"Sweating" menuki

[ububob]

At a recent meeting of our local sword club I was showing an older member a set of shakudo menuki purchased at the SF show. He remarked that they had been handled a lot and would benefit from a good sweating. When I questioned him about the term he explained it was a wipe down done with human sweat. Is that as questionable as it sounds or is it a legitimate cleaning technique?

[jason_mazzy]

The only sweating I know of is a heating teqnique used to solder joints................ don't think that would clean menuki well.

[hybridfiat]

Just a guess but, some shakudo is highly reactive 'in the white' and will patinate on contact with sweat.

Do you have some areas where the patina is damaged?

[ububob]

None at all. They are a very rich blue/black.

[hybridfiat]

Sounds dodgy to me. Wash with clean water, dry and a light coat of Renaissance Wax is all Id do

[Curgan]

I might even skip the Ren Wax

[ububob]

...and the question was?

[sanjuro]

I believe the original question was is it wise or even useful to wipe down menuki with a mixture of salt, urea and sebacious secretions with the objective of 'cleaning' them after they had been handled.

It all sounds rather disgusting.........

[ububob]

My thoughts exactly although mine were less erudite.

[Stephen]

its not just sweat, its the oils from your forehead, can be see and at shows all the time, try it you might like the results.

[sanjuro]

Stephen.

 

Far be it from me to doubt your wisdom, but the oils from your forehead are a disgusting mixture of sebum and urea. Both are waste products of the human body and both are slightly acid. The salt content of sweat can vary but that also is acidic Is it really that wise to literally add an etching mixture (no matter how mild) to patinated copper?

 

This ignores the fact that although I love my fellow collectors like brothers, I dont really want to handle their body fluids.

[Stephen]

I dont really want to handle their body fluids.

 

im pretty sure you have more than you care to know.

 

maybe the acid has a cleaning effect.

[Patrick Hastings]

Regular reader here, but I seldom post. I am here to learn. I do however have some experience with patina. I make and work with shakudo and iron fittings regularly.

 

While I would not recommend that everyone start rubbing treasures with human goop. It has been my experience that face oils can promote the rebuilding and preservation of both shakudo and iron patina. Not everyone has the same chemistry though. Some peoples sweat will literally begin to eat away a patina. So I would not let just anybody rub their face on your prize piece (or even touch with there hands).

 

For cleaning? No I would not use face oil for cleaning. Our fingers are actually mildly abrasive to shakudo patina. The Sweat oils will surely loosen up some kinds of crud, but your finger will do little to clean. It is more likely to push layers of dirty oil into crevices and create an eventual build up that will need to be cleaned with a more effective method later.

 

That being said I believe that face oil was likely a common historical application in iron and shakudo patina. It can (from the right person) promote growth where the patina has been rubbed off and is self stabilizing once the patina has grown back. The chemistry happens to have the right constituents to work on variety of metals. It absolutely has restorative ability on the shakudo that I make and work with. While I am decorating a new fresh surface the sweat of my fingers will color the metal quite dark. It's particularly effective when the area is freshly abraded. This is also a requirement for performing Niage, clean oxide free surface responds best, but over time I think a good shakudo will darken with gentle handing by the right fingers. My finger sweat will turn fresh 3.5 percent shakudo purple black in 48 hours.

 

For shakudo the acid and ammonia I suspect are the key components to the process. For Iron the acid and ammonia will promote rust, but there effects deplete rapidly. After many rubbing's what is left is a matrix of iron oxide that is saturated and sealed with the solids left from the dried oils of human hands and perhaps faces. IMO many of the "Good" iron patina you see today are partly composed of human residue.

 

It might sound disgusting, but so many things were like this in the old world. People used ear wax, sweat, feces, urine, Hair, spit, for all sorts of things. It is not uncommon for these things to be listed as ingredients in old formulas for the creation of all sorts of things metallurgical medicinal, or whatever. I have not seen any formulas that require an eye booger yet, but I would not be surprised... I can easily envision a samurai performing regular maintenance to the tiny worn patches on a shakudo Kashira by gently rubbing down with face oil. In addition the oils also lend a wet look to existing patina enhancing appearance. Which might lend to the idea that your "cleaning". The wet look can disguise many blemishes.

 

Regards,

 

Patrick Hastings

Tagane Arts

[christianmalterre]

Hi Patrick! :D

 

Thank You for this excellent answer-it had not ben explained better!

Hope you are fine!(this time it´s me with the flu... )

 

Cheers

 

Christian

[Tcat]

I could swear that somewhere I read a Japanese source that said something about rubbing not neccessarily sweat, but oil from the face (I believe it was oil from the skin on the nose) onto sword nakago and iron fittings as a way to promote formation of an attractive and stable patina...I have no experience with shakudo however.

[Ted Tenold]

As Patrick pointed out, it really is subjective depending on the individual's chemistry. It's not something that can be generally recommended. As an example; I've worked on a lot of swords owned by Iai practitioners. Iai styles vary greatly in techniques regarding contact with the sword during use, "noto" (replacing the sword to to the saya) specifically. A client came to me with his sword and asked me to address the rust that was forming on the sword. He had only just started using it and the rust was in streaks along the mune and shinogiji, and thought perhaps there was something in the saya. I asked him to show me his technique for noto and he did. I pointed out that the rust streaks were consistent with his hand and finger contact with the blade, and that the problem was likely him and not the sword. I removed and neutralized the rust at his request, and he was back again the following week. My response was "go back to using an Iaito". He didn't sweat any more or less than other people. His chemistry simply was not ammenable to steel.

 

So what may very well work, is subject to some careful consideration because it's not a good general approach. Leave patination to the pros.

[sanjuro]

Ted.

Your comment about individual body chemistry is very relevant. We each of us, particularly in the West where our diets vary considerably, have quite different body chemistries which is the product of our diet. A high fat diet for instance, will produce quite a corrosive form of sweat (and other secretions). A high protein diet produces a very different type of sweat. A high alcohol intake will again produce a temporarily different form of sweat, body oils etc. The point here is that with such variance in the reactions that are likely from person to person, and from time to time within the one person, it is unwise to follow these 'old wives' types of home patination and patina preservation. You may with the best of intentions, do more damage than good.

 

I think that perhaps the advice you gave to your Iaidoka friend was well given. The gentleman in question must have had a very sloppy noto technique, since finger contact with the blade surface, as opposed to the Mune of the blade, is usually frowned upon in most Iai schools. You may well have saved him a nasty cut to the web between forefinger and thumb (if he took your advice). :D One wonders also whether he cleaned and reoiled his blade each time after using it.