By keith

Electro Etching

Some people have asked about the process I use to etch the Square K logo onto the knives. So here it is. I did a lot of research and looked into a lot of different commercial etchers, which run hundreds of dollars. But the concept is pretty simple and I found some schematics and parts lists on line and was able to make my own etching machine for around $60.

It starts with a knife with a polished, finished surface. This is the batch of K2s I’m currently working on. The handle will be worked on later, but the blades themselves are done.

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I bought a Silhouette Portrait vinyl cutter for around $100. With this, I designed and cut out the logo on an adhesive vinyl sheet. I can pop out the four shapes, leaving holes that will be etched into the metal. These stickers are one-time use but I can print up a batch of 20 in about three minutes, so no big deal.

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The other method of creating stencils is a photographic method. You print out your design on a clear sheet and this is put on top of a photosensitive material which is then exposed to light, creating a stencil. Using the photographic method, you can get much more detailed designs than you can with the cut vinyl, but with my logo being so simple, the vinyl works fine.

The stickers are then placed on the knife and pressed firmly in place. The surrounding area is also masked off to prevent any stray etching.

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This is the etcher I made. All parts from Radio Shack. It’s basically a 120 volt transformer that steps down to 24 volts. But it has a center tap so you can get either 12 or 24. I originally had it at 12 volts, then tried 24 and found that this tended to burn up the stickers a bit, so I put it back to 12 volts. There’s also a switchable bridge rectifier circuit to turn the AC into DC. That’s what that switch on the right is for – to choose AC or DC. DC etches, AC blackens the metal.

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The knife is hooked directly to the positive terminal. The etcher to the negative. The etcher is simply a small piece of brass hot glued to a wooden handle. A piece of cloth is wrapped over it and soaked with electrolyte specifically formulated for etching high carbon steel. There are various formulas you can use, as simple as salt water. I can’t say 100% that I’m getting better results with this electrolyte than I was with the salt water, but it works fine and I have it, so I use it.

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When all is set, you power it up, set the switch to etch, which gives you DC voltage, and press the etcher onto the sticker. The electricity sucks the metal right off the blade and deposits it into the cloth and onto the brass plate.

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I hold it on there for about 10 seconds, then release and repeat about 15 times. Here’s what it looks like after that.

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Then I switch it to “black”. This applies AC current, which results in carbon being deposited on the metal. I do about four 10-second shots of this.

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Take the sticker off and clean it up a bit, and there you go.

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Whole batch done in about fifteen minutes.

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The process actually etches into the surface of the metal. Not deep, but enough so you’d have a hard time sanding it out. The blackening process, however, is just carbon on the surface of the blade. It looks beautifully black at first, but will rub off pretty easily. Still, a good amount of carbon will lodge in the corners of the etch, giving it a nice distressed look. And I’m sure with time, a nice patina will form in the etched area, more than on the polished blade, giving good contrast.

Anyway, that’s the process.

Updates, K1 and K2

Well, it’s been a great few weeks since I started this site. I’ve sold nearly all the knives that were available or in progress, and finished up and shipped all those that were sold. I also started a new batch of knives, and all four of those are now sold.

Speaking of the next batch, I’m working on a new design. This isn’t a drastic change, but incorporates a few changes to aspects of the knife that, to me, stood out as having room for improvement.

Here’s a (non)artist’s rendering of the new design.

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The knife is approximately the same size as the ones I’ve been making. The blade itself is about 1/4″ longer and 1/4″ narrower, so overall it feels more streamlined. I’m also going with a Scandinavian or “Scandi” grind. This means that rather than beveling the blade for most of its width, it is only beveled on the last quarter inch or so. This adds additional strength, as you’re taking away less metal. Of course, for a fine slicing tool such as a kitchen knife, you’d want a thin, full taper. But for something that will probably see harsher work, the Scandi is a good choice.

Instead of the brass guard, I’m going with a brass bolster. It will still hook out a bit to give the functionality of a finger guard, but I think it looks much more elegant.

The handle is the same basic shape. The lanyard tube is a bit larger, and instead of three plain brass cutlery rivets, there will be two mosaic pins. Here’s what those pins will look like:

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All in all, I believe these changes will result in a much more refined knife. I’ve dubbed this new model the “K2”, which makes the original design the “K1”.

I’m not totally retiring the K1. If someone wants a K1, I’ll happily make them one. But I’ll be focusing on the K2.

Here are a few shots of the first one making its way towards completion.

First, the K2 template, compared to the K1.

