Etching Mokume

[Frank Niro]

I did use some mokume long ago when I didn't have the power of the forums for information. I believe I used some diluted muriatic acid (HCL) I do have on hand some Etchant and ferric chloride which I believe are much the same. I would certainly appreciate suggestions on what has worked well for others on the amount to mix with water and what sort of time it will take to get a good etch. Thanks Frank

[papi]

Frank, you don't need to etch mokume, it colors itself by natural oxidizing, patination, just leave it for a week and it will look very nice.

[papi]

on the other hand, some acid could speed up the process, but definitely no Ferric chloride, it will look bad with it...
at least what i remember from my experimenting...

[David Broadwell]

Frank,

Most mokume used by knifemakers is copper and nickel silver (and sometimes with brass added to them). Is this what you are using? If so, Papi is correct, you don't have to etch it. The copper will tarnish quickly and you'll be able to see the pattern. You can speed it up a little by rubbing it a couple of times a day with your hands. You can probably really speed it up with an oxidizing agent such as cold gun blue, a brass blackener, or liver of sulfur.

However, you can etch mokume to get different a different effect. I do it more than just polishing and letting it tarnish. I have an old bottle of ferric chloride that I once used for damascus but had grown very weak. It will dull the nickel silver and eat away at the copper at a faster rate. If there is brass in your mokume it will etch somewhere between the other two metals. Sometimes I'll just etch the mokume for a minute just to frost the copper and start the oxidation process, and other times I'll etch it for several minutes to remove enough of the copper so it is topigraphical like damascus steel.

I also tend to give my mokume a patina, especially after a heavier etch. Birchwood Casey cold blue works well. Play around with it and burnishing it with 0000 steel wool.

A couple of things about your etchant. DO NOT use the same etchant for mokume or other copper based alloy and damascus steel. The etchant will keep copper in suspension and deposit it on your steel. Also, don't use ferric chloride where you have silver solder.

One good thing about etching mokume is that if you have etched it and don't like it, it isn't hard to polish out and try something else.

Hope this helps.

David

[Frank Niro]

Thanks!
I definitely want the relief look as when Damascus is etched. Some important warnings there, David, that always make the work come out better !!! And papi, David agrees with you that your way is also a good way to go. I will run a test piece for sure. Perhaps a month or so down the way I will be able to give you a look at what was the result I got. Frank

[David Broadwell]

Frank, besides the patterns you see in it, what I like best about mokume is that it changes. I like metals that will take on a patina, which is why I like using bronze so much on my art knives. Good mokume gives makers like us many ways to finish it. You can buff or hand finish it and let it oxidize naturally, you can etch it, you can chemically patinate it. It is easy to do the basics with it, but you can experiment and find new ways to work it. It's one of those materials that begs to be played with, so do it.

Post some pictures and let us know how your experiments work.

David (part time mad scientist in a lab!)

[Frank Niro]

Hi pepi and David.
It did go very well and got me to the finish I wanted without a lot of trial and error. I went with whast I thought was a weak solution of ferric chloride and etched for about 6 or 7 minutes. I then rubbed them down with 0000 steel wool. I had the urge to stay with just this one today. I usually work on several different ones as I go along. It's near finished alright. I don't do pictures myself but my great friend Ron Lockhart will soon have it and he does in my opinion a very fine job of those. If he lists it on Ebay , I write down the listing number. In any case I appreciated pepi and you coming up with some very workable answers. Thanks again !!! Frank

[papi]

I'm glad to hear you did it well, have many other succeses Frank

[Frank Niro]

Well sometimes things move very fast indeed. If you would like to see where and how the mokume came out please go to Ebay no. 280135807836. I hope a look will be worth your trouble going there. Frank

[papi]

That is soooooooooooooooooooo beautiful...really nice piece Frank. I suffer of lack of words right now...(don't know if i'm saying it right, but whatever, the knife is really beutifull)

[Frank Niro]

Thank you much papi ! I've been at this for a lot more than a couple of years. Still, not everything I make looks good .If I can help you outside of the forum you can email me at niro@telus.net Since I don't go to shows I love to have contact with other knife lovers, especially makers. Frank

[desert.snake]

Hey! I found this topic and would like to ask, did you manage to get a good drawing? I am now trying to etch a piece of mokume, tried 33.3% sulfuric ointment, it gets a good contrast, but the surface looks a little dirty after that. Is there a way for etching that will give a clear pattern while keeping the surface shiny, or is it not about the etching composition, but about preliminary polishing?

[M&J]

Beautiful flashlights! Even that older HDS there.

A combination of steps to experiment with depending on the look desired. I cannot comment on how well the piece was forged as that may also be a factor in the etch. Finishing evenly and that the piece is clean before the etch is an important part that comes in. When I get an uneven etch it usually is that I've not maintained an even finish in those areas. Getting it clean is highly important, Acetone, degreasers, etc.

I finish bolsters to an A30 and etch in a 30% ferric chloride solution. 50% is fairly aggressive depending on ambient temperatures. With the Devin Thomas mokume 1 minute at about 75F is a light etch and where I usually stop. This is just enough to feel some of the ridges between the metals. I'll neutralize then rub it with a polishing paste. The air will naturally work away to reveal the colors over time.

I've been suggested 5% vinegar in a 50-50 mix but I've not experimented with mokume to see how well vinegar actually does.

This is the bolster on my EDC finished as described above. This has been carried for the last 3 years and is the contrast that has resulted.

[desert.snake]

Thank you very much!

Yes, I etched it in ferric chloride, but the result is not very good - it still looks dirty, the contrast is small, it is possible that I kept it in the solution for too long, about a minute.

Then I looked more and found this discussion. http://www.knifenetwork.com/forum/sh...ad.php?t=57076
That site is fortunately still working
https://www.nontoxicprint.com/etchcopperandbrass.htm
There is generally a very good database on many types of etching
https://www.nontoxicprint.com/etchin...ioncontent.htm

I added the required amount of citric acid to the solution (4 liters ferric chloride solution + 1 liter hot water mixed with 300ml citric acid powder (ratio 3:1) = Edinburgh Etch) and heated it to 70 degrees Celsius, held for about 3 seconds, result on the left, on the right with an ordinary solution of ~ 25 degrees Celsius for 1 minute