Electro-Chem Etch Process
Picture #1 – Materials for etching assembled: etching machine, cleaner, etchant liquid, knives, electrode wrapped with felt cloth and stencil. Be sure to set the machine for etching or marking.
Marking leaves a black mark on the surface of the knife. Is made with an alternating current essentially the current moves one way and removes molecules of metal out of the blade toward the pad on the electrode and then as the current moves back it redeposits the metal back on the knife making the black mark in the shape of the stencil.
Etching uses direct-current flowing from the knife to the electrode. It removes metal from the knife and deposits it on the pad in front of the electrode. When the process is complete you will have an edge in the blade that you can feel.
The marking mode is very good for using on stainless steels, especially those that are highly resistant to corrosion. The etching mode is best used, IMHO, on carbon steels since carbon steels will patina. If you use the marking mode on carbon steel the mark soon disappears and blends into the patina. Oftentimes the mark disappears completely or blends into the patina to become un-distinguishable. The deep mark left by etching will not be lost in the patina; it will remain like a tang stamp. You would have to do a lot of deep buffing to remove a mark left with the etch mode.
Picture #2 – Preparation is always key. In order to get a good etch it requires a clean grease free blade. 91% to 99% isopropyl alcohol is one of the best and least expensive cleaners I have found. It leaves no oily residue as to petroleum-based cleaners like lacquer thinner. I wiped the blade to be etched with the 99% isopropyl alcohol and allow to dry, about 10 or 15 seconds, before proceeding to the next step.
Picture #3 – I put the stencil in position where I want it on the blade and hold it secure with a small strip of cellophane tape applied to the back of the blade with the edge overlapping to adhere to the back side of the stencil.
Picture #4 – I dipped the felt pad covering the electrode in the liquid etchant. It is important to get enough etchant on the felt that it can efficiently etch or mark the blade. If you have too much liquid it can get under the stencil or run off the edge of the stencil, on a larger blade, and etch the blade in places you don’t wanted etched! I know all too well!
Picture #5 – I attach the red lead to the blade, in the case of an assembled slip joint you can clip it to a secondary blade. It’s much easier than trying to get the stencil and the red lead on a small blade.
Picture #6 – Placing the moisten felt pad of the electrode on the stencil turn the unit on full power for the proscribed amount of time. My personal preference based on using this machine for seven or eight years is that when I am using the etch mode, I get the best results with most carbon steels using about a 20 seconds cycle of electricity before turning it off or simply lifting the electrode and pad off of the stencil. Longer than that I find tends to dry out the pad, damage the stencil and sometimes gives an indistinct etch and sometimes even leaves a haze around the etch.
Picture #7 – Since I am using etch mode, when I removed the pad from the stencil you can see a mirror image of the stencil in the pad created by the molecules of steel being removed by the direct-current and deposited in the pad.
Picture #8 & #9 – These are the uncleaned raw etches before cleaning and polishing. You notice I have not used the cleaner in the bottle on the left yet. This is where I use it. I usually use about a 4 x 4 rag, old T-shirt works great, and wipe down the blade thoroughly with the AMC cleaner. †This step is critical! The AMC cleaner neutralizes the electrolytes in the etchant. If they are not neutralized very well it will result in haze on the blade.
Picture #10 – The cleaned then buffed newly etched blade.
I hope this tutorial is helpful for those of you who are considering purchasing a machine to mark your knives, or for those of you who are merely interested in the process. This machine has other uses than marking knives; it can be used to mark tools also. If I had this Electro-Chem Etch machine when I was making my living out of the toolbox I would’ve used it to mark all of my tools.
I believe in marking knives I have customized for two reasons; #1 – because I’m proud of the work I do and my mark helps people identify my work; #2 – to prevent someone from knowingly or unknowingly selling a knife I have worked on and representing it to be a factory finished knife.
† Full Cleaning Instructions
The full cleaning regimen of a blade that has just been etched is as follows:
1 – Immediately after etching wipe the blade down with the AMC cleaner.
2 – Spray water on the blade and wipe it down with a paper towel. This is to buy time in the cleanup process if I am etching multiple blades, which I usually try to do.
3 – Take all newly etched blades and all items that have been in contact with the etchant, the little dish, the electrode, the felt pad and most importantly the stencil to a sink and wash them in warm water and dish soap. I usually use the felt pad as a washing sponge and squirt some Dawn dish liquid on the pad and use that to rub down the blades, the electrode, the little dishes and very carefully wash the stencil with the Dawn. Thoroughly rinse the stencil and pat it dry between two paper towels. Follow the instructions that come with the stencils for their care.
4 – Dry thoroughly all of the pieces you have just washed.
5 – Buff the newly etched impression in the blades. This is usually quick and easy unless you have used too much etchant and have shadow or clouding etches on the blade. For the Barlow blade I etched in this demonstration I buffed it from the top down, then flipped it over and buffed it from the bottom up (of course being careful not to get the edge into the wheel, it’s not a fluffy wheel). I use a rouge known as Black Magic that I get from Jantz Supply. The whole process of buffing the etch took about 30 seconds.