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Ford Hallam

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Ford Hallam last won the day on June 29

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  1. It looks to me that the filler material that was used to secure the dragon and ken element to the nanako ji-ita is a matsuyani mixture. Essentially pine rosin and fire clay. It's very runny and sticky when hot/warm and rock hard when cold. I've encountered it many times when restoring Meiji period pieces that were constructed out of many components. When it was fresh it would have been much more tough and resilient but over time the remaining oils and resinous ingredients evaporate leaving the mixture characteristically dry and friable, like this. The use of matsuyani to stick decoration onto a kozuka is definitely not an Edo period norm I have to say I'm a little concerned about recent suggestions here on the NMB that vinegar, salt or other such potentially corrosive solutions be used in the cleaning of tosogu. Unless you know pretty well what you're dealing with in advance and know how to put it all right when you're done you may well be opening a can or worms/Pandora's box of trouble.
  2. I've seen entries in various dairies of samurai doing tours of duty in Edo where they list monthly expenses etc. Two I can think of off hand were regarding a saya repair, to the urushi, and the other a rewrap. Rewraps were apparently needed yearly. The inference being that it simply wouldn't do to be wearing a sword as a retainer that wasn't kept in decent condition, and I'd suggest that'd include worn patina. A worn iron patina would also be vulnerable to fresh rust which could soil one's kimono too. So it seems reasonable to think that tsuba and other fitting would have been periodically touched up.
  3. Hi Glen I can't claim any credit for correcting the Silver sulphate typo, I didn't see it at all I was only focussed on the black stuff Your explanation that silver sulphide forms a "network solid' is actually further helpful in going someway to explaining how this conversion actually migrates away from the source silver as on the tsuba you show. I wonder if this is a sort of flowing structure? It does actually come away from the iron ground very easily so It doesn't seem to be significantly bonded at that point of contact. The silver sulphide on the actual silver, on the other hand, is quite strongly bonded. I tend not to use any sort of abrasive methods it removing it, because of the delicacy of the work mostly, so I use a chemical solution to break down the sulphide that is very gentle in its action. I won't mention what it is for fear of unleashing DIY restoration armageddon.
  4. Colin, those latest images are really far more revealing. I can see what you mean with respect to there perhaps being some indication of structure in the iron. If you'd like to send it to me, I'm in Dartmouth, I'll remove all of the rust/corrosion product safely, photograph at high magnification and resolution the resulting surface and then re-apply a suitable patina. I'll do this for free and post the images here so we can all see and learn more, and you'll get a much better tsuba back to boot. If you'd like to take up my offer message me for my studio address etc. And having read with interest the superbly detailed chemical and metallurgical discussions this thread has engendered I must add one last bit of info myself. As I think we've now established, and contrary to Bavarian school of metallurgy dogma , silver does indeed covert to a corrosion product, namely silver sulphide. What I'd like to add is some real world experience that is directly relevant to tosogu and may be of interest to fellow students of the art. As a restorer I must have worked on at least a couple of dozen of bronze vases that featured fine silver wire inlay. Typically the wire was around 0.5 mm in diameter and once inlaid it had been polished flat. These were mostly Meiji period pieces so around the time I worked on them perhaps 90 to 100 years old at most. Without exception the silver wire was black, unless someone had previously buggered around with them in which case the bronze patina was knackered too. Sometimes the black 'scale' (silver sulphide) had grown so thick that it'd started to flake off. This flaking happens because the silver sulphide is very brittle compared to the underlying silver. Changes in temperature and the resulting differing degrees of expansion and contraction of the silver and sulphide layer causes a break where they interface. The newly revealed fresh silver appears a dull white at this point and is quite rough in appearance, almost stony. It's quite a fiddly and time consuming process to restore a degree of polish to this corroded silver. With the silver sulphide removed what was once a smoothly polished surface now has a very clear groove in it that you can actually catch your finger nail in. Consider that the wire was 0.5 to begin with ( an average based on those pieces I've restored and had to re-inlay) , some thickness is lost in the inlay