Introduction: Acid Etching My Spyderco Endura 4

Picture of Acid Etching My Spyderco Endura 4

A documentation of my first time Etching a knife, I used ferric Chloride I bought on eBay on my spyderco endura 4.

Step 1: Preparation

Picture of Preparation

Start by disassembling your knife, using a T8 torx head for the pivot screw and a T6 for the rest - this size is pretty hard to come by but you can get them on amazon for less than £3. I used a flat head screwdriver and that worked but it did chew up one of the screws, luckily I could still take the knife apart.
Next take some nail polish and paint the areas you don't want to be etched (all contact areas - pivot, lock etc...) then if you choose to use the nail polish to paint a design. I didn't at first but I cant remember what I was thinking at the time. Use a cloth and some lighter fluid to remove any last grease from the blade before Etching.

Step 2: Etching

Picture of Etching

So my first tests, using 40% concentration ferric Chloride for 30 minutes I took the blade and clip out of the acid. I wanted a very dark, stone washed kind of effect but after sanding lightly with 1200 grit I was left with a matte grey all over which I was not happy with. I sanded it down as good as I could get it and started again. (you can use the acid a bunch of times before it loses its properties so there was no problem there)

Step 3: Attempt 2

Picture of Attempt 2

I chose to do some nice stripes for the second attempt, I learnt that Etching isnt as obvious as I imagined and it only looks good on a surface with a comparison, so after sanding down the old etch to 1200 grit I applied nail polish on the contact points and painted on my design.
Lighter fluid and a rag to clean the blade and clip then back into the acid, this time I took the clip out at 45 minutes, this was not enough time, I'm guessing because of the type of steel but the etch was very faint. However the blade I left in for an hour and that worked perfectly.

Step 4: Polish, Reassemble and Resharpen

Picture of Polish, Reassemble and Resharpen

I took out the blade and clip, used acetone to get rid of the nail paint and looked at my results, the looked alot deeper than last time and the contrast was much more easily seen, sanding and buffing makes the contrast even more clear and I thought it looked great.
I then resharpened the edge up to mirror polish and oiled the pivot area.
I would recommend this as an easy knife customisation and I will be doing it alot more in the future, thanks for reading and good luck!


Kona-chan (author)2015-10-25

does this work with a stainless steal blade with black coathing?

milo_baker (author)Kona-chan2015-10-27

you would have to remove the black coating

Kona-chan (author)milo_baker2015-10-29

that's kind of a problem, it won't even scratch

milo_baker (author)Kona-chan2016-02-18

should do if you get some sandpaper or a file

Kona-chan (author)milo_baker2016-02-19

the knife broke a while ago, the blade broke off the handle and my mom made me throw it away :/ maybe gonna buy a black sable soon

mhood6 (author)2016-02-10

what do you use for the acid? can you use a salt and water solution with an electric current?

milo_baker (author)mhood62016-02-18

I believe so but I've never tried, usually people use that technique when etching small, precise logos on their knives

M40 (author)2015-10-20

Ferric has always been my etchant of choice for steel and quite a few other metals. Time, temperature, strength of the acid, and the alloy/hardness of the metal being etched will ALL affect etching, so monitor carefully.

M40 (author)M402015-10-20

...almost forgot... AGITATION of the acid will produce faster, deeper, and cleaner cuts. An aquarium air pump sending bubbles over the piece works well, or simply frequent stirring/moving of the piece being etched. Also check for crud buildup in the exposed areas which can hinder etching. I pull the piece every 5-10 minutes and lightly brush it clean under hot water with a soft paintbrush. This allows you to check etch depth and edges.

steve.fenster.5 (author)M402015-10-20

What did you use to make the blades before etching?

M40 (author)steve.fenster.52015-10-20

I work in various grades of steel... mostly 10 series and various spring steels. I have a forge, but for the most part I use stock removal methods to shape.

steve.fenster.5 (author)M402015-10-20

Sorry! I meant what do you MASK the blades with before etching?

M40 (author)steve.fenster.52015-10-20

Masking materials vary widely. I’ve used different paints with varying levels of success. I've coated blades in Wal-Mart spray paint and then scratched the etch area through the paint with a fine needle file. I've even used paint markers to draw on a blade.

However, I've settled into using sign vinyl. This is sticky backed vinyl that is available at any place selling sign making supplies. You can buy sample packs of it on ebay (search for “sign making vinyl”). There’s also plenty of tapes that work as well (electrical tape, packing tape, scotch tape… pretty much any sticky back plasticized tape will do).

The first etches I did were done by cutting out designs with an X-acto knife, but I eventually graduated into a plotter cutter so I could design on the computer and then have the cut done by machine. I started with a little desktop cutter package, and upgraded last year to a large free standing cutter.