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There’s a bit of perspective going on there that make the new template on the bottom look much larger then the earlier one on the top. If you lay them right on top of each other the new one is 3/16″ longer.

I start with a fresh piece of O1 tool steel, paint with Dykem and trace the outline of the template with a carbide scribe.

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Then I cut out the knife shape as close as I can. I’ve been doing this by hand so far, but I just got a metal bandsaw which is going to make this phase a whole lot easier.

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Then, onto the grinder, profiling down to the scribe lines, then rough grinding the bevel and drilling all the necessary holes.

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Then it’s into the fire for heat treating.

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Cleaned up, with makers mark etched in.

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And bolsters rough cut.

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And here the handles are going on.

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All that’s left now is shaping the handle and making the sheath.

The wood you see for the scales is Arizona desert ironwood. I’ve stockpiled enough of this to make four knives. I’ll finish this one up by the weekend and get started on the next three. This was a test of the new design and I’ve learned a lot of things that should make the next few go much easier.

When this batch is done, I’ll start another batch of four of the same, and I’ll hold the price for those at $125 + shipping. This batch sold fast, so let me know if you want in.

Evolution of a Knife

Raw 01 tool steel. 36″ x 2″ x 1/8″.

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Cutting and profiling.

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Beveling.

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Drilling and heat treating.

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Clean up after heat treatment.

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Fitting the guards.

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Handle work.

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Final polish and electro-etch maker’s mark.

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Making and fitting the sheath.

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Ready to ship.

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Knife Making – Tools and Skills

One aspect of knife making that is really attractive for me is the number of different skills and tool sets you need to accomplish the entire process.

Using the material removal method, you’ll use some or all of: a hacksaw, jewelers saw, band saw, drills, files, sand paper, angle grinder and belt grinder. All of these remove chunks or small bits of metal that don’t look like a knife and start to make the knife sharp.

Then for your various heat treating processes, you’ll need a torch or coal forge or kiln or heat treating oven, maybe a toaster oven for tempering, oil or something for quenching, and possibly other supplies depending on what kind of steel you’re dealing with.

You might be doing some soldering if you’re putting a guard on. More torch work, with solder and flux and more abrasive work to clean up afterwards.

The handle requires some more material removal skills – cutting, drilling, grinding, filing, sanding of wood, micarta, bone, antler or some other material. Making an attractively shaped and comfortable handle is an art in itself. And then you’ll need to know about fastening methods – prepping and application of epoxy as well as the use of pins, rivets, bolts or other fasteners.

Then finishing – the handle will need to be sanded down smooth and probably have some oil or other finish applied. The blade and any other exposed metal will need to have all scratch marks removed and sanded and buffed down to a satin or mirrored or stonewashed or other finish.

Sharpening and honing is its own skill with as many schools of thought and favorite techniques as any other technology.

Then, of course, you want something to carry your knife in. So there’s sheath making – leather work, which involves cutting, gluing, punching, stitching, dying and finishing leather, or maybe you want a Kydex sheath, which has its own techniques.

So generally speaking, you’ll be dealing with at least three different materials – blade, handle, sheath – each with it’s own technology and techniques. All that can be daunting at first, but take it one step at a time and pick up what you can. Each new knife you make, you’ll level up on several skills. And all those skills can be used for other things. I now have lots of other ideas of things to make with metal. I already do plenty with wood, and leather work opens a world of cool possibilities.

Wenge knife just about done

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Put some time in on this knife this weekend, in addition to working on the Japanese style tool chest I’m building to store my knife making equipment. That’s another “almost” this weekend.

Anyway, on the knife, I got the handle finished, sanded up to 800 grit, oiled and buffed out. Then polished the blade up to 1000 grit for a satin finish, electro-etched the Square K logo and buffed up the brass guard. I’m really happy with how this one came out. My best so far, as it should be.

This one is already spoken for, but it has three other siblings on the way that will soon be looking for good homes.

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All that’s left now is putting a real edge on it and honing it razor sharp. And making a sheath. Leather work is something I’m still getting up to speed on, but the sheaths I’ve made so far have turned out pretty well. Hoping I can level up a bit on this aspect too.

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Four knives slowly taking shape

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I’ve been working on these for way too long. This is all a very part time activity for me, after my full time job, and in addition to making programming videos at Coding Math and Egghead, and family activities (which include about two hours of dog walking daily). But, they are slowing taking place. Some more work has occurred since this photo and I hope that by the end of this week, the handles on these will be finished and they’ll all have the pins and thong tubes installed. Then, onto the leather work.