and polishing process so we can estimate perhaps a depth of around 0.35 remaining. this is in fact what I've measured myself when dealing with tiny fragments that have fallen out. What is remarkable is that the action of the hydrogen sulphide in the air in converting the pure silver (it's almost always fine/pure silver in Japanese inlay work) into silver sulphide has easily consumed half or more of the original silver in 100 years. Sometimes actually all of it. This is also why we find that gold nunome-zogan tends to survive more frequently than silver numome-zogan. Even on the same piece of work the silver will inevitably be more fugitive compared to the gold. This is a very real problem I've had to deal with countless times. Higo tsuba collectors will know this well too I suspect, tea inspired wabi-sabi aside those Jingo tsuba rarely have much silver left. Some applies to Hizen and Jakushi works. For reference the foil used in this type of Edo period nunome-zogan is generally around 0.02mm thick, that's about as thick as a sheet of standard 100 gsm printer paper or 20 microns thick. In the Jewellery industry the accepted standards for gold plating is 0.5 microns (or more) for standard plating and 2.5 microns for heavy (sometimes termed Vermeil, from the French term for mercury gilded bronze) plating. And 20 microns of fine/pure silver (jun gin) sometimes doesn't last 100 years on a tsuba whereas gold that thin can survive in wet acidic soil for thousands of years virtually untouched. Well, the gold survives, naturally, but any additional copper or silver in the alloy is inevitably attacked and is lost to the gold artefact. This leaching out of the non-gold elements is what causes that characteristic frosted rich fine gold appearance of ancient archeological gold.
  5. I've been bothered by this muddying of the waters regarding corrosion and rusting. The actual physical and chemical process whereby iron and steels is converted into any of the corrosion products I listed as 'rusts' in my previous post is called, by real metallurgical scientists, the corrosion process. We can have our own, tsuba/tosogu specific understandings of patina etc. and personally I need to make that distinction sometimes because that's a big part of my own particular work. But : The action on the metal is 'the corrosion process' and the result of this process is 'the corrosion product' or rust. Sometimes this rust can be made into a stable and attractive finish we enjoy as patina.
  6. I didn't suggest they were interchangeable at all. Nice summation of exactly what I wrote; "Corrosion in fact covers the damage caused by rust, and that's really what we're looking at here. It is perfectly correct to speak technically about a corroded steel structure and to distinguish it from a merely rusted one." On zinc and lead it'll be white. Silver is reduced to a black silver sulphide, as described below. The corrosion products that occur on iron and steels appears in a range of reddish, brown to black colours and is known as rust. Some of the blue and green corrosion products you refer to do contain some oxygen but those particular compounds are generally more complex than simple copper tin zinc lead alloys and oxygen. Copper chloride is a turquoise colour CuCl2, no oxidation involved. Copper Nitrate is a good royal blue, if it was only oxygen doing the work the result would be either black or brick red but the nitrogen changes things. Cu(NO3)2 Not all corrosion is in fact a result of oxidisation, as described above. Take silver as an example pertinent to tosogu, it's a silver sulphide Ag2S that forms on the surface and gradually consumes it. I ought to add that the broader topic of corrosion covers much more than only metals and involves many more complex process other than merely oxidisation. The scientific literature on rust lists (at least); 12 varieties of Iron oxides and hydroxides 3 varieties of iron carbonates 9 types of Iron chloride 12 Iron sulphates 4 Iron phosphates and 10 Iron carboxylates and cyanides. These all have their own particular colours and microscopic structures. The colours range from yellows, ochre, green, a wide range of browns through to red, greys and black. I believe it's the interplay of various specific 'rusts' like these, in a patina, that results in the characteristic colour and tone of certain Tanko school's tsuba. What has been especially interesting to me is that traditional tsuba patina recipes and those I've developed from the original sources reflect very well almost all of those varied and complex compounds we generally lump under the generic term 'rust'. Rust is so so much more than Iron oxides. Stable iron patina are invariably complex and multi layered compound structures produced by complex and sophisticated process that were developed over many generations through trial and error. If it just looks like crusty red iron oxide the patina is long gone. Well that'll teach me to throw in my tuppence worth... but as chance would have it I was in fact writing on exactly this topic of corrosion and ferrous patina last evening.
