optimal conservation

[French nihonto]

hello gentlemen, for some time I would like to expose a bare blade in a display case or in a glass bell, but as we know a blade which is not protected by its frame is more exposed to humidity, in nihonto museum the blades are exposed naked. I would like to know what are the constraints in this kind of case. What are the things to respect? optimal humidity rate, frequency of maintenance, positive and negative point of this kind of exposure, ect.
Thank you all

[ROKUJURO]

Maxime,

as long as there is low humidity, there is no danger. The museums have climate control devices/air conditioning for their big showcases. Smaller (air-tight) display cases may be working with chemical air dehumidifiers/desiccants, if these are reactivated regularly. 

[French nihonto]

34 minutes ago, ROKUJURO said:

Maxime,

as long as there is low humidity, there is no danger. The museums have climate control devices/air conditioning for their big showcases. Smaller (air-tight) display cases may be working with chemical air dehumidifiers/desiccants, if these are reactivated regularly. 

thanks for your answer, the difficulty is that I wanted to expose the bare blade and its koshirae below. for the blade the lower the humidity, the better. but for the koshirae it takes a minimum of humidity to nourish the wood. so what is the right balance to keep the blade and koshirae in optimal condition?

[John A Stuart]

In most display cases at the up-market dealers that contain exposed blades and koshirae together I see a bowl of water. I suspect there is a maintenance routine to ensure no oxidation. John

[RichardP]

This is the best hygrometer I can find for the money:

https://www.amazon.com/Cigar-Oasis-Caliber-Digital-Hygrometer/dp/B00JXOKT1O/ref=mp_s_a_1_28?dchild=1&keywords=hygrometer&qid=1611603707&sr=8-28

It’s small, inexpensive, easy to calibrate, and seems to be very accurate.  

 

 

[French nihonto]

thank you john for the info, very interesting the bowl of water, it seems delicate as a process in a small showcase like mine, it would be necessary to find the right quantity to put.
thank you richard for the hygrometer, it looks good.

[ROKUJURO]

Maxime,

in case you want to show both, it is important to have a TSUNAGI to keep the KOSHIRAE as airtight as possible. For a few days you might not need water in the showcase.

[Gakusee]

Well, wait a second here. The bowl of water is for the lacquer and not the blades. The really top end blades are never shown with any water next to them and in fact are safely tucked away in their shirsaya in the back room, away from eyesight. In fact, I will go as far as saying that if you see a naked blade and koshirae with a bowl of water, the value of that “package” is probably in the koshirae. 

[French nihonto]

9 minutes ago, Gakusee said:

Eh bien, attendez une seconde ici. Le bol d'eau est pour la laque et non pour les lames. Les lames vraiment supérieures ne sont jamais montrées avec de l'eau à côté d'elles et sont en fait cachées en toute sécurité dans leur shirsaya dans la salle arrière, loin de la vue. En fait, j'irai jusqu'à dire que si vous voyez une lame nue et des koshirae avec un bol d'eau, la valeur de ce "paquet" est probablement dans les koshirae.

the bowl of water seemed delicate to me. Or go to counterbalance an overly powerful dehumidifier. If the size of the dehumidifictaur is well suited to the surface to be dried, no need to use excess water

[ROKUJURO]

As far as I know, the humidity is necessary for the wooden parts of the KOSHIRAE to prevent shrinking, which would subsequently cause the lacquer to crack and eventually flake off.

[French nihonto]

After a lot of research, in museum conservation articles. the optimal conservation range for wood is between 45% and 55%, for the anecdote the Mona Lisa is preserved at a rate of 55%. For metals the optimum conservation range is between 35 and 50%. So for the case of a conservation of a koshirae with a bare blade the best compromise would be to have a humidity level of 45%.
I have found picture that support this.

 

[mtexter]

This is a topic I never really thought too much about.  The humidity in my house fluctuates from probably 10% in the winter to maybe 60% in the summer, though with A/C it's probably less.  Time to get a hygrometer to know for sure!

[French nihonto]

3 hours ago, mtexter said:

This is a topic I never really thought too much about.  The humidity in my house fluctuates from probably 10% in the winter to maybe 60% in the summer, though with A/C it's probably less.  Time to get a hygrometer to know for sure!

