Experimenting with Etching

Having seen this come up from time to time, but never having tried it myself, I decided to give acid etching a knife blade a try. My “homework” consisted of cruising the internet looking for detailed how-to instructions. I found two methods being predominantly used. The first involves bluing the knife, then bring it in contact with bleach to initiate a chemical etching reaction. The second method is using PCB etchant for electronic boards. The blade is soaked in the etchant, neutralized, and that’s pretty much it.

With three blades sitting in my drawer, two Moras and a Lauri became my test subjects. After a quick cleaning with acetone, I used nail polish to protect the areas where I did not want the acid to penetrate. This is a common method of protecting areas of metal, but I also saw people doing the same with petroleum jelly or paint. Going for a random pattern on the blade, my worst mistake of this project was not layering the polish on thickly enough on the edge. I used two coats on the edge itself, but as you’ll see, this didn’t provide adequate protection, and the etchant caused damage to the blade edge. All the damage done was correctable by grinding the edge back slightly further on the knife, but it was extra effort that would have been unnecessary with better prep.

Once the nail polish hardened, the knives went into the etchant for just under 1.5 hrs. After that, I thoroughly rinsed the blades with hot water. Using nail polish remover, the nail polish was stripped off the blade, leaving high points where the acid had not come in contact with the blade at all. This is where I discovered the edge issue, and had to put the edge back on them. I also hit the sides with an 800 grit belt, and that was about it. With a few tweaks to the technique, this could be a very simple and interesting mod to give a unique look to a blade.