Red iron oxide paste as a Hamon enhancer on Japanese style blades

[Belt Grinder]

Hi, I have a few questions about achieving a frosty or milky white Hamon like on one of those authentic Japanese blades.

Some people use red iron oxide that they mix in a paste with oil. Then they mask the Hamon with nail polish and apply this red iron oxide paste to the remaining body of the blade. This is said to "darken" the Ji portion of the blade and make the Hamon appear lighter in color.
My first question is: does this red oxide paste chemically darken the blade? Or is it just a type of "paint" or a "stain" that you can easily rub off with a cloth?
Wouldn't the red paste make the blade appear red-ish in color?

Also, is there any other (easy) way of making the Hamon appear milky white? (other than painstakingly rubbing it with a hazuya stone, which barely affects modern steels anyway)

We are talking a T10 blade here.
This is what I am after (the one on the left):

 

[Richard338]

The hamon thread has a lot of discussion about different methods and appearances.
Sadly a lot of the images are lost, but enough remain to be worth looking through it.

The Hamon Thread

We have quite a few discussions about hamon here, so I thought it would be good to try to put it all in one place. New or master, if you want to share a technique, or as a question, feel free to do so. I'll start with my basic process, to bring out a nice hamon in a hybrid polish. Its not what...

www.bladeforums.com

 

[Stacy E. Apelt - Bladesmith]

There are many ways to enhance the hamon. One is to use dilute nitric acid on the hamon. You can mask above and below the hamon to etch only the desired parts. This is basically how the faux hamon on some cheap Chinese katana is done.
The use of an oxide powder to enhance the look and color of the ji and ha is common. I have covered much of that in past threads that can be found by using the custom search engine. There is also info in the stickys on this.. A good kit includes rouge (red oxide), chromium oxide (green oxide), magnetite powder (black oxide), cerium oxide (pink oxide), tin oxide ( white rouge), fine alumina powders ( alumina A and B), and various fine silicon carbide abrasives ( valve polishing compounds) are the most common. Choji oil (clove oil) or plain mineral oil is a good carrier. The whole kit can be put together for around $50-100 and will last for many. many swords/knives.
EDM and die polishing sticks can be found in almost any grit and size. These can work like hazuya and jizuya stones. Cratex sticks can be used, too.

 

[Belt Grinder]

There are many ways to enhance the hamon. One is to use dilute nitric acid on the hamon. You can mask above and below the hamon to etch only the desired parts. This is basically how the faux hamon on some cheap Chinese katana is done.
The use of an oxide powder to enhance the look and color of the ji and ha is common. I have covered much of that in past threads that can be found by using the custom search engine. There is also info in the stickys on this.. A good kit includes rouge (red oxide), chromium oxide (green oxide), magnetite powder (black oxide), cerium oxide (pink oxide), tin oxide ( white rouge), fine alumina powders ( alumina A and B), and various fine silicon carbide abrasives ( valve polishing compounds) are the most common. Choji oil (clove oil) or plain mineral oil is a good carrier. The whole kit can be put together for around $50-100 and will last for many. many swords/knives.
EDM and die polishing sticks can be found in almost any grit and size. These can work like hazuya and jizuya stones. Cratex sticks can be used, too.

Thank you for some valuable info, Stacy.
So, do all those oxides actually darken the steel chemically? Do they act the same way a gun bluing solution does? Or do they simply create a thin dark film on top of the steel that can be easily wiped off?

 

[Stacy E. Apelt - Bladesmith]

It is hard to pin down. It isn't a chemical reaction like gun blue. While part of it is oxidation, it is more of the luster and color the steel burnishes to under the oxide grains.
Sometimes you have to try different oxides/grits to get what you want. Sometimes you get something different than you wanted, but like it more.

 

[Belt Grinder]

It is hard to pin down. It isn't a chemical reaction like gun blue. While part of it is oxidation, it is more of the luster and color the steel burnishes to under the oxide grains.
Sometimes you have to try different oxides/grits to get what you want. Sometimes you get something different than you wanted, but like it more.

Thank you once again for the valuable advice.
I am thinking: what if I use regular sandpaper instead of die polishing sticks or Cratex sticks?
What would be the difference in finish between sandpaper and a real hazuya/jizuya stone? After all, both remove metal, but there must be a serious reason why people stay away from sandpaper.
I have read that hazuya and jizuya are acidic, so they also etch the blade. Don't know how true that is, though.

 

[Stacy E. Apelt - Bladesmith]

It isn't just "removing metal", it is how they remove the metal and the surface they leave behind. A large part of using hazuya/jizuya stones is the swarf they create makes a paste that does the polishing. The EDM stones can somewhat duplicate this, and Cratex sticks can be used to get a "frost" in some cases. I wish I could tell you that there is a "one method fits all blades" abrasive or technique ... but there isn't. Togi is a slowly learned process and only experience will tell you what works and what doesn't. Each blade will have different characteristics in the ha and ji and nie and noi, and each hamon has its own blend of structures creating the look and pattern. I also wish I tell you that there was a quick and easy method, but that is also not the case. Creating a highly active hamon through shiage togi is a slow and somewhat difficult process.

Most people today settle on doing a "Hybrid Polish" technique. Do a search on that and it may give you what you are looking for.