Tehemton (author)M402016-02-08

An easier way to do it is to take a printout on a magazine paper using a laser printer. Then place it over the blade and apply acetone on the back ensuring that the paper doesn't move. Once the acetone dries, you could remove the paper gently and wash the blade under hot water and remove any paper that sticks on. What remains is your steel with toner stuck onto it. Just ensure that you mirror the design before the print. We use this method a lot in PCB making at home.

M40 (author)Tehemton2016-02-08

I've been meaning to try the toner method. I've seen people use heat to transfer the toner... hadn't heard of the acetone method.

Also, I know it works for PCB's... BUT... copper etches very fast as compared to steel. I'll need to see if it holds up to an hour or more in the etch tank. Any thoughts on this?

Tehemton (author)M402016-02-14

Also I mentioned the acetone method is because using heat to transfer the toner on the blade could mess up the temper if done improperly. There was a great instructable a while back for making PCBs at home using the acetone. It basically dissolves the toner which then sticks onto the metal instead. Just make sure not to move the paper till the acetone has completely dried off

Tehemton (author)M402016-02-14

I once used it on a keychain I made out of left over steel a couple of years back.. I used the salt water and battery to quickly etch the logo onto it.. Ferric chloride should work equally well I suppose.. Just keep the printer on the darkest possible settings.

milo_baker (author)M402015-10-27

I didn't know that, I'll be sure to try next time

milo_baker (author)M402015-10-27

those look amazing

CJStephens (author)M402015-10-20

Did you etch those blades man? they look amazing!

M40 (author)CJStephens2015-10-20

Made them, etched them, sheathed them. I've been a "basement bladesmith" for almost 20 years. Photo below is my most recent project... a celtic style short sword in 5160.

WOLFMANNACTUAL (author)M402015-10-23

Hey, M40. I follow your instructions on knife making and modifications on your site. I have found your instructions very helpful and constructive. They have sure helped me save a boat load of money. How would I go about acid-etching a long sword?. The sword is blade is 36" long and is 3 and a half inches at it widest point. The blade is made out of high-carbon steel. David Wachter

M40 made it! (author)WOLFMANNACTUAL2015-10-24

David, I decided on an upright cylinder for my long blade etch tank. I picked up a 3 foot long clear PVC pipe with 3" ID. I can fill it with about a gallon of ferric, so it maximizes the length of blade I can etch without requiring huge amounts of etchant. If your sword flares to 3.5", then you'd need a 4" ID cylinder, and about 2 gallons of etchant.

JuriM (author)2015-11-04


JuriM (author)2015-11-04

bumbarass man

JuriM (author)2015-11-04


ewautvanwassenhove (author)2015-10-22

that's super cool! Do you think it could work on surfaces that you can't dip in the acid? like a dobro with a steel body? like then wipe over it or something?

thanks man, as for your question I would say probably, try it on a small scale first but I can't see a reason why it wouldnt work, let me know if you do and how it went

loony1 (author)2015-10-18

Why exactly the zip ties?
The acid etching turned out real nice. I like the tiger stripe pattern.

milo_baker (author)loony12015-10-28

thanks bro

CorgiCritter (author)loony12015-10-19

You snag them on your pocket and it opens the knife as you pull it out. The mod is known as the Ghetto Wave, since it's a homemade version of the Wave Shaped Opening Feature.

DIY Hacks and How Tos (author)2015-10-17

Those etching effects look great.


Bobby T (author)2015-10-22

Great results there lad. Did you test the blade in the first time, or did you use a test metal part

milo_baker (author)Bobby T2015-10-27

thanks, unfortunately i tested the blade the first time, using another piece of steel would be a lot smarter

Diesel Weasel (author)2015-10-17

Just a quick warning: Putting zipties on a knife like that can be illegal. Please check your local laws.

ablum3 (author)Diesel Weasel2015-10-21

I can understand that in some restrictive states such as CA, NJ, CT, NY etc.. However, most of Emerson knives all have a tab cut (known as the "Wave Feature") on the top of the tang that when carried in a pair of denim (or thick material) jeans, they open upon deployment.

silkier (author)Diesel Weasel2015-10-20

That's odd, I just reread the 'ible and it is quite clear that the zip ties were used to hold/suspend the parts for etching. After reassembly they are not there, so what exactly are you on about?

I have never heard of a waved knife being illegal. Never.

pyrocop1 (author)Diesel Weasel2015-10-18

Just wondering what part of the world it is illegal to place a zip tie on a knife, also why is illegal ?

rafununu (author)pyrocop12015-10-18

It's illegal in Diesel Weasel country and why ? Because of course.

CJStephens (author)2015-10-20

Really good instructable! Love how it came out it looks good on that endura 4.

Tooreal (author)2015-10-20

Great Knife Mod..

stonecold5445 (author)2015-10-19

its ;look great

CaseyCase (author)2015-10-17

All hail the mighty zip-tie mod!

About This Instructable




Bio: South East London, dont upload much
More by milo_baker:Easy File KnifeMy first knifeAcid Etching my Spyderco endura 4
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