There are many ways to skin a cat. Most work fine. My method for finishing damascus depends on the original materials it is made from. Most of my work is 15n20 or L6 with a high 10 grade steel 1070 10 80 or 1095. If I am going yt heat blue the finished blade I always put in some 52100 to support the edge after the hot draw. Most of my blades are etched from about 800 to 2000 grit finish depending on the desired result. Some are mirror polished. We will get to that in a minute. I use ferric cloride and distilled water at about 50 50 mix . I never use tap water containing clorine . It will degrade your etch very rapidly. I also never leave my steel in the ferric over one minute at a time. I clean every minute with clear water (no clorine)and 2000 grit paper The black oxide acts as a resist and muddies your etch. I finish by using somthing with amonia to stop the action of the ferric . Always out side my shop. If the pattern is deep etched I give it a quick touch on a soft buffer then put the blade in a sonic bath to get rid of the compound. If the blade is to be heat colored the brighter the finish the brighter the resulting color. If you are making damascus out of steels lacking nickle use warm sulfruic or dilute nitric acid with the same cleaning tecnique. Be careful you only have one set of eyes. The more perfect the welds the shallower the etch. Heavy etching is a sign of poor tecnique . Again these are my methods developed over thirty years, I have made most of the mistakes several times.
I learn somthing new every time I meet a new maker. Take time of keep you steel clean as you etch . It makes a great difference in the final result.

Everyone..........pay attention to what Steve says! Wise words from one of the top makers in the world today!

Steve,
Thanks for the info!
How long long does it take to etch (on the average) a blade of 1084 and 15N20 using your method?
I always feel "lucky" when I get a good etch, and really appreciate this thread. I have wondered at times with blades from the same piece of cable, why they etch differently for me when I would swear I did everything the same. I am going to use this method as soon as it rains. Thanks!

Dont wait for rain just use some distilled water . any time you use processed water cleaned with clorine it will slowly degrade your acid bath. Even if you just wash your blade with it the clorine will migrate into your bath with each dipping . Heat treatment will also affect your etch . Decarb is also a factor especially in cable. Ferric needs to be diluted at least 50% from the radio shack form to get the cleanest etch. I normally take 15 to 30 minutes to etch a blade. . I just put the clean blade in a minute at a time them scrub it with 2000 wet and dry in clear water then repeat the process until the depth of cut is achived. You can let the ferric cutfor a longer time but you will not get as nice a result. The 2000 help keep the raised areas polished . If I want a deep etch I use a glass brush from an artists supply to clean the deep areas of the blade.

Great info, thanks.
Have you ever used vinigar to dilute your feric? I am going to be etching some Thunderforged damascus (1095 & 01), and I read to use 50/50 vinigar and feric to etch. From my schooling I thought vinigar was a base and would neutralize an acid.

Thanks
Jeremy

Thanks Steve, I'll see if I can get that to work for me. I've been using ferric about 7 to 1 with distilled (rain) water, but I've been cleaning in between with regular tap water, sand with 600, rag wipe, back into the etch. I've realized now that I really don't have a system, just keep etching until I like it. :rolleyes:

From my schooling I thought vinigar was a base and would neutralize an acid.

Thanks
Jeremy

Jeremy you shouldn't have to worry, vinegar is acetic acid if I remember correctly hence its reaction with baking soda, a base. Did you ever make the little volcanoes? My moms kitchen took forever to get the vinegar smell out of it, I probably went through 2 bottles of vinegar and 2 boxes of baking soda playing around with that stuff.

I'm under the impression that Ferric Chloride is a base, not an acid. There was a thread about this a long time ago, but I think it's lost in cyber space on the old forum.

FC is not acidic per se...however, it enables an acidic response to occur.

For what it's worth,
I've been using 1 Part FC, 2 Parts Distilled water, with 1 Part White Vinegar with great success...

The rest of my etching process is relatively similar to Steve's...Except that after the last "dunk", I drop the damascus into boiling disitilled water and baking soda for 10 minutes. Helps to set the last round of black oxides (I prefer a deep etch with lots of contrast). Then a quick squirt all over with acetone to instantly "dry" off any water.

