Damascus Knives & Re-Etchng

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Dave Martell

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The following is a re-post from a tutorial I wrote back in 2007. This isn't exactly how I do this these days, in fact I do it a lot different (using a tank that I hang the knife into and I buff the blade as a final process before sharpening) but that's because I work on knives for a living - not because this doesn't work. The following procedure is meant as a DIY project for a knife owner to do himself at home.

I hope this helps someone.

Dave








 
For awhile now I've been promising a tutorial on how to re-etch damascus knife blades. Many people have expressed interest in this since they have damascus knives that don't look as pretty as they once did. The wear/damage to the knife comes from typical scratches picked up during use as well as the dreaded "Oh crap - I slipped and scratched the side of my knife" while sharpening scenario. OK, I can hear it now, this nevers happens to your knives....yeah right....but for those of us who have had the occasional slip up this tutorial should help get your knives back in factory fresh condition.

I'm going to start off with a strong warning. DO NOT take this procedure lightly. DO pay close attention to the warnings I heed throughout. Serious injury can result to yourself, others, and to your property if you don't pay attention to safety!!

OK, now that I have your attention I'll start with a description of the process with some pictures of the process itself followed up by shots of the finished knife. I'll do a post for each step until I get to the finished knife. This will take a couple of minutes so sit back and hang in there.
















The knife I used for this tutorial is one of the most expensive knives on the market - a Hattori KD...in petty form. If I'm not mistaken the knife retails for over $300. This particular knife is well used and has scratches from use as well as a "high polish" job half way up the side of the blade.












The blade needs a bit of prep prior to etching. I like to use the least evasive technique possible. In this case I chose to use 600x wet/dry sandpaper that I bought at Lowe's some time ago.

I used a small piece (about 1"x2") sanding from bolster to tip until most of the scratches were removed and the polish section was close in appearance to the unpolished section. I did the whole blade like this.

Follow this with a good thorough cleaning with either a good quality alcohol (90% or better) or with acetone. Wipe the blade until all streaks, fingerprints, and marks have been removed. You want to do this right because any residues left on the blade will show during the etch.







OK....now the part to S-L-O-W down and think before proceding. You are about to use an acid which can hurt you, others, and/or your property. You must set yourself up in a place that is well ventilated, has nothing close by that can be ruined if a splash should occur, you should not allow children or pets into this area or anyone for that matter, you should wear crappy clothes, and should dawn safety glasses, chemical resistant gloves, and maybe even a face shield and rubber apron wouldn't be a bad idea either.

Do you get the point yet? This stuff is dangerous and should be respected during use.

Now for the solution...

1. PCB (printed circuit board) etchant/acid purchased at Radio Shack

2. White vinegar

Start by pouring a 50/50 mix of vinegar/etchant. Pour the vinegar in the container first - NOT the etchant I have never seen this happen but I've been told that to pour the etchant in first can cause a flash out when the vinegar is added. I don't know if this is an old knifemaker's tale or not but I don't care to find out and I suggest you play it safe too.

I'm using a Rubbermaid tub as a container but any chemical resistant container will do. Maybe clean out the container first to make sure there's nothing in the chemical solution your using.










There's different ways to go about applying etchant to the blade. Most people soak the blade in a container because some steels require a long soak to achieve the desired contrast. I've done it this way myself and still do when necessasary. How I do it most often though is to just wipe the blade with the etchant using a clean cotton rag. I try this first to see if it will take and then resort to the soaking method if required.

*Note -The reason why I prefer not to soak is it's difficult to get the solution level correct when standing (or laying) the knife in a container without contacting the bolster. This would be my prefered method if I could etch without the handle in place.

So you want to wipe the blade from bolster to tip with etchant. Keep the rag wet (not too wet though as to cause dripping) and keep applying the etchant ensuring to keep the blade free of too much build up and streaking. An even etch is what you're after.

When the blade starts to turn dark you are seeing the contrast begin to appear between the carbon steel (darker sections) and the nickel (lighter sections). Continue this process until the blade is a bit darker than what you expect to see when complete as some of this dark carbon will wash away when neutralizing.

Speaking of which, you will now take the knife to a sink (or hose) and rinse the etchant off of the blade. This is the point at which the etchant will stop working as it's been neutralized. Some people use baking soda either in place of water or in conjunction to water. I've never had to use anything other than water myself.

