What Is Russet Iron?

[Pete Klein]

What is russet iron and how is it made?  I cannot find a definition on-line.  All I get if I  Google it is an oxide product or a suit of armor.

 

Thanks much.

[christianmalterre]

"russet iron" is a expression for irons with a higher percentuage of Pentlandite - sulfides.

 

least, this is what it is called.....

 

to ben found in ironsand.....

 

Christian

[John A Stuart]

Strange. I have always thought russet iron is the process by which rusting is used to form a protective oxide layer on barrels, armour etc. Old rifles used this process often, before chemical bluing became popular. Pentlandite, that iron-nickel oxide mineral in iron sand? Odd, iron sand was noted for its' relative purity of iron. John

[Baka Gaijin]

Good morning Chaps.,

 

Sometimes what looks like Russet Iron on Katchu is actually a Lacquered finish.

 

I think it is called Tetsu Sabi Ji Urushi Nuri.

 

This link may be of assistance:

 

https://issuu.com/davethatcher/docs/how_do_they_write_those_description

[DaveT]

Hi Peter, keep it simple.

 

During the sengoku age iron was a scarce commodity. Armour makers were under presure to keep up with demand so the recycled suits and patched suits together. This was all concealed by the lacqured surface.

 

Because you never knew what was under the lacqure russet suits became desirable for the wealthy to demonstrate that the plates were not cobbled together. This became rather fashionable during edo onwards when raw materials were plentiful.

 

The russet finish is still very desirable by collects today. There were many processes to rust the surface, but its controlled rust.

[uwe]

The result of this artificial rusting process is called “tetsu sabiji”. A passive surface structure, that protects the iron permanently!

That’s all I can add. For more information we need an restorer to jump in!

Oh, just noticed that Dave already...

[IanB]

 What is not well known is that the russet finish on armour was originally oiled to prevent secondary rusting. With age old russet pieces become covered in secondary rust when the old oil has evaporated or failed. Some fifty years ago I acquired an armour that was almost completely russet and was beginning to show spots of secondary rusting on many of the plates. Being totally ignorant I decided to treat the surface in the same way that the finest gun-makers treated their barrels and apply a drying oil. The process I eventually settled on was to remove the secondary rust with a chisel shaped bone scraper, softening the hard secondary rust with a 50 / 50 mixture of boiled linseed oil and white spirit. Afterwards wiping off the excess oil with absorbent paper until no more came off. The oil that soaked into the russet layer oxidised in a week or so, was touch dry and had formed a more or less permanent seal. That armour still looks exactly as it did 50 years ago with no more secondary rusting and a rich chestnut coloured surface that still retains a beautiful soft sheen. 

Ian Bottomley

[DaveT]

Are we going to talk about the urine process?

Ian kinda summed it up with regard to secondary rusting. 

[SAS]

Sssshhhhhhh.....no shishi tales.....top secret ya know...

[Pete Klein]

OK - then Russet Iron is actually iron which has been treated by an oxidation process to seal the surface which helps to prevent future rusting and may have subsequent sealing done via oil or other methods?

[Henry Wilson]

I would not say that russet iron is necessarily treated.  I would identify the russet effect as variations of a rough, rustic austerity as seen below.

 

Rough and ready

Smooth and slinky

 

Check out tea ceremony kettles, especially Tenmyo and to a lesser extent Ashiya, for (what I would call) classic examples of russet iron.  An interesting write up is at the link.

 

http://www.mtlo.co.jp/us/valueone/metal/sano/sano.html

[b.hennick]

Thanks for the link Henry! It was an interesting read. 

[Pete Klein]

Tea kettles / tetsubin are cast iron.  I believe armor is forged plates.  Tetsubin are often finished with urushi on heated metal externally as a sealant. 

[Jean]

Mine

[DaveT]

Correct, they never made katchu from cast iron. However, the teapots are nice.

Here is one on my hachi in russet, you can see where there is secondary rusting.

The above hachi before its oil treatment.


Again, secondary rusting ( in a museum!!!! )


Here is some mild steel that been coated with burnt on urushi which acts as a primer and ruststopper.

[Henry Wilson]

Tea kettles / tetsubin are cast iron.

 

Correct, they never made katchu from cast iron.

 

Yes, that seems to be the conventional wisdom. My point is, regardless of whether cast iron or forged, russet appears to be the same thing, which is a patinated worn surface effect.  How it is obtained seems to be a means to an end.