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Rokusho / Cupric Sulfate Source (ReactiveMetals - no go)

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Having trouble with sourcing a small amount of Rokusho and Cupric Sulfate.


ReactiveMetalStudios (cited as 'the palce to go') is not answering phone calls or emails. They also have an outdated message on their answering machine from Christmas.


Does anyone know where I can get the means to patina some shibuichi?



I think I am going to do a posing of a WIP of mine. First time casting ... first time experimenting with alloys. I have been a lurker here for
quite a while. You guys are very helpful.


I am doing a 'mini anvil' chess set. White peices are 75% silver 25% copper. Black peices are 25% silver 75% copper (shibuichi). Add em up you have a set containing 1/2 silver by weight :). I am casting them in Delft Clay. The peices weight from roughly 10-30g each.


What I want to do is get the Shibuichi peices (which patina like a dirty penny on their own) as dark as possible. Super clean they can sometimes
be difficult to distinguish from the 'White' peices.



Thanks for your help guys.



Edited by George C. Keller
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First off: Super Cool!


As near as I can tell, Cupric Sulfate = CuSO4 = Copper (II) Sulfate = Root killer from your local hardware store. I'm not sure how pure you need, but it comes in about 99% pure crystalline form that dissolves well in (warm) water.


This one says it is 99% CuSO4. http://www.lowes.com/pd_408173-531-ZROOT24_0__?productId=4383191&Ntt=copper+sulfate&pl=1&currentURL=%3FNtt%3Dcopper%2Bsulfate&facetInfo=

Had to go to their website to find that out though. http://images.zepcommercial.com/english/Root-Kill-English-MSDS-ZROOT2.pdf


Warning that not all copper sulfate is Cupric (CuSO4), some may be Cuprous (Cu2SO4). I have no idea if that matters for what you are doing.


Can't help you with the Rokusho, but I know others can.

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Jerrod, thanks for the links. I will check that out. I think the recipes that I have seen mostly call for a 1:1 combination of Rokusho and Cupric Sulfate. So I may not venture to use one with out the other. Your feedback is MUCH appreciated tho - and if I can only find rokusho now and go to my local Lowes I may be good.


Jesus, What about the vinegar and SALT makes this patina? Would you also boil it? I ask because I remember as I child I learned on Bill Nye the Science Guy you could clean pennies using Salt and Vinegar. Then you would use baking soda to stop reaction. I recently used this method to clean my peices that I found contaminated with fingerprints (the shibuichi ones really stain). It worked well. I THOUGHT it worked b/c vinegar is acidic - like a pickel - and the salt is used as an abrasive. How would this work as a patina? I would have assumed it would have the opposite effect. Interesting!


would mixing the Lowes cupric sulfate and this salted vinegar turn into something ... well ... else?




does anyone else know of an alternate source for the real thing? I dont need much - I think enough for one solid batch.



Thanks all

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Ganoskin has recipes for rokusho-like patina solutions: http://www.ganoksin.com/borisat/nenam/shakudo.htm


I have only had limited experience with these solutions and rokusho in general. You can obtain copper acetate a number of ways, but the simplest from a home chemistry standpoint is to mix copper carbonate (from your local ceramics supply place) with vinegar. You can also produce it with a solution of vinegar and hydrogen peroxide and metallic copper, but I've personally not done this, only seen it on Youtube, etc. If you cannot access a ceramics place, it may be the method you want.


Edit: I believe the method Jesus is referring to is not using the vinegar and salt itself, but the precipitate leaving the mixture in a copper vessel would produce. An old method of producing verdegris (western rokusho) was to bury copper with vinegar, the resulting patina would consist of copper acetate, carbonate, and chloride, depending on the exact method and proximity to the sea.

Edited by Tyler Miller
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Also, if you can't get copper sulphate in the form of root killer or algicide (it's illegal for those purposes now where I live, I believe), you can get it at the drug store. There are usually two grades available, both pure, but one will have USP attached to it, meaning it's medical grade, get the other one, it's much much cheaper, and just as pure for your purposes.


You won't find cuprous sulphate--I've never come across it. The blue-green stuff is copper (II) sulphate pentahydrate. Anhydrous copper (II) sulphate is white--producing it was a grade 10 science project for me :).

