Repair Scratches on Knife Face

[carlx]

I have a couple of Wusthof Grand Prix knives that saw the wrong end of a diamond steel, and have scratches above the edge along the face of the knife. Some of them are pretty deep and seem to create drag while cutting.

What's the best way to remove these scratches? I have Naniwa stones in 220/1000/6000, but I've read elsewhere that sandpaper is the best method.

What's the best way to repair the scratches?

 

[Threethreethree]

Sandpaper might be mandatory if the gouges are deep, otherwise i just put SIC slurry on a balsa bit and then rub it in swirly motion so it creates a random circular pattern really good at hiding scratches while not being vile to the eye.
Its way less involved than a full sequence of sanding, and it doesnt eat up your edge like a stonewash beadblast or Scotch Brite buffing would.

 

[carlx]

Sandpaper might be mandatory if the gouges are deep, otherwise i just put SIC slurry on a balsa bit and then rub it in swirly motion so it creates a random circular pattern really good at hiding scratches while not being vile to the eye.
Its way less involved than a full sequence of sanding, and it doesnt eat up your edge like a stonewash beadblast or Scotch Brite buffing would.

What is an SIC slurry? What is a balsa bit?

 

[REK Knives]

What is an SIC slurry? What is a balsa bit?

Silicon Carbide... they sell different grits from lapidary stores online. Balsa is a type of wood that people use for strops.

i would suggest hand sanding it if you want it to look nice... start with the lowest grit you need to to get the scratches out and then progress upward.

 

[Jason B.]

Diamonds dig deep, you might find it a waste of time without a belt sander.

 

[carlx]

Diamonds dig deep, you might find it a waste of time without a belt sander.

They're not so bad, but you can definitely see them.

If using sandpaper, should I dry sand or wet sand? What grit would you start with?

 

[REK Knives]

They're not so bad, but you can definitely see them.

If using sandpaper, should I dry sand or wet sand? What grit would you start with?

Get good quality 3m paper made for metal (auto body shop if possible). use the wet/dry stuff and use it with some wd40 or some type of oil for best results.

 

[Obsessed with Edges]

They're not so bad, but you can definitely see them.

If using sandpaper, should I dry sand or wet sand? What grit would you start with?

I have a Wusthof tomato knife with similar scratches on it. Assuming yours is a full flat grind, a decent satin finish could be applied using ~320-400 grit wet/dry sandpaper on a hard backing (glass or smooth & flat stone works great). Lay the blade flush to the paper and push in an edge-trailing direction, to make grind lines perpendicular to the spine. You could also do this in a tip-trailing direction, to leave the grind pattern running lengthwise. Using the paper WET would likely be cleaner, for the sake of the finish on the blade. I recommend sticking the paper to the hard backing, to make sure it stays fully flat and doesn't move; the grind pattern left will be messy, if the paper moves under the blade while sanding. I also recommend pushing only in one linear direction, if you'd like to keep the sanding pattern as uniform as possible (no back/forth scrubbing).


David

 

[Jason B.]

David gives some good advice, only thing I would like to add,

Once finished with the sandpaper use fine scotch brite with the same method. Just a few passes on each side of the blade will "soften" the grind pattern and add a little shine to the blade. Seems to help with blade friction too.