Hamon polishing...

[velferd]

I started this blade a while ago, but things kind of got in the way of finishing it, so it sat on my etching shelf for far too long. Well I decided to carry on polishing it today. Here is it so far:
20161226_162222[1] by velferd, on Flickr
20161226_162127[1] by velferd, on Flickr

This was my first attempt at a clayless hamon, and I am rather happy with the results. Plenty of activity, but the surface finish seems a bit dull to me. It reminde me of the dull side of tin foil, and I am seeking a brighter finish like I have gotten in the past. I usually do this by taking one or two passes with 2000 grit sandpaper and then using powdered abrasives to bring out the hamon, but this just removes too many subtle features of the hamon. The blade has currently been vinegar etched countless times and scrubbed with silicon carbide powder (500 mesh I think, but I really don't know, it came from a lapidary kit and is labeled pre-polish) to uncover the hamon, but it has left the dull/matt finish I cant seem to get rid of.

I think I am going to try using different carriers for the SiC next, as I currently use a water, soap, and baking soda mix like I do when wet sanding. IIRC I have tried both wd40 and oil with no results, but don't exactly remember, since I took some time off this knife. I did try dissolving red and white buffing compound and using a rag to spread them around (separately), but it basically washed out the hamon.

Any suggestions? I've probably got less than 10 knives under my belt so far, so any comments and critiques are more than welcome.

 

[kuraki]

I'm certainly no expert, and I'm going for a particular look, I want to see 3 colors, near black, dark grey, and white or cloudy bare metal. I've figured out how to get that relatively quickly and easily. I use 1:6 ferric chloride. Basically take to 1200 grit, then etch for 15 or 20 seconds, polish very lightly with blue magic, this was trial and error. It's very easy to polish all the oxides away. So I dab a little on, wipe it off, then polish with a clean paper towel until the residue is all picked up.

Then rinse repeat. 3 to 4 rounds of this and the colors develop into what I'm looking for.

I can't really take pictures with my cell phone that do these justice.

 

[kuraki]

Forgot, this is the compound I'm using. It's basically simichrome from what I can tell, the carrier paste is just thinner and easier to wipe away.

 

[Stacy E. Apelt - Bladesmith]

I have a kit of polishes and etchants. I have Maas metal polished, Flitz, Simmichrome, and some others. I have 1200 grit SC, along with a variety of oxide powders - tin, cerium, chrome, red and black iron, etc. I use very 15-1 FC, 100-1 nitric acid, vinegar, and lemon juice as etchants. Another good item is the 3M polishing papers that go up to 8000 grit. For working the polishes and powders, I use makeup cleaning pads.

You have to experiment with all these to find which work best on your type of hamon. There is no one does it all answer. Different things will affect the hard martensite edge, the softer pearlite upper blade, and the mixed structure transition zone. Additionally, nie and nioi will act different with different polishes.

Once you select your kit for a blade, you work the areas separately. Polishing the whole blade is like spray painting a whole wall when you are trying to paint a mural. You only want to work the areas that the polish/compound being used is best for. You can tape off or paint with nail polish the areas that you don't want messed up. I like to etch and polish the hamon activity first to get the white wisps, mask them off with nail polish, and then do the edge, and finally the upper part.