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I was not very clear in my description. One of the most common methods of patina in Japan is called niage. For this patina you mix rokusho and cupric sulfate in varied proportions and concentrations.

As Tyler said, I suggested a simple method of approximating the rokusho component of the niage patina. What I described is called vergigris in Western terminology. The composition of verdigris is variable and could be copper acetate (if vinegar is present) which is mainly green in color or copper chloride (when sea salt is in the mix) or copper carbonate and other copper salts in various compositions. If commercial rokusho is not available to you, verdigris at higher concentration than the recommended commercial rokusho solution can closely match the resulting patina. I am not aware of what the exact composition is for the original Japanese rokusho or the commercial rokusho. I have been most impressed with the rokusho made by Reactive Metals Studio which is the one I have used myself.

Enjoy life!

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I recently made some home made rokusho loosely based on the Ganoskin method. Here is what I did:


Took 3% hydrogen peroxide and soaked some copper bits in it under low heat. This creates a copper hydroxide salt.

Added vinegar. The hydrogen ions in the acid combine with the hydroxide ions to make water and the then the remaining mixture is copper acetate.

Take the same copper bits and add hydrochloric acid (muriatic acid). This makes copper chloride. Be safe and all that.


Now I dried the solution and collected the crystals for use but you could use them right away if you want. To do so I'd try the following:


3 parts copper acetate to 1 part copper chloride. Add some CuSO4, warm , dunk and see what happens.


I got really good color on copper using this. It looks just like the niage patina in the books. However, the alloys like shibuishi and shakudo are supposedly a lot harder to get traditional results with using homemade rokusho.


Good luck!



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For quick and dirty, I use Birchwood Casey Super Blue (cold gun blue), probably available in a hardware store or gun shop near you. Clean metal, paint on with Q Tip, wait a few minutes, wash off with soap and water. Lather, rinse, repeat as required. Cut back lightly with 0000 steel wool for highlights.


Not anywhere near the traditional Japanese procedure, but darkness will result.



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Appreciate all of your comments and suggestions.


I HAPPENED to have Birchwood Casey Super Blue in the house and performed a sample test with my 'rook'. [ GOOD IDEA TOM, didn't know that worked on Copper! ]


I was at first not very pleased with the results - but then leared a lesson about cleanliness and it being next to godliness...

After some patience with about 50 Q-tips, some denatured alcohol and the cold blue - I had the back row (non pawns) looking pretty cold and pretty BLUED


I will post a picture of the results w/ the Birchwood Casey.


I TRY to do things the OLD way when possible. I feel really rotten about taking this way out. But I am really pleased with the results... and I dont know if I would be able to keep these pieces clean enough to produce the desired effect with Rokusho/Cupric Sulfate Daiken Radish etc. (pieces being so small and my fingers *seemingly SO LARGE)


The color after a few coats and washing is a very pleasing deep deep blue almost black. The coating is very light and can be rubbed off by steel wool or even a stiff plastic brush. I do not think this is at all similar to the way the 'nautral' Rokusho patina would react....


BUT I am happy with the current results. At least - that is what I will tell myself until I become dissatisfied, scrub down to base metal and take on again at a later date. For now I will photograph tomorrow or when 100% patina'd for the community and for those who have so generously commented.

Edited by George C. Keller
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On the blueing topic, cure them in oil for a few days, (Birchwood-Casey also produce this) or linseed should do, as to finger prints, latex (doctors gloves) work rather well!

To become old and wise... You first have to survive being young and foolish! ;) Ikisu.blogsot.com. Email; milesikisu@gmail.com mobile: +27784653651

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Update to all - Reactive Metals contacted me and the are indeed still in business. So I can indeed purchase the 'original' Rokusho / Cupric Sulfate raw materials.


That being said, I did end up bluing 1/2 of peices last night with Gun Blue. I will finish the other half hopefully this evening and then show the before and after.

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Here are a few more pictures before and then a little more than 1/2 way into the process.


As you can see, the peices really darkened up quite nicely using the Cold Bluing. I don't know yet if the patina that formed will have enough 'wear resistance' yet. That I will comment more on as time progresses.






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