Discussion in 'Sharpening Station' started by friz, Oct 10, 2019.
Hi. How do I fix these? Done wih 800 grit.
You can’t “fix” them. The only thing you can do is refinish the blade. It’s hard to see what the existing finish on the knife is like from the pictures, but either wet/dry sandpaper (starting at around 800 grit or so, depending on what your 800 grit stone is like) and/or fingerstones would be the usual method in my book. It’s possible (probable?) you won’t be able to recreate the factory finish, but you can make it look good.
Look up polish in the forum with sandpaper and you'll find a wealth of information for your situation.
Thanks, I will look up. The idea of the thread is to show the situation. I will now go ahead and proceed looking for sandpaper and fingers stones detailed threads. Thanks guys.
Wear them with pride.
Just a question, are you a home or professional cook? If professional, I wouldn't worry about the scratches, unless they are causing some kind of issue. I used to worry about them, now I don't. I'm going to thin my knife ever so slightly every time I sharpen (thin as much as I'm taking from the edge, very little). And not worrying about the errant scratch from the bread crumbs I didn't see on the towel I'm wiping my knife with....
I am a chef and home cook. This knife is staying home with me though. Really feel pissed after what I did yesterday so I would like to fix without having to thin it.
You won't have to thin it. Go at it with sandpaper. It'll be the easiest way to fix it.
Out of curiosity, can low grit sandpaper (say 220-400) alter the grind of a knife when you're removing scratches?
Ti do that you really Need to Sand paper a lot lot lot lot lot lot
When I heard using sandpaper on a blade it blew my mind, is like covering scratches with scratches.......
I see. So sanding with 220 grit sandpaper isn't the same as running the knife on a 220 grit coarse stone?
Yep. You can't get rid of scratches. Only replace them with progressively finer scratches.
If you want a mirror or semi mirroe polish, you need to be careful to COMPLETELY remove each set of scratches with the next finer paper in your progression. If you just want to imitate the factory finish, you don't need to be super pedantic about this (but do remove the obvious scratches). I also can't get a good read on the original finish from those photos. If I had to guess, I'd say maybe 1200 would look similar.
Which 800 stone did this? If it's a Naniwa, I'd probably start at p1000 or even p1200 sandpaper, as Naniwas are a bit finer.
If I'm refinishing a blade, I will usually dull it a little by VERY GENTLY breadknifing on my finest (dry) stone. Doing it this way makes it easy to resharpen. This prevents you being unable to complete the refinishing because you are in the emergency room.
I use a hard backing on my sandpaper. Having some sort of handle on the hard backing makes it easier too.
EDIT: Which knife is it? If it's carbon or ironclad, you may find that it will look a lot better once patinaed.
No, it works like a 220 grit stone. At least until it wears out, which doesn't take long.
Keep in mind that you are grinding the whole surface of the blade, not making an edge bevel or even a thinning bevel, so the metal removal is spread over a much largerer surface area, meaning less depth of metal removal. Once you have removed the scratches, you move on to the next grit.
When fixing a neglected knife, I often start at p240 or p180, so I would begin my refinishing at p360 or p240. As long as you move on once all of the coarser sctratches are removed, the additional thinning doesn't seem to be a major issue.
I know right? That is my point too. I wonder whether natural stones could solve this.
Yea, the point is that substantial thinning takes forever even with stones and also you don’t (or at least I don’t) use as much pressure with sandpaper, so any thinning that occurs during the refinish is not very noticeable.
Put it this way: if you’re just refinishing, then your only goal is to clean up previous scratches. OP, the scratches on your blade are very shallow. In each step of the refinishing, you’re just trying to get rid of the previous scratches, so you shouldn’t be thinning a whole lot more than the original shallow scratches.
Kato. Vertical finish.
Thanks for the help everyone, see what I can do this afternoon.
You can come closer to the original finish again only if you‘re perfectly parallel to the original scratch pattern and with a similar grain. This requires high skills.
Or you can polish the whole blade but not sure this little scratches are worth the work.
Why a hard backing? I have more even results with hard rubber or soft wood. Avoids facetting.
Bevel looks anyway to big, i would suggest thin it out to nearly zero up to 3k stones, and after this redo the finish with sandpapers 180 to 600 grit and WD 40, or find someone who can do this with an beltgrinder in a few minutes
Like some have said already don’t worry about it.
Good point. OP, you totally need a belt grinder here. Although really, now that you’ve scratched the blade you should probably just reforge it. If you heat it up enough, you can probably get the scratches out with a hammer. Then just temper, regrind it a bit, and then refinish on stones and sandpaper. There are plenty of resources online to help you with this. Just google “how to make a knife kato”.
As long as you're advocating a full court press here, prolly should do something about the handle as well. Suggest planting a quick growing Pakka tree so that bamboo thing can be replaced with some long lasting virgin wood.
I use a (slightly radiused) soft wood (pine) as my "hard backing". Perhaps I should have chosen my words more carefully.
You still can get some faceting if you really grind with a lot of force.
Maybe I'll give hard rubber a go next time.
I went to a blacksmith near my place and he is willing to refinish the knife completely without changing his native geometry but it will cost me 200AUD+ with an horizontal finish rather than vertical, so I will try progressively with sand paper myself or either leave it this way. I will keep looking at the forum for guides (better illustrated) so IF happens that I make that mistake again I will know how to solve it. Thanks everyone for all the informations you have given me.
Jesus man, a knife is a tool. Tools get damaged through use; a shite tool gets thrown out, a good one, repaired and from there informs your skill.
seriously; you need to decide if your knife is an artwork or a tool. One is mounted on the wall and the other used to cut tomatoes. If you want something perfect looking, leave it on the wall. Otherwise, enjoy allowing it to perform its function.
Sure a knife ist a tool, but it may look good to
I do not like scratches or dents in my car, though they do not hurt performance, the same for me with knives
When I get a scratch like this, I use, BlueMagic, lapping papers, Sabitorus, and sand papers. If a scratch is not deep and the finish is mirrorish, compounds like BlueMagic or very fine lapping papers (1 - 10 microns) can HIDE the scratch.
If the finish is hairlined, I first pick up a Sabitoru Fine and try to rebuild hair lines, then if it's too fine, use Sabitoru Medium. These are easy to use and good to have. You can also use Scotch Brite pads. Watch maintenance guys have a lot of tequniques to refinish hairlines so you can steal ideas from them by the way.
If you are not sure which grid of sandpapers fits your finish, start from a finer grid.
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