Oh yeh...Like Steve, I prefer to finish off with approx. 2000 grit paper. I use 3M's polishing papers (The blue and then the pink for this particular application)...They go from approx 400 grit all the way to around 7000 grit and are just the "cat's meow!" :D


Dennis Greenbaum

Yeah Baby! :smokin

If someone wants a more technical explanation of ferric chloride's acidity, try this:

www.artmondo.net/printworks/articles/ferric.htm (http://www.artmondo.net/printworks/articles/ferric.htm)

Thanks for that Fitz.

Good info, and written in layman's terms so that even I could understand it. ;)


Dennis Greenbaum

Yeah Baby! :smokin

You're welcome. Seemed like a good, understandable explanation.

I am always open to new ideas. I will try the vinigar next batch out. Even old dogs can refine tecnique. The indo china bunch use formic acid to etch kris blades . That is the same acid ants use to set us on fire. Cant imagine milking that many ants to get a pan full. Does any one know if it is comertially available? Hope they get a spell check on this soon.

Steve, formic acid is certainly available as a laboratory reagent; that much I know. You could try Aldrich Chemical or VWR Scientific if other sources fail. They require a business licensed address to ship to as a destination is the only hassle.

The addition of vinegar into the mix is going to increase the acid concentration obviously, and thus the rate of etching. This will probably translate to the higher alloy steel also getting etched more than at weaker concentrations given the same timing as no acetic acid in the mix. The actual differences may be negligible in terms of steel loss, but may provide some desirable variation in coloring.

Another possibility would be to mix table salt and vinegar, which would form a small bit of hydrochloric acid in the mix; this would afford another simple home etchant without having to keep muriatic acid around the shop to rust tools when the gas leaks out of the bottles. Chlorides of course attack steel very aggressively.

Actually, if you think about it, my formula is less acidic.

Instead of the FC being 1 to 1 with water, it's now 1 to 2...so the FC is less acidic.
The white vinegar is low acid as well.

I've done a lot of experimenting with both FC and Water,...and FC, Vinegar, and Water. I've tried different times for immersion, I've tried heat coloring after etching, I've even tried things like applying Van's cold gun blue after using the "pink" (3 micron) polishing paper on the etch (works really great by the way,...wonderful, subtle blue patina...only works on carbon damascus).
That's what I used on this knife (thanks to Rich Slaughter for the nifty photo) ;)...

http://a6.cpimg.com/image/AC/37/37800876-5dcb-027E01C3-.jpg

I don't claim to know all the reasons why, but my last couple of etches have been my nicest by far, using the formula metioned earlier...1 Part FC, 2 Parts distilled water, one Part White Vinegar. It is a slightly slower etch because of the reduced acidity. My first "dunk" is 5 minutes. Each succeeding "dunk" is for two minutes. (BTW- The distilled water gets heated first in the microwave).


Dennis Greenbaum

Yeah Baby! :smokin

I am speaking of using vinegar instead of water as part of the diluent. FeCl3:H20 1:3 will be less acidic than FeCl3:H20:HOAc 1:2:1. Vinegar has a decent amount of acetic acid in it, typically 5% for American white vinegar. The concentration varies based on the type of vinegar.

I am trying not to get too technical, here. This is more complex than simply talking about acidity as hydrogen ion concentration (pH). The inclusion of chlorine as chloride ion in an acidic environment brings another player to bear in the equation. Equivalent concentrations of two strong acids (measured as "normality", a chemical term which is used to make concentrations comparable), such as hydrochloric and sulfuric acid, will produce radically different etches on steel, despite the fact the hydrogen ion concentration is the same. The difference is because of the chloride ion versus sulfate and it's effect on the steel.

I'm not trying to get into a chemistry argument here, simply offering a bit of what my professional training provided. I've etched a wee bit of damascus, too, Dennis, having first made my own in 1987. I'll just buzz off and let you guys discuss it. Sorry to have intruded.

Fitz-

You're informed and insightful responses are never an intrusion...

FeCl3:H20 1:3 will be less acidic than FeCl3:H20:HOAc 1:2:1.

Of course I agree with that statement. FC mixed with 3 parts water is certainly going to be less acidic than with 1 part water (as Steve is currently using). When Steve said he was going to "try the vinegar" I took that to mean in my ratio, or something similar. Am I wrong about my formula being less acidic than Steve's current mix of 50/50 FC to Water? If I understood it correctly, FC becomes acidic when mixed with water. If there's less water and in it's place a relatively mild 5% white vinegar, wouldn't that net out as less acidic?...or does FC turn acidic when mixed with vinegar as well as when mixed with water?