I have never looked into the subject until now, but it is very interesting.
for me at the moment, with the chimney fire running 24 hours a day, I am at 45%, below 40% it is harmful to the lungs I believe.

other photos: (it is still around 45%)

except the last one, which is strange, hoping that it is a malfunction of the hygrometer, because 58% is too much

[John A Stuart]

I see a glass bowl of water in that last pic; to the left. John

[RichardP]

If you’re looking to maintain the humidity at 45%-55% for the koshirae—and the volume of your case isn’t too big—you might look at two-way humidity packs.  Boveda manufactures packs with higher humidity levels (~70%) for humidors, but they also make ones for violin cases and such with a relative humidity in the range you’re looking for:

https://bovedainc.com/wood-instruments-music/

[Gakusee]

Sorry, John, where is the water in the cabinet with Juyo swords?

[French nihonto]

11 hours ago, RichardP said:

If you’re looking to maintain the humidity at 45%-55% for the koshirae—and the volume of your case isn’t too big—you might look at two-way humidity packs.  Boveda manufactures packs with higher humidity levels (~70%) for humidors, but they also make ones for violin cases and such with a relative humidity in the range you’re looking for:

https://bovedainc.com/wood-instruments-music/

I will test it, it seems interesting

[mtexter]

On 1/26/2021 at 11:25 AM, French nihonto said:

I have never looked into the subject until now, but it is very interesting.
for me at the moment, with the chimney fire running 24 hours a day, I am at 45%, below 40% it is harmful to the lungs I believe.

other photos: (it is still around 45%)

except the last one, which is strange, hoping that it is a malfunction of the hygrometer, because 58% is too much

Maxime, that's a beautiful display, wow!  Where do you get a glass case like that, or is it custom-built?

 

[French nihonto]

1 hour ago, mtexter said:

Maxime, c'est un beau spectacle, wow ! Où obtenez-vous un boîtier en verre comme celui-là, ou est-il construit sur mesure ?

 

indeed it is a beautiful showcase, but it is not mine. I hope to have a similar rendering on mine. I will build it to measure. the hardest part is for the glass plate, I would like it to be in one single piece so as not to have an unsightly join

which will hamper the visibility and appreciation of the swords.

[Vagabond]

Great and interesting topic!!!  It would be interesting also a specific topic about how shoud be built a display case ( for dust and  humidity preservation etc)

[French nihonto]

1 hour ago, Vagabond said:

Great and interesting topic!!!  It would be interesting also a specific topic about how shoud be built a display case ( for dust and  humidity preservation etc)

As I build a custom showcase I am confronted with all these problems. And it's not as easy as it seems.

[Gakusee]

Time is money, as they say...... Time (money) invested in researching, designing, procuring materials, building, fitting, etc.... Once you calculate all of that, you realise that you are better off buying one.

 

Mostly, they are not expensive :https://www.accessdisplays.co.uk/cat/glass-display-showcases/wall-mounted/

 

Of course, they could become high-end too: https://en.katana-case-shi.com/product-page/刀展示ケース-漆-urushi-の複製

[Brano]

On 1/27/2021 at 1:12 AM, Gakusee said:

Sorry, John, where is the water in the cabinet with Juyo swords?

at the bottom left could be a shallow ceramic / clay container with water - marked in yellow

[Gakusee]

Sorry, Brano, but this is just a label. I have been to so many dealers in Japan and have never seen water next to blades, let alone Juyo and above blades. 

I have, of course, seen the bowls of water next to tsunagi-holding koshirae, armour, kake, etc anything that has high-quality lacquer. 

 

I know it sounds petty, but it is time we became pragmatic and logical on this topic , rather than venture into wild and romantic hypotheses as to how it might get done, etc. 

 

I cannot count the number of times I have been to the Tokyo National Museum or the NBTHK museum - and guess how many times I saw bowls of water next to swords, or even koshirae or armour ? That is right, never. Even when the NBTHK displays koshirae and lacquer, they do not tend to put water. 

[Japan2112]

I have not seen bowls of water in displays at the Metropolitan Museum in NYC, Boston MFA, George Walter Vincent Smith in MA...

for either  sword blades, armor, or koshirae. I am not certain of their case specifications, and admittedly I may have not been looking too hard at anything but the Nihonto.