  7. Alban, this is a superb piece, I can see why you love it.
  8. thank you Brian, for your endorsement. in case my meaning was unclear due to my typing error; 'Despite apparent serious surface corrosion there is the evidence of laminar structure that would inevitably be present in hand wrought pre-industrial steel/iron.' ought to read Despite apparent serious surface corrosion where is the evidence of laminar structure that would inevitably be present in hand wrought pre-industrial steel/iron? Dan, I'd have to disagree with your suggestion that this is a rusted, not a corroded, piece of material. Corrosion in fact covers the damage caused by rust, and that's really what we're looking at here. It is perfectly correct to speak technically about a corroded steel structure and to distinguish it from a merely rusted one. Structures made from Corten steel, for example, rely on the formation of a rust coating to protect it from further rust penetration that would lead to corrosion and mechanical failure. Perhaps a simple and more familiar example might clarify; the patina we admire on ferrous tsuba are composed of rust, albeit in a fine and stable state. Once that stable rust patina is disrupted and 'goes live' it is actively rusting, and causing corrosion, ie; the degradation and breakdown of the metal's surface and eventually structure. As for the time it might take for a surface of steel or iron to exhibit the sort of texture this example shows that would depend entirely on the conditions it was kept in or subjected to. It's perfectly simple to recreate this degree of 'apparent' corrosion in a few months. Quicker if you were to use a little bit of electrical current to speed things up a bit. And for anyone who really wants to go down the rabbit hole of pre-industrial ferrous metal structure and the effects of time and corrosion etc. these four books are the most frequently thumbed on the subject in my library. There's about 1300 pages of solid material in there. regards all Ford IMG_0990.HEIC IMG_0992.HEIC
  9. For what it's worth this is what I see... Despite apparent serious surface corrosion there is the evidence of laminar structure that would inevitably be present in hand wrought pre-industrial steel/iron. This sugests that the tsuba is made from an homogeneous plate of material, my intuition suggests mild steel. The second point, already implied by my first observation, it that the very evident pock-marked corrosion surface is absent from the inner walls of the sukashi. We also see still crisp edges around the seppa-dai and, for me, unconvincing tapering out of the texture in to the seppa-dai itself. The kozuka atari is a bit too curved too to be a reasonable fit alongside a kozuka back suggesting a lack of awareness of its realy practical function and meaning. My feeling is that this is a modern-ish hobby piece worked up to look older than it really is.
  10. Soren, I appreciate what you wrote ; "I feel I have made a bargain in both tsuba and the acquired knowledge". I think that's the only sensible attitude we can adopt if we really want to delve into this vast subject. It really is an ongoing refining of seeing, feeling and understanding, but it is immensely satisfying :-) And thank you Curran, for your kind appreciation.
  11. Ignoring the mei for a moment I'd begin by simply assessing the work alone. The ground is a fairly generic type and actually one of the quickest to apply, so perhaps not chosen for any aesthetic reason but merely efficiency. The kata-kiri work of the tree branch on the reverse is very dull and not at all anything very expressive or even particularly interesting. It feels almost like an afterthought to me. The kata-kiri on the front is similarly uninspiring and the rock and leaves looks very much like those seen on Yokoya work, not Nara school. The base of the tree, on the other hand looks like it draws its inspiration from Hamano work but is also indistinct and lacks any real presence or boldness that the subject ought to suggest. It's the anchor of the composition yet is a bit messy and poorly defined. The figure is competently carved but is it suggestive of the hand of one of the great masters? The face is appealing with its gentle expression and there are some pleasing shapes in the hands but as a flat profile image of the head it feels a bit basic, something any properly trained maker of the period would have been capable of. Great masters are so regarded precisely because their work does go beyond merely competent so as to suggest far more feeling and subtlety. To my eye this tsuba is not of sufficient quality to be considered the work of a top ranked artist in this tradition. But this is only my opinion, other eyes may well see things differently. regards Ford
  12. As to the authenticity of your menuki I'd say they are fairly convincing but to be super critical perhaps just a little messy in the way the individual grains have significant metal 'smooshed' between them. On that point alone I'd be hesitant. A decent example none the less.
  13. If you're interested in understanding more about nanako and its obvious connection to the millet technique this three part series on nanako might be useful too. In part three I discuss a nanako punch that has a hexagonal outer form, which you can see traces of on your example.
  14. Hello Tlognaws You may find this film of the making of Tomei style millet of interest, the millet work itself begins at 7:40
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