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View Full Version : how do you turn a mirror-polish into a satin finish?



EdipisReks
10-24-2011, 09:53 PM
i put a mirror polish on my Shigefusa (not scratchless, but it's bright and reflects beautifully), but i'm kinda sick of the tendency to pick up small scratches. i tried using a fairly coarse wet/dry, tonight, and i actually managed to make the polish brighter! any suggestions?

heirkb
10-24-2011, 10:30 PM
Get a rust eraser. I think I have this same one and it has worked well for me: http://korin.com/Rust-Eraser-Sabitoru
I bought mine from Jon, but I don't think it's listed on his site. You should ask him about it.

EdipisReks
10-24-2011, 10:50 PM
i actually own one, i've just never used it on a finish like this before. i'll give it a shot, thanks! i'm guessing moving the knife against the eraser is the way to go, just like finishing with sandpaper...

EdipisReks
10-24-2011, 10:56 PM
hmmm, well, it's a start. the rust eraser doesn't remove much metal, so this'll take a long while. well, better to take off too little material than too much, and it's easy to get even lines.

heirkb
10-24-2011, 11:06 PM
I think you could move the rust eraser if that's easier for you. I laid the knife down on a soft surface with the handle hanging off (so the blade is flat on the surface) and went at it with the rust eraser and a good bit of pressure until the scratches I didn't want were gone. The eraser itself doesn't leave very deep scratches so it wasn't hard to even things out after that. I just ran the eraser in straight lines over the knife a bunch of times with decreasing pressure until I got the best finish I could. I still couldn't get perfectly straight lines because it gets a little tricky around the handle, but it's pretty good.

Edit: I forgot to add that if you have fingerstones or just some kind of slurry off of any stone (except something super coarse), that may help speed up the process.

Eamon Burke
10-24-2011, 11:07 PM
Wait, don't you have fingerstones? Herrroooo

EdipisReks
10-24-2011, 11:07 PM
i put the eraser on one of my DMT no slip pads, positioned the ferrule against the edge of the eraser and then pulled the knife. it's the same way i use sandpaper.

Seb
10-24-2011, 11:08 PM
Chocera #400 or Suehiro Rika for finer. ;)

Be interesting to see what a muddied-up King #800 would do.

Eamon Burke
10-24-2011, 11:11 PM
Chocera #400 or Suehiro Rika for finer. ;)

Be interesting to see what a muddied-up King #800 would do.

you....you're kidding, right?

wsfarrell
10-24-2011, 11:29 PM
I've polished a couple of Shigefusas to a really nice satin finish using 220 wet/dry sandpaper. Put the knife in a knife vise if you have one, put the sandpaper on a sanding block backed by hard rubber (buy one if you don't have one). Lubricate with water with a couple of drops of Dawn added. Polish in one direction only (heel to tip is recommended). Very important: change sanding sheets every time you turn the knife over to work on the other side of the blade. Strive to move the sanding block in a straight line.

I've tried going to 300 and 400 grit, but this starts to give a polished finish, so I always drop back to 220.

Here's a picture of one I just finished:

http://www.downtotheday.com/photos/shige.jpg

P.S. I polished the hagane on a Woodcraft buffer, but that's a whole 'nother story.

heirkb
10-24-2011, 11:29 PM
Wouldn't you have to flatten a good portion of the knife in order for stones to work? If not flatten in the sense of flat grind, you'd at least have to flatten out most of the inconsistencies in the jigane to even do a convex polish on stones, no? At least that's been my experience when I tried to polish the sides of a knife just using a stone (or even a fingerstone that was a little too big).

EdipisReks
10-24-2011, 11:48 PM
Wait, don't you have fingerstones? Herrroooo

i find they work great on the blade road of a single bevel, but i have trouble getting an even finish on double bevel knives, and the finish i get is not really the kind of satin i want.

Eamon Burke
10-24-2011, 11:48 PM
http://www.downtotheday.com/photos/shige.jpg


That's really pretty. Good job!





i find they work great on the blade road of a single bevel, but i have trouble getting an even finish on double bevel knives, and the finish i get is not really the kind of satin i want.

Oh I see. I agree. I see what you mean now.

I find that sandpaper + lubricant is a winning combo. If you use careful, consistent, unidirectional strokes, you can get a phenomenal finish.

I had an obsession for a little while, and wouldn't stop screwing with my Tojiro until it looked like the satin handle on my Gray Kunz Spoon. I believe it was either 220 or 400grit wet/dry sandpaper and mineral oil.

EdipisReks
10-24-2011, 11:58 PM
Wouldn't you have to flatten a good portion of the knife in order for stones to work? If not flatten in the sense of flat grind, you'd at least have to flatten out most of the inconsistencies in the jigane to even do a convex polish on stones, no? At least that's been my experience when I tried to polish the sides of a knife just using a stone (or even a fingerstone that was a little too big).

i've given both faces of this knife a bit of convexing over time, and i rather do think one would have to flatten the sides to work with a stone. anyway, this is what i've ended up with. the light is bad, and it's hard to capture what it looks like. i think it looks good enough that i won't bother to do anything more to it unless i have to. i'd love to end up with wsfarrel's results, though!

http://img15.imageshack.us/img15/9800/shiga.jpg

it's still a bit reflective, but i think it'll be much easier to maintain. the original mirror was done with micro-mesh pads and hand soap foam.

http://img708.imageshack.us/img708/5584/shig2.jpg

EdipisReks
10-25-2011, 12:34 AM
I've polished a couple of Shigefusas to a really nice satin finish using 220 wet/dry sandpaper. Put the knife in a knife vise if you have one, put the sandpaper on a sanding block backed by hard rubber (buy one if you don't have one). Lubricate with water with a couple of drops of Dawn added. Polish in one direction only (heel to tip is recommended). Very important: change sanding sheets every time you turn the knife over to work on the other side of the blade. Strive to move the sanding block in a straight line.

I've tried going to 300 and 400 grit, but this starts to give a polished finish, so I always drop back to 220.

Here's a picture of one I just finished:

http://www.downtotheday.com/photos/shige.jpg

P.S. I polished the hagane on a Woodcraft buffer, but that's a whole 'nother story.

just out of curiosity, how long did it take you to get that satin finish?

wsfarrell
10-25-2011, 01:07 AM
just out of curiosity, how long did it take you to get that satin finish?

Your knife looks good to me.

I hate to admit it, but it only took 10 minutes to do put that finish on mine. Knife in vise, sandpaper on block, 50 strokes on one side, change sandpaper and flip knife over, 50 strokes on the other side, done. Before I had the knife vise I was using all sorts of bizarre setups with c clamps and such, and that was a royal pain. Really helps if you have the right tools.

EdipisReks
10-25-2011, 01:29 AM
hah! i guess the first thing i need to get is some coarser paper. the coarsest i have is 500. i really like my method of moving the knife, as i can get a very consistent draw, heel to tip

wsfarrell
10-25-2011, 02:27 AM
I saw a knifemaker use that technique of moving the knife rather than the sandpaper. Looked pretty slick. Many paths to the same destination.