Now wipe the blade down with alcohol again, wipe dry, and oil. I like Camellia Oil for this but use whatever you want.













Now we're at the moment of truth - did it work or do we need to do it all again. Many times it does take a second etch to get the desired look and that's no big deal. Just wipe off the oil with alcohol or acetone and go to it again.

In the case of this knife it all worked out great after only 5 minutes of etching time. You can see the finished knife in the pictures above, all sharpened up, bolster shined with Flitz, and ready to be used again with pride.

The total cost in materials was less than $20 to make this $300+ knife look like new again.

So if you've got a damascus knife at home that looks a little uglier than you like just fix it!
wink1.gif
 
Thanks, Dave. It inspired me to do mine, for better or worse.
 
Dave, I have tried to etch some knives with stainless jackets, Carter, Hiromoto etc...every time I do it, it turns the stainless cladding an opaque color. I know you do a lot with Hiromotos, how are you avoiding discoloration on the stainless? Ir are you just refinishing the stainless after the fact?
 
Dave, I have tried to etch some knives with stainless jackets, Carter, Hiromoto etc...every time I do it, it turns the stainless cladding an opaque color. I know you do a lot with Hiromotos, how are you avoiding discoloration on the stainless? Ir are you just refinishing the stainless after the fact?


If it's etched quick you can buff or sand (really fine sanding like micro-mesh) the finish back to near stock look but if it's been etched to the point where the surface turns rough then you'd need to do a lot sanding (coarse/med - fine) to return it's shiny look.

I accept some darkening of the stainless as part of the process and don;t go nuts trying to remove it. What I prefer to do post etch is to bring out the shiny bits that remain raised and smooth the surface as much as I can without removing the look.
 
Just this week I thinned behind the edge of my nearly 3 year old Ironwood Tanaka. What a nail biting experience. I didn't test the waters or anything I just dove in headfirst by grinding away the bottom third of the blade face on my atoma 140. Yikes!!

I know you didn't want to do this for me last year Dave but I had to take a crack at it. I just needed to return some performance to the blade. It still gets super scary sharp no problem but was feeling wedgy through onions and carrots for a while now. So I ground her up on the atoma which obviously removed some cladding and the etch along with it. Followed that with a bit on the gesshin 400 then the bester 1200. The trick on the stones is to work the mud and use light to no pressure to achieve as close to kasumi as possible.

After she was all buffed out I had to return the etch which I have done myself before on a few blades so no problem there. Just followed standard prep and proper procedure. After finishing the etch it was just dark all over with no contrast. Very muddy and poor looking. No worries though. Break out the micro mesh and start buffing. Removing the etch from the raised spots returns the contrast. Then I break out the natural finger stones and polish for a bit. Clean her up with flitz and buff it off then clean with just hot water and dry with a towel. Then I just did my normal sharpening routine and got her screaming again.

It's not the original look anymore but I knew that going in. I am happy with the results though. It's not perfect but I like the wabi sabi it has now and it has grown on me.

Pics?
 
Just so you don't think it didn't happen.
IMG_20120513_230943.jpg

IMG_20120513_231008.jpg

IMG_20120513_230943-1.jpg

:D Not too shabby.
 
Thanks for the post Dave! As always, very well organized and thought out and very helpful! I had a Kitaji shig refinished to repair some pin-hole pitting in the cladding that happened during a very humid 2 weeks last summer. I know that it's not traditional, but I then had the blade etched with the muric acid/ PCB acid like in this post. WOW! really great results, the blade looked super cool, and more importantly the etched surface seemed to drastically reduce the famous shig reactivity and and slllooowww things down enough for a really solid and even patina to form over the etching without pitting or over oxidizing.

Anyway, just thought that it would be worth mentioning that, on really reactive blades, an etched finish might be a good alternative or edition to a forced patina.
 
When you are adding a acid to anything else (lets say water), you pour the acid in to the water. Other wise you will have a reaction of all the acid wanting to react to the first drop causing a explosion. :angryexplode::devilburn: It's been over 20 years since I took a chem. class, so I'm sure someone could explain it better.
 
Great post, Dave! I wonder if this would work on Shigefusas kitaeji as the cladding is.............. different than the usual stainless claddings. I dont wonna mess up the cladding.
 