In other words, my response was based on my thinking that we were in fact discussing going from
FeCl3:H2O 1:1 to FeCl3:H2O:HOAc 1:2:1 NOT FeCl3:H2O 1:3 to FeCl3:H2O:HOAc 1:2:1 as you stated above.

(Now please don't go getting too technical with your response, chemistry was never one of my strong suits)...I'm already in about as far over my head as I can get. ;)


Dennis Greenbaum

Yeah Baby! :smokin

Boy, all this talk about salt and vinigar is making me hungry. I make up a sause with salt, vinigar, and butter to put on chicken and grill it. All those letters and numbers is making my eyes hurt. I took physics, not chemistry.

Serousily though, this is a great thread, I will be doing some experimenting soon.

Jeremy

Dang, I just managed to accidentally delete a much longer response as I typed with a bunch of tech mumbo-jumbo. May be for the best.

I'll just say that the more I think about this etching solution, the more complex it is. Iron can have more than one oxidation state, and our etch solution will become a complex mixture over time. It may also absorb either oxygen or carbon dioxide from the air, altering it further. The presence of the acetic acid will change this balance, in addition to reacting with the steel on it's own.

I have a number of experiments in mind to make different mixes, see what happens as they stand, and see how they etch steel with time. I'll also jot down some chem equations and try to understand this at a bit more technical level. If I still worked in my laboratory, I could tell us a bunch. Alas, those days are gone. However, if I learn anything I'll report back to this thread.

Meanwhile, I'm sorry for my "take my ball and leave" attitude. For reasons not needing public discussion, I am noticing a certain quickness to anger lately. It is not appropriate on the forums, so I am going to sit back and read and not post until I have a better attitude. Actually, I HAVE been laying back mostly, but this thread interested me. (I was pretty proud at my restraint the other day when Les jumped yer butt! :eek: I'd have gotten banned if I'd said what I wanted to!) Now I know I should have stayed shut up here, too.

Nonetheless, if I figure out anything worth mentioning on this thread, I'll post. Take care, folks.

Mike-

I for one never even noticed any "take my balls and leave" from you...nor did I pick up on the slightest hint of anger coming from you. As always you've been nothing but a great contributor to this thread. For that matter, I'm not sure that anybody was ever disagreeing with anybody here...just different thoughts and opinions. Seems to me the crux of the whole discussion has been all about, as Steve puts it, "there's more than one way to skin a cat." ;)

Looking forward to hearing how your experiments turn out...should be interesting for all of us.


Dennis Greenbaum

Yeah Baby! :smokin

Fitz:
If you take your ball and leave, come come on Down to "Gods Country"!! Id love to pick your brain a bit!!! :p

But seriously, Im wondering what would be gained , (or not gained) by using diffrent etchants on the same piece? As an example, a heavier, or stronger etchant to give it depth of cut, followed by a weaker etch to bring out the coloring and contrast in the steel?
Would it make any diffrence??

God Bless
Mike

If storing acid is a problem, I found acrylic canisters from of all places, Wal-Mart, store the acid quite safely. They have a good seal at the top, a strong metal latch on the out side, and since they are thin and tall they a great help for conserving acid and I can hang the knives completely vertical. I work mostly with Damasteel that I buy so I always use muriatic.

A question I have is about the vinegar. I though the vinegar used was at a much higher concentration (I think Gene, who was telling me about it) was about 25% or higher. It's all I think Gene uses to etch his cable.

Jim

Maybe I've just missed where you guys have said this, but why exactly are you using vinegar with the acid? Does it darken the etch, or make it etch faster, or what?

I had read about adding white vinegar to the etchant in some other knife forum, quite some time ago...for some reason the idea stuck with me. When I tried it out as described in an earlier response, I wound up with the nicest etch I had achieved thus far. When used as described, I get really nice, deep, crisp lines with lots of contrast.

As to why or how it works so well when used in that combination, using the described protocol?...beats the hell out of me. :confused: But I sure like the results! :)


Dennis Greenbaum

Yeah Baby! :smokin

Dennis I read somewhere that the vinager helps keep the bubbles that form with the ferric chloride from adhearing to the steel and muddying the etch.
Don't know if there is any truth to it but something about it works.