# So... how to fix the scratches after thinning a damacus/ suminagashi knife?



## marginCall (Apr 11, 2019)

So, I have sharpen and thinning 3 damacus knives, a shun classic, hattori gyuto and takayuki santoku. These are all my non knife friend's blades.

They perform way better but they dont seem as excited about it because the pattern is scratch. 

I am thinking wet sanding to 1k to 2k grit then etch it with vingear? is this a good plan? what is the proper etchent for stainless and carbon steels? 

Thanks.


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## inferno (Apr 11, 2019)

ferric chloride, maybe. Vinegar probably wont do anything to stainless damascus.


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## JBroida (Apr 11, 2019)

ferric chloride is what i use... i feel like i need some H2O:HCl too for texture.


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## CoteRotie (Apr 11, 2019)

I use C2H6O, but I don't have any conventional damascus knives so I just ingest it directly.

I do have a Saji rainbow, but I wouldn't try ferric chloride on that because it would likely destroy the copper (Maybe a very short exposure?). I recently dropped it by accident into a stainless steel sink, and chipped the blade and tip. After thinning and repairing the chip and tip, I just polished on a succession of stones and finished up with Simichrome. It looks OK now, needs a little more work but if anyone has any ideas about bringing out more contrast in the layers without eating away at the copper/brass let me know. Sorry for the bad iPhone photo.


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## PappaG (Apr 11, 2019)

Back in the day (about 2 years ago!), when I still had my shuns, I did a lot of research on this forum about getting rid of the scratches on Shuns. The conclusion I took from my research was that the shun classic does not respond so well to ferric acid and its basically a faux damascus finish...In other words don't bother. Not saying I'm right about this, but this is what I learned when I was researching how to pretty up the shuns.


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## Michi (Apr 11, 2019)

PappaG said:


> the shun classic does not respond so well to ferric acid and its basically a faux damascus finish.


Hmmm… From the Shun website:

“Steel: Proprietary VG-MAX cutting core, 34 layers each side (68 total) stainless Damascus cladding”

Are you suggesting that this is a lie? I’d be very surprised if this actually were the case.


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## PappaG (Apr 11, 2019)

Just relaying what I read. I would enjoy seeing a before and after of a shun classic that had scratches before and after some scratch removal and acid treatment


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## Michi (Apr 11, 2019)

PappaG said:


> Just relaying what I read.


I think it is _extremely_ unlikely that a reputable company such as Shun would claim that the knife is clad with layered steel when it is not.

If the Damascus pattern fades after scratch removal, that does not necessarily mean that the pattern is fake, but that it was etched initially to increase contrast. In that case, re-etching should bring the pattern back.


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## JBroida (Apr 11, 2019)

It is indeed clad and etches just fine... sandblasting gives a closer to new look though


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## PappaG (Apr 12, 2019)

OP - this may be helpful: https://www.kitchenknifeforums.com/threads/stainless-etching-options-restoring-shun-finish.32709/


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## marginCall (Apr 12, 2019)

Thanks for the suggestions everyone. So do I dip or wipe the blade? And do I need to arrest the reaction? 

Sorry for the questions. But I dont really want to mess up other peoples' knives. 



JBroida said:


> ferric chloride is what i use... i feel like i need some H2O:HCl too for texture.


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## GorillaGrunt (Apr 13, 2019)

Unfortunately I don’t have pictures and have since sold the knife, but I’ve done it to a Shun a couple times. It doesn’t come out looking like they do new because as mentioned above that probably has some blasting and buffing involved, but ferric chloride and fine sandpaper gives a nice proper Damascus look. I’ve also used Works toilet cleaner (10% HCl). Duh, but do it outside, use goggles, gloves, and a respirator...

Dip and wipe methods both work. To stop the reaction I rinsed in water and then covered with baking soda, then rinsed that off.

And if I can get it to look all right not knowing what I’m doing, anyone can!


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