Tsuba Yanigata

[Dan tsuba]

Hello all!

 

So, like I stated “I am out of here” on that “Tsuba casting molds” thread.  But I still look at it and there has been an interesting question raised (before and recently) on that thread (I refer to pages 7 and 13 of that thread).

 

That question has to do with tsuba Yanigata.  The resin or pitch type casts made of tsuba (and other objects).

 

Pitch is a type of plastic.  It is a “viscoelastic polymer”.

 

Maybe these tsuba Yanigata were used by the Japanese craftsman as a sort of visual 3-dimensional aid and example to use when they were carving the same design on another piece?

 

They probably would not make another metal tsuba to keep as an example of their work.  Why would they do that when they could sell their duplicate piece?

 

A website dealing with Yanigata can be found here (although nothing is stated about using them as visual aids or examples to use when making a tsuba or other objects)-

 

https://tsubakansho....2020/06/26/yanigata/

 

I have also included some pictures of these “plastic type” Yanigata (previously shown on that “Tsuba casting molds?” thread).

 

Just another interesting question!

 

With respect,

Dan

 

[Ford Hallam]

To clarify, the pitch in question here is called matsu-yani (pine pitch) in Japanese workshops, as it was in the Edo period also. It's mentioned in the Soken Kishō for example.

 

The typical recipe is:  750g Pine rosin ( that's the sticky resin sap with the terpentine etc. removed) , 1000g filler material, traditionally a finely ground fire clay, nowadays plaster of Paris of more frequently used, 50ml of vegetable oil and a teaspoon of carbon powder. I don't think a chemist would characterise matsu-yani or yani/rosin alone for that matter, as a type of plastic.

 

Here's a link to a film I made some years ago showing how to make the stuff.

 

As can be seen it is really quite runny when hot and remains quite pliable while warm. Once cold it can be broken almost like pottery.

 

Worth noting that over time the material breaks down, probably due to a gradual loss of oils etc. leaving the yani  more friable and grainy in appearance.

 

 

[Spartancrest]

Can I ask why fired pottery clay or porcelain was not used to make these models? The Japanese were as renowned for their pottery as their metal work - just curious why they chose something that breaks down with time as Ford has pointed out, compared to something that could stand the stress of time? 

[1kinko]

Probably because clay shrinks and distorts as it dries, particularly flat pieces of clay. Plus not every metal worker had a kiln nearby. I've been using the same patch for about 10 years and while it does get more brittle with constant remelting, it works just fine for holding the metal in place- just requires more pressure to break your piece out.

[Ford Hallam]

Dale, I think it was probably a number of factors at play. Matsuyani was readily at hand, so it got used, we see evidence of this sort of adaptation of materials in patination too. Half the kitchen cupboard seems to have been tried at various times 

Matsuyani is capable of delivering a very fine imprint in the first instance and while it does break down over time I reckon for the needs of the people making and using them back then it was more than adequate. As Darrel pointed out clay is prone to distortion but I'd add that the fineness it may have been capable of reproducing might not have been quite good enough to capture tosogu detail.

 

My own feeling is that they were records for the studio and most likely used to train apprentices in the finer points of metal sculpting and the style and technique of a particular studio. A bit like the plaster models used by the classical drawing and painting schools beginning in the Renaissance.  

The faithful adherence to and absorption of the school or studio style was at the heart of traditional training after all. 

[Spartancrest]

Thanks Ford, that makes perfect sense. I suppose the material could also be 'corrected' if there was a small fault or some damage by applying a little heat? Something you can't do with pottery or porcelain. 

[Dan tsuba]

Thanks, Ford, for the information.  So, these Yanigane were probably used as examples or models to make the same designs on tsuba (and other pieces) or used by apprentices for training purposes to learn the technique of a particular studio (or school).

 

Which brings up another interesting question.

 

How were these Yanigane made?  Was the completed metal piece pressed into soft clay (or casting sand) and then the matsu-yani (pine pitch) was poured into the clay (or sand)?

 

Or could the matsu-yani itself be used to make a mold when slightly hardened and then a more liquid state matsu-yani poured into that?

 

Not important, but just interesting!

 

With respect,

Dan

[Ford Hallam]

Hi Dan

 

glad to offer what I can.

 

As to how it was used. My understanding was that a suitable layer of fine damp clay was first prepared on a board. A fine dusting of soot was then applied to the intended model, the finished tsuba, menuki etc.

The metalwork then pressed into the clay and it all allowed to dry out a little bit, perhaps over night. I'd assume this was all done before the very final polish and patination processes.

 

Then, after the metal work was removed the imprint was filled with very hot/fluid matsu-yani allowed to cool to properly solidify and then removed. I've seem some models thus produced but with the addition while still very hot/fluid, of a backing of coarse cloth as reinforcement.  

 

Using hot pitch to create a mould directly from the metalwork is unlikely as one of its most useful features is precisely its tendency to stick to metal like the proverbial .... to a blanket! . 

[Dan tsuba]

Hi Ford,

 

Thanks for your expertise on explaining the process.   Much appreciated!

 

With respect,

Dan

[Spartancrest]

   This paperweight could never be confused with a Yanigata but still a pretty little thing  JMO