Cleaning up scratches/blemishes?

M

Mettius

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Dec 30, 2015
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For about two years I used this... (image below)
2016-01-01 15.24.01 by Erich Weidner, on Flickr
...a few times/year to sharpen my kitchen knives. I never really felt like I got the hang of where to hold the blade... but I digress. I recently ditched it for hand sharpening on water stones, which has given me better results. But the old wheel thingie scratched and scuffed up the sides of the knives pretty good.

What method/materials should I use to polish the knives back to being a bit pretty again?

Here is what it looks like now.
2016-01-01 15.23.19 by Erich Weidner, on Flickr
 
Well let me say this about that . . . you are out of luck.

Well . . . unless you are up for using quite a bit of elbow grease and time.

First off what I am showing in my photos. When I retired my rag tag pile of water stones and went with all new Shapton Pro stones I already had a plan for the old stones. I scored the end of the stone all the way around using a carbide rod saw (inexpensive thing they sell at most hardware stores that you can put on your hacksaw to hacksaw hard stuff with). Then broke off little rectangles of the stones. I use these to sharpen small pocket knives but also I use the end of the stone to polish blades with. Ignore the Spyderco knife in the photo; I didn't use the stones on the sides of the knife; I just happened to have these photos of my stones and the knife was in one of them.

But
you are going to have to abrade the entire surface of your knife with the same grit (be it abrasive coated cloth or a stone like mine) to make the side of your knife look right. All the scratches should probably be parallel to the factory scratch pattern that we can see in your photo until they remove the scratches the plastic sharpener thing put on your knife. Alternatively you could, I suppose send the knife off to a knife maker and have them refinish the knife. Not what you wanted to hear was it ? Sorry dude.

PS : assuming you are going to use cloth (or paper) backed abrasive two to look at are :

1. Blue Norton zirconia coated cloth. Don't confuse this with Norton's Blue-Bak which is NOT zirconia but is more like the next one I am going to mention see #2.
The zirconia cuts hard steel fast and will be the fastest way to get the whole surface to one scratch pattern.

2. Basic old Silicon Carbide wet or dry. This stuff will give you a smoother look and can achieve a near mirror polish if you get crazy with it but it will take for EVER to get the scratches off your knife. Use the zirconia stuff first and you may want to just stop there and not even go with #2



 
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Progressively finer stones followed by pressing progressively finer stroping compounds. Ya gotta get rid of all of those scratches and make the bevel truly flat. The flatter it is, the more reflective it is.
 
jamiesaun said:
If you're talking about the primary grind, you can clean that up with sandpaper.
Click to expand...

And relatively easily too. The steel in that blade isn't very wear-resistant and shouldn't be too difficult to refinish with some wet/dry sandpaper (silicon carbide and sometimes aluminum oxide).

Lay a sheet of 220/320-grit wet dry sandpaper over a hard surface like glass/stone. Preferably, you'd also want to make sure it's held tight, flat & flush in place; tape the edges, or use a little temporary adhesive on the back of the paper.

Move the knife in an edge-trailing (spine-to-edge) direction over the sandpaper, parallel to the original grind lines on the blade. Move only in one direction; back & forth will distort the scratch pattern (lines won't stay straight), and it won't look as good. With a larger blade like yours, placing one/two sheets of plain paper under the sandpaper can give it just enough 'cushion' to more evenly sand the larger area of the blade (this avoids uneven sanding patterns that might result with slight undulations in the grind of the blade). Try to keep your hands/fingers over portions needing the work, to regulate pressure.

You could also just lay the blade flat, and use a block of wood with sandpaper wrapped around it, and sand the affected portion that way. A lot depends on how bad you want to make the WHOLE blade look evenly-finished (sand as above), or if you're willing to accept just tidying up the scratched portion itself (a small sanding block can do that). Either way, it's not the end of the world if it doesn't look perfect the first time; you can still re-sand it later on, if/when you feel more comfortable with the method.


David
 
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Obsessed with Edges said:
And relatively easily too. The steel in that blade isn't very wear-resistant and shouldn't be too difficult to refinish with some wet/dry sandpaper (silicon carbide and sometimes aluminum oxide).

Lay a sheet of 220/320-grit wet dry sandpaper over a hard surface like glass/stone. Preferably, you'd also want to make sure it's held tight, flat & flush in place; tape the edges, or use a little temporary adhesive on the back of the paper.

Move the knife in an edge-trailing (spine-to-edge) direction over the sandpaper, parallel to the original grind lines on the blade. Move only in one direction; back & forth will distort the scratch pattern (lines won't stay straight), and it won't look as good. With a larger blade like yours, placing one/two sheets of plain paper under the sandpaper can give it just enough 'cushion' to more evenly sand the larger area of the blade (this avoids uneven sanding patterns that might result with slight undulations in the grind of the blade). Try to keep your hands/fingers over portions needing the work, to regulate pressure.

You could also just lay the blade flat, and use a block of wood with sandpaper wrapped around it, and sand the affected portion that way. A lot depends on how bad you want to make the WHOLE blade look evenly-finished (sand as above), or if you're willing to accept just tidying up the scratched portion itself (a small sanding block can do that). Either way, it's not the end of the world if it doesn't look perfect the first time; you can still re-sand it later on, if/when you feel more comfortable with the method.


David
Click to expand...

Good advice on the one direction only. Took me a lot of time to figure this out. It takes a lot longer, but it's worth it if you want it perfect. Stay away from powered devices or polishers until you really have a ton of skill. They take a real pro to do it right.
 
The dinged up spine on the utility knife could be cleaned up by grinding/sanding it flat again. I've done this with a couple of mine, using either a sharpening stone, like a silicon carbide stone, or some wet/dry sandpaper laid flat on a HARD surface, like stone/glass/hardwood. The method is very easy; just lay the spine flush to the hard-backed abrasive, and drag the spine heel-to-tip across it (keep the spine at as low an angle as possible, to protect the tip of the blade, in finishing the stroke). Something like 150-220 grit would likely get it flat & clean pretty fast. After it's flat & flush again, some 320-grit would get it looking closer to factory finish again. This method is also good for making tips pointy again, if they're blunted or rounded over.

BTW, I've used a wine cork pressed onto the edge of the blade as a place to exert pressure with a finger/thumb, while grinding the spine of the blade. That allows use of some extra pressure and you can position the cork (or piece of wood, etc) to exert pressure directly over specific areas being worked. Adds some extra control.


David
 
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