Chemical treatment of a chemical polish?

[Caracal]

What does it look like if a sword has been subjected to chemical cleaning of a chemical polish.

What are the clearest signs? How can anyone avoid being fooled by it.

There are many swords out there at auction companies and many want to sell.

 

// Robert

[16k]

For me, I’d say the Hamon will look flat. When you look at a Hamon, it varies in intensity according to the way you light it. An etched Hamon will look very white and flat. It will be seen whatever the light you use. Also, very often, the Hada will look conspicuous and enhanced., or on the contrary, washed out.

 

pictures would help.

[Dave R]

A good article on the subject here..... http://www.ksky.ne.jp/~sumie99/acid polishing.html

[Caracal]

Thanks for the reply.

 

What can you do if you discover that someone has polished the sword with some chemical and not so bad. Can it be sent for polishing so that it regains its true value or is the sword destroyed?
The cost of polishing is, of course, in proportion to the value of the sword.

 

Want more clear pictures of these swords in comparison with ordinary polished swords.

 

// Robert

[AntiquarianCat]

There are several bad acid polish examples in NMB’s archives. The worst off ones make it hard to see the habuchi and turn the hada into some garish “Damascus hada” like pattern. I honestly still have trouble telling some Japanese made victims of FeCl₃ from replicas.

IDK why a vendor would do that to an antique. And I also wonder if part of the reason some of the replicas made in China and other parts of the world look as odd as they do is because an acid bath is included in their manufacture.
Brian and other experienced collectors say that acid etching can be repairable sometimes https://www.militaria.co.za/nmb/topic/17957-my-new-nihonto-with-pics/

[Dave R]

10 hours ago, AntiquarianCat said:

 

IDK why a vendor would do that to an antique.

 

 It's a quick and dirty fix to make the blade more attractive to the uninitiated. Very few if any fairs have good enough lighting to properly judge a blade and an acid wash brings up the detail making the blade more saleable. It's also cheaper than having a proper polish.... You would (or would not) be surprised at how many blades on a dealers table have had this done. 

[Brian]

Looks a lot like this: https://www.militaria.co.za/nmb/topic/33978-what-have-i-got/

 

[Caracal]

 

I have read that some retailers polish their blades with the help of polishing cream to get more effect at a sale. The question is how much it damages the blade and destroys for future treatment with Choji Oil and Uchiko Ball.

 

I have also read that some Japanese retailers recommend good weapon oil instead of Choji oil, what do you say about that?

 

 

//Robert

[16k]

Polishing cream is bad for a real Japanese sword. First, the cream is going to get into the folds of the metall, hiding the Hada, then, the polish will remove or partially erase both the nugui and hazuya make up. So bad, bad, bad!

 

As for oil, I use Choji, but the current recommendation is Tsubaki oil or machine oil.  and Uchiko is only recommended on swords which aren’t in great polish. Today, most people use isopropyl alcohol to remove old oil.

 

[Caracal]

So then you recommend that if you think it is polished with polishing cream first clean with isopropyl alcohol to remove the old polishing cream.
Then oil with Tsubaki oil or machine oil, not Weapon oil?

 

What is the negative effect on the sword with Choji oil because you recommend it to old polish?
 

//Robert

[16k]

It’s not choji oil that is dangerous, but uchiko. Quality uchiko shouldn’t be an issue, but uchiko is basically grinding stone residue and can scratch a blade in new polish. On the contrary, a blade in bad state will benefit from uchiko. 
 

According to Aoi, Choji oil is sticky and vegetable oil and more sticky, so more prone to create rust than mineral oil.

[Dave R]

 Define "weapon oil", if you mean gun oil then for the most part they contain solvents to remove propellant residue  and fouling from the projectile..... not the best oil for nihonto.

 I know some people use sewing machine oil, and "Choji" is in fact Tsubaki oil with a little Clove oil added, one story being that the clove was added to stop Mrs Samurai from cooking with it, and another story is it discouraged insects from eating the saya, and also reduced stickiness.

 In the Aoi-art video he uses Kurobara oil which is a commercial brand, and a mix of oils it is also the choice of Japanese Chef's and Carpenters for their blades. From what I can gather, Kurobara brand is mainly tsubaki with enough high grade mineral oil to reduce stickiness and a touch of perfume added.

 For what it's worth, it is my favoured oil for my collection.