|couldn't be much simpler, could it?|
This will be done entirely with words- the photo above is the only one I took. I have tested this etching technique on stainless steel. I'm told it works equally well on copper, brass, and sterling silver. I assume it works on mild steel. In my tests, the charge only remained strong enough to etch about 6 inches from the source, in the above example, I had to turn my metal over after fifteen minutes to get both ends etched. A stronger power source might fix that, but I have not experimented. ALWAYS unplug your adapter before touching leads, metal, or solution.
What you need:
A glass or plastic container (ceramic is also fine, just no metal)
An alligator clip (this is not strictly necessary, but will make you life easier)
A 9V AC/DC converter. (You may have this around the house- my computer speakers were running off one. If not, order something like this:
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&pa=236937&productId=236937 ) If you're ordering it, order an alligator clip while you're at it.
some kind of resist (spray paint works, I'm looking for something better)
Something to scratch through the resist (I use a fancy printmaker's tool, but a needle shoved into an eraser works, too)
a sharp knife
some type of measuring spoon or cup
Start by mixing your solution
1. run warm water- this will make mixing in the salt easier
2. fill your container to whatever level you want it.
3. Mix in as much salt as will mix in without leaving a precipitate. If you're a measuring and numbers type, do about 1 part salt to ten parts water. Extra salt won't hurt, insufficient salt will hurt.
Now make your plug.
1-Using wire cutters, nip off the jack at the end of the cord- you won't need this.
2-With a sharp knife, make a notch in the thin plastic joining the two wires that were going into the jack.
3- Pull those two wires apart at least 18 inches down the cord
4-Using wirestrippers, expose about an inch at the end of each wire. If you don't have a good set of wirestripers, put the wire on a board, and roll it under the sharp knife, being careful not to apply so much pressure you cut the cord. Remember, you have plenty of length, here, so if you mess up, just cut off the end and try again.
5-most cords will not be marked negative and postive, so we'll just test it, now. Wrap each end of wire around a separate metal scrap (steel is cheap, but copper, brass, whatever you have around is fine)
6- put both pieces of scrap into your solution, taking care to make sure your wire leads are not dipped, and makeing sure that there is no direct contact bwtween the two leads or the two pieces of metal.
7-plug in your adapter. One piece of metal will have bubbles coming out of it, the other one is being etched. Take note of which is which, and unplug you adapter. Mark the wires.
8-Wrap the end that had the bubbles coming out of it securely around a piece of scrap metal. It does not have to be the same metal you're going to etch, but it does have to conduct electricity. Steel, copper, brass are all fine. If you can, drill a hole in the scrap and pass the wire through that, so you know you have a really strong connection.
9- attach the alligator clip to the other end. Depending on your clip, this may involve crimping or wrapping. If you don't have an alligator clip, wrap that end securely around a longish piece of copper wire. If you have to keep wrapping and unwrapping your original wire from each piece you etch, you will quickly break it.
Now you're ready to etch!
1- etch before you cut you metal down to size. This will allow someplace to clip. There are two ways to finish from here, method a and method b (and an infinite amount of other methods, but come on)
2a- Cover you entire piece, front back and sides, with resist. Allow to dry
3a- Scratch through this surface whatever design you desire.
4a- This will allow thin lines, legible text and a lot of control. The lines you scratched will etch.
2b- Cover the back and edge of your piece with resist
3b- Paint a design on the front with resist
4b- All the areas not painted will etch. This provides an interesting texture and allows for large, bold designs
5- Once resist has thoroughly dried, clip an edge of the metal with your alligator clip, or wrap the whole piece in your spare copper wire.
6- place the metal gently in the salt water solution, making sure that all areas you want to etch are under the surface. Try to keep the alligator clip out of the solution, otherwise it will etch, too.
7- place the scrap at the other end of the adapter in the solution, not touching the metal you wish to etch. Try to keep you wire lead out of the water.
8- plug in your adapter.
9- The first time you do this, check it in about five minutes. The etch will not be deep yet, just look and make sure your chosen resist is holding up. If any corners have pulled up, remove and try again.
10-if you know your resist works, check every fifteen minutes. Unplug the adapter before touching metal. Depending on the depth you desire, 15 minutes may well be long enough. Using a nail or something similar, gauge the depth of your etch.
11- Once deep enough, unplug your adapter, remove your metal, and clean off your resist (acetone works on spray paint)
12- Voila! You have etched metal