Pimp Your Knife: Acid Etching

This is the second in a series of posts about knife modifications you can do yourself, A.K.A. pimping your knife.

(***The acid used for acid etching is very strong. Always wear rubber gloves and goggles to protect your skin and eyes while acid etching.)
I mentioned last week that quite a few people around here are into knife modifications, and here’s more proof of that.
Parker has another knife I’ll talk about later in the post, but first, here’s a look at a knife that’s been modified by Spencer, another Blade HQ team member. Spencer is really into experimenting with different ways to do things, and he’s made modifications to about 12 of his knives. In fact, while I was writing this post, he modified yet another knife.

Background Info

Spencer’s awesome knife (pictured above) is actually a combination of two different knives:

Boker Kalashnikov Automatic Knife                      Boker Kalashnikov Automatic
Limited Edition Stonewash                                    Knife Tanto Tactical

As you can see, he took the handle from the knife on the left, and the blade from the knife on the right.
The Kalashnikov blade he used is AUS 8 steel. I don’t want to go too in depth about different steels, but Spencer said different steels will etch differently in terms of color and darkness.  The strength of the etching solution you use for this modification might affect the etching as well. To give you a small idea of how different steels react, here are two other types of etching Spencer did and how they turned out:

1. Zinc Alloy buckle – took on a copper look
2. Kershaw Skyline (14C28N) – etched very quickly, turned dark grey

Acid etching is very much a trial and error process because different materials produce different results, but when  you get it down, it sure looks awesome.

How to do Acid Etching

***Remember: dissembling and/or customizing your knife will void any warranty that is applicable to your knife. Don’t dissemble, acid etch, or modify your knife if you’re planning on returning it.
1. Dissemble the knife. This will make your work easier, but it will also prevent the acid from coming in contact with the handle and doing strange things to it.
2. Remove blade coating, if there is one. Not all coatings come off, but Spencer used liquid powder coat remover to remove the coating on his blade (liquid powder coat remover works to remove powder coatings and Teflon). Make sure your blade is completely dry before continuing to step 3.
3. Get or make a vinyl design for the blade. Spencer has a USCutter TC Series Vinyl Cutter, which makes this step a lot easier. It’s basically a machine that allows you to cut various designs out of vinyl. If that didn’t help you, it’s akin to a Cricut, only a lot manlier. And mannish. And masculine. And macho. Chuck Norris probably uses one.
Anyway, if you can, use semi-permanent vinyl because later, it will peel off the blade much easier than other kinds of vinyl. Make the design (or designs) of your choice and once it’s done, peel it off, stick it on the blade, and smooth it out, making sure there are no bubbles in the vinyl.
If you don’t have (or know anyone who has) a vinyl cutter, you can always get in touch with a local sign maker or someone from a vinyl sign website. You’ll want to check with them to make sure they can cut your design to the right size. If you’ll be etching copyrighted or trademarked material, you’ll also want to make sure it’s something they will be able to cut for you.
4. Clean the blade. Make sure the blade is clean and free of oil and grease before continuing. Clorox wipes and Windex work well for cleaning.
5. Begin the etching process. The acid etching will need to be done outside or in a well-ventilated area, and you should wear rubber gloves and goggles from here on out. In your well-ventilated area, mix together one part muriatic acid to two parts hydrogen peroxide in a container that’s big enough to fit the whole blade. As an alternative, you can use PCB Etchant Solution, which Spencer found at RadioShack. Dip the blade into the mixture, making sure the whole blade is submerged in the liquid.
6. Watch and Wait. Think of the highest maintenance person you know. Now name them “acid etching.” Like a high maintenance friend, acid etching really demands your whole, constant attention, and you can’t leave once you start the acid etch. Once the blade is in the mixture, you should begin watching it immediately, checking on it every 30 to 60 seconds or so. When the etching is as dark as you’d like it, you’re done and you can remove the blade from the mixture.
7. Rinse off the blade. Be sure to rinse the acid off the blade with plenty of water after you’ve finished to negate the acid etching process.
8. Wipe down the blade. You’ll probably want to wipe the blade down after the etching process has finished, mostly for looks. Gun oil and WD40 work well. You might want to assemble the knife at some point—just a hunch.

Acid Etching by Hand

This is Parker’s knife, and he actually made the design by hand, which is pretty cool. His knife used to look like this:
Zero Tolerance 0200 Manual Military G-10 Folder Knife

This ZT has a 154CM stainless steel with a  tungsten DLC coating. Obviously a powder coat remover won’t work with this type of blade. Instead, Parker had to buff off the coating before he could begin acid etching.
For the most part, Parker’s steps for acid etching are very similar to Spencer’s, with the exception of how he made the vinyl design, of course. Here’s how to make a design by hand, like Parker did.
1. Get a sheet of vinyl. Vinyl is fairly easy to find. Many craft stores have it in stock.
2. Draw your design. Parker created his own stencil for his design, but if you don’t feel like you need one, you can draw your design directly on the vinyl and skip to step 3.  To create a stencil, draw your design on a 3×5 notecard, or something similar, and cut it out. Then, trace your design onto the vinyl.
3. Cut out your design. An X-Acto knife works well for this. Keep in mind that any part of the blade that is covered by vinyl will be untouched by the acid and will not change color, while any parts that are not covered by vinyl will become lighter, due to the interaction with the acid.
4. Place the vinyl on the blade. Peel off your vinyl design, and stick it on your blade. For this step, Parker peeled off the parts of his design that he wanted exposed to the acid and tossed them aside. Then, he used some Press’n Seal wrap (found near plastic wrap and aluminum foil in the store). Place the sticky side of the wrap on top of your vinyl design that you haven’t peeled off yet. Smooth it out over the whole vinyl design. Then, slowly lift up the Press’n Seal, making sure your design is coming up with it.
Once you have all of the design off of the vinyl backing, place it onto your blade and smooth it out, making sure there are no bubbles. (This is important because acid can slip under any areas that have bubbles.) Using a credit card to smooth out the bubbles works really well. After everything is smooth, slowly peel off the plastic wrap, and the vinyl design should be left on your blade.

From here, you can follow steps 4 through 7 listed above. Don’t forget to wear your gloves and goggles! Just a couple of things to note though: Parker used a tall vase to put the etching solution into. He also put some plastic-coated paper clips together into a chain and attached it to his blade to raise and lower it, so he really didn’t have to come in contact with the acid at all. He also polished up some high wear areas on his blade before reassembling his knife, and he used Flitz knife wax on the blade.

Final Comments

So that’s acid etching—I know this was a pretty long post, but I wanted to show that there are different ways to go about acid etching. It’s really not as intimidating as it looks, and it can be done in a short amount of time, which is a bonus.
Moral of the story: pimp your knife!