked. A couple wraps of electrical tape will usually do the trick. The easiest way to connect the lead to the electrode is to drill a hole in the top or side and screw in a self-tapping screw. Hook your negative lead to the electrode (screw). Now cut a strip of felt the same width as the electrode and about 2 1/2 long. Place this strip across the bottom end of the electrode and secure with the rubber band. A slight depression or groove cut around the electrode about 3/4 from the contact end will aid the rubber band in holding the felt covering in place. It needs to be fairly tight.
5. Now for the electrolyte. Get a small clean dish (not metal) about three inches across (an old cream-cheese tub work well). Put about a 1/4 of warm water in the bottom. If you have access to an ohmmeter, place the test leads down opposite sides of the dish so the points are resting on the bottom. Turn on the meter and slowly add salt until the resistance drops below 20,000 ohms. Each time you add a dash of salt stir the solution. It only takes a small pinch of salt so dont get carried away. Too much salt makes the etch uneven! If you dont have a meter you can start with a pinch of salt the size of a pea and work up from there. Do test etches on the type of material you intend to etch !
6. Before you plug in the transformer, you need to make yourself a stencil. Take a piece of stencil material and type or write (using a ball point pen) your name or whatever you wish on it. If you use a computer with a dot matrix printer, you can print your name, logo, or anything on the stencil. Just tape it to a piece of paper and print directly on it.
Tips on use
I find the easiest way to make contact with the positive lead is to clip it to a piece of blade material (Item 6). I lay the blade of the knife on this metal plate and usually put spacers underneath the plate so the blade lays flat on it, and the handle rest on a solid surface.
Dip the felt covered end of the electrode in the salt-water solution and draw across the edge of the dish to pull out excess. You want the felt nice and moist but not so wet that it runs out of the felt onto the knife blade.
Once the stencil is made, and your electrolyte is mixed, hook the positive lead to the plate and rest the knife blade (or test piece) on the plate. Hold or tape the stencil to the knife blade (taping works well because you can lift the stencil up to check the etch and return it to the exact position if more etching is need). If you installed a switch on the transformer, make sure it is off and plug in the transformer. Now dampen the electrode felt, place it over the part of the stencil where the name is written and turn on the switch. If you didnt add a switch, just plug in the transformer and set the electrode down on the stencil as above. I find with my rig, 15 seconds gives an adequate etch. You need to experiment on scrap until you have the process worked out! It is a pain to have to regrind the blade to remove a bad etch!
Since the electrolyte is salt water you need to rinse the item being etched thoroughly in warm water after etching to reduce the chance of rust forming. A light coat of oil rubbed into the etch then wiped off seem to keep the rust away!
I make no claim as to how useful this etching set up will be to you, or whether you will like it. I use this setup myself an all my knives and havent had any problems.
Remember to read all the instructions prior to starting and obey the safety precautions.