Thanks for the post Dave! As always, very well organized and thought out and very helpful! I had a Kitaji shig refinished to repair some pin-hole pitting in the cladding that happened during a very humid 2 weeks last summer. I know that it's not traditional, but I then had the blade etched with the muric acid/ PCB acid like in this post. WOW! really great results, the blade looked super cool, and more importantly the etched surface seemed to drastically reduce the famous shig reactivity and and slllooowww things down enough for a really solid and even patina to form over the etching without pitting or over oxidizing.

Anyway, just thought that it would be worth mentioning that, on really reactive blades, an etched finish might be a good alternative or edition to a forced patina.

Got any pics?
 
If I'm not mistaken, the Kitaeji finish is produced by polishing, not etching.

Rick

That's how they come from Shigefusa... its a really impressive polish job and not one I've been able to replicate. I can mirror polish, but getting a natural stone finish that both shows the contrast in the blade and is perfectly smooth and even is... "tricky" to say the least.

I posted this in a different thread before, but here's the link to my shige with finish from polishing, etching, and then patina:
IMG_0107.jpg
gallery: https://picasaweb.google.com/117600618285187025883/MarkoShige#
 
That's how they come from Shigefusa... its a really impressive polish job and not one I've been able to replicate. I can mirror polish, but getting a natural stone finish that both shows the contrast in the blade and is perfectly smooth and even is... "tricky" to say the least.

I posted this in a different thread before, but here's the link to my shige with finish from polishing, etching, and then patina:
View attachment 7973
gallery: https://picasaweb.google.com/117600618285187025883/MarkoShige#

I believe the type of natural polishing stone is the determining factor. Not too long ago Dr Naka was kind enough to provide a set of three fingerstones to some of us. One, and only one, of the stones was capable of replicating the kitaeji finish, or at least that's what I found.

Rick
 
When you are adding a acid to anything else (lets say water), you pour the acid in to the water. Other wise you will have a reaction of all the acid wanting to react to the first drop causing a explosion. :angryexplode::devilburn: It's been over 20 years since I took a chem. class, so I'm sure someone could explain it better.

it's not just the possibility of a reaction, pouring the acid second can simply lead to a splash back. you don't want that either. AAA (always add acid).
 
That's how they come from Shigefusa... its a really impressive polish job and not one I've been able to replicate. I can mirror polish, but getting a natural stone finish that both shows the contrast in the blade and is perfectly smooth and even is... "tricky" to say the least.

I posted this in a different thread before, but here's the link to my shige with finish from polishing, etching, and then patina:
View attachment 7973
gallery: https://picasaweb.google.com/117600618285187025883/MarkoShige#

Hey that is a gorgeous knife it looks great!!
 
Hey So recently a Friend and I decided to give the etching a try. We tried the damascus first then got interested in trying some other things to like the white #2 and some Blue steel as well with different finishes I wish I had all the picks but the one I am most proud of is my Tojiro White #2 petty.
Then I gave it a little cleaning and took off the Kurouchi finish and then we etched it. Then I gave her a little love and polished up the Top to produce a mirrior-ish finish on the top then it goes to a light dim gray on the bevel then to a jet black on the edge. It looks sweet
I think its a pretty sweet Knife now!!
Thanks For the Inspiration!
 
Hey So recently a Friend and I decided to give the etching a try. We tried the damascus first then got interested in trying some other things to like the white #2 and some Blue steel as well with different finishes I wish I had all the picks but the one I am most proud of is my Tojiro White #2 petty.
Then I gave it a little cleaning and took off the Kurouchi finish and then we etched it. Then I gave her a little love and polished up the Top to produce a mirrior-ish finish on the top then it goes to a light dim gray on the bevel then to a jet black on the edge. It looks sweet
I think its a pretty sweet Knife now!!
Thanks For the Inspiration!

cool, but...

:needpics
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
I have an old Hattori HD5 I like to re-etch. I'm living in Sweden and we don't have radio shack, so what's the compound in the etchant you use? Iron chloride? Anyone have an idea on what grit finish it's on the HD series, 600 as well?

Cheers
 
I have an old Hattori HD5 I like to re-etch. I'm living in Sweden and we don't have radio shack, so what's the compound in the etchant you use? Iron chloride? Anyone have an idea on what grit finish it's on the HD series, 600 as well?

Cheers


Ferric Chloride is what we're using here. The level to which you finish your knife isn't as important as you finishing it as evenly as possible although it does help to go as fine as you can.
 
Naturally it's called ferric not iron... Thanks for the info!
 

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