DKsharpshooter
BANNED
- Joined
- Apr 9, 2008
- Messages
- 5
Edge polishing is typically done for one of two reasons, for aesthetics or specialized types of cutting. If you are doing it for aesthetics, nothing more need be said; however, if you are considering polishing as a means of obtaining a better cutting edge on your blade, then you will first need to consider how you plan to use it.
Polishing your knife's edge is something that can be done to any desired degree. If you are really hardcore and want to be able to press-cut through a baseball bat, then polishing the edge to a finish similar to that found on a brand new light bulb is your goal. On the other hand, if you just want to provide a little more sharpness and durability, while maintaining a good slice-cutting edge, then just a little polishing to remove the burr, improve the shape of the bevel, and reduce resistance may be all that's needed. Then, of course, there's everything in between.
When a knife is sharpened using any kind of hard abrasive, such as a stone, tiny scratches are created on the edge bevel. As you progress through ever finer grit stones, each successive stone polishes out the deeper scratches left by the previous, coarser stone, while leaving shallower scratches of their own. At some point, depending upon what type of stones you are using, you will have polished your bevel as much as possible with your finest grit stone; however, this is nowhere near the level of polishing that is possible. Some kinds of stones have the ability to go to much higher polishing levels than others. For more information about this, see my post titled: Sharpening Stone Grits and How They Compare.
Anyway, once you've finished with your finest stone, this is where stropping comes in. By using a progression of leather strops, each with a finer grit diamond paste applied to the surface, you can literally polish the bevel to a glass-like finish on a microscopic scale. At this point, all of the microserrations created by the last stone will be completely erased along with those created by the coarser grit strops.
At any point in the stropping process, you can stop stropping at the desired level of polish. This leaves you with an edge that is tailored to your particular cutting needs. So now for a little bit about your particular cutting needs. Let's start with tomatoes!
It is actually possible, and in fact, not too difficult with the right equipment, to polish an edge to the point where it literally will not cut through the skin of a tomato. This is because a tomato is soft and squishy inside, but the peel is, albeit thin, quite tough. When you try to slice through the peel with a finely polished edge, the squishy inside gives way under pressure. There's little resistance to pressing and no tearing or ripping of the peel can occur since all the microserrations are gone. So for a tomato, only a little polishing is recommended. I do recommend some small amount of polishing because using a strop to finish off the burr created while using the stones, as well as creating a slight convex bevel, will result in a much more durable edge. Regular stropping with the coarser grits will keep your edge shaving sharp and over time will produce a bevel with the ultimately durable gothic arch shape.
Want to cut leather? You might want to do a lot more polishing. Want to cut meat? Less polishing. It all comes down to how much you intend to press-cut vs. slice-cut. If you are planning to do both, then some level of polishing in the middle range is probably what you're after. It may take a little trial and error to figure out what level of polishing works best for your particular needs.
One thing you will notice when stropping, if you look at your bevel under a magnifying lens, is that you can obtain a nice reflective mirror finish without removing all the microserrations. This is because the peaks or ridges of the microserrations get polished, but not completely removed. To completely remove the microserrations created by your finest sharpening stone, you will need to spend extra time with your coarsest grit strop. The coarsest grit strop will still make microserrations of its own, but they will be a lot smaller than the ones left by the stone.
I mentioned removing the burr earlier by stropping, so let's go into this a little bit more because it is really very important. As you progress through your ever finer grit stones, you should be applying less force to the blade during the last few strokes. This aids in reducing the size of the burr. To completely remove the burr, a few light strokes with a strop will do the trick. The key to stropping is setting it at the correct angle. Since the leather is soft and pliable compared to the rigidity of the stones, if you strop at the same angle you sharpened your knife at, the leather will tend to fold over the edge just slightly. Depending upon what kind of bevel you put on your knife (single, double, triple) and how thick the blade is, you may need to reduce the angle by as much as one degree. This allows you to very precisely control removal of the burr without going too far and dulling the edge. To do this, you will need a sharpener that provides a continuously variable angle adjustment. [ moderator edit: an ad that's "hidden" is still an ad ]
Polishing your knife's edge is something that can be done to any desired degree. If you are really hardcore and want to be able to press-cut through a baseball bat, then polishing the edge to a finish similar to that found on a brand new light bulb is your goal. On the other hand, if you just want to provide a little more sharpness and durability, while maintaining a good slice-cutting edge, then just a little polishing to remove the burr, improve the shape of the bevel, and reduce resistance may be all that's needed. Then, of course, there's everything in between.
When a knife is sharpened using any kind of hard abrasive, such as a stone, tiny scratches are created on the edge bevel. As you progress through ever finer grit stones, each successive stone polishes out the deeper scratches left by the previous, coarser stone, while leaving shallower scratches of their own. At some point, depending upon what type of stones you are using, you will have polished your bevel as much as possible with your finest grit stone; however, this is nowhere near the level of polishing that is possible. Some kinds of stones have the ability to go to much higher polishing levels than others. For more information about this, see my post titled: Sharpening Stone Grits and How They Compare.
Anyway, once you've finished with your finest stone, this is where stropping comes in. By using a progression of leather strops, each with a finer grit diamond paste applied to the surface, you can literally polish the bevel to a glass-like finish on a microscopic scale. At this point, all of the microserrations created by the last stone will be completely erased along with those created by the coarser grit strops.
At any point in the stropping process, you can stop stropping at the desired level of polish. This leaves you with an edge that is tailored to your particular cutting needs. So now for a little bit about your particular cutting needs. Let's start with tomatoes!
It is actually possible, and in fact, not too difficult with the right equipment, to polish an edge to the point where it literally will not cut through the skin of a tomato. This is because a tomato is soft and squishy inside, but the peel is, albeit thin, quite tough. When you try to slice through the peel with a finely polished edge, the squishy inside gives way under pressure. There's little resistance to pressing and no tearing or ripping of the peel can occur since all the microserrations are gone. So for a tomato, only a little polishing is recommended. I do recommend some small amount of polishing because using a strop to finish off the burr created while using the stones, as well as creating a slight convex bevel, will result in a much more durable edge. Regular stropping with the coarser grits will keep your edge shaving sharp and over time will produce a bevel with the ultimately durable gothic arch shape.
Want to cut leather? You might want to do a lot more polishing. Want to cut meat? Less polishing. It all comes down to how much you intend to press-cut vs. slice-cut. If you are planning to do both, then some level of polishing in the middle range is probably what you're after. It may take a little trial and error to figure out what level of polishing works best for your particular needs.
One thing you will notice when stropping, if you look at your bevel under a magnifying lens, is that you can obtain a nice reflective mirror finish without removing all the microserrations. This is because the peaks or ridges of the microserrations get polished, but not completely removed. To completely remove the microserrations created by your finest sharpening stone, you will need to spend extra time with your coarsest grit strop. The coarsest grit strop will still make microserrations of its own, but they will be a lot smaller than the ones left by the stone.
I mentioned removing the burr earlier by stropping, so let's go into this a little bit more because it is really very important. As you progress through your ever finer grit stones, you should be applying less force to the blade during the last few strokes. This aids in reducing the size of the burr. To completely remove the burr, a few light strokes with a strop will do the trick. The key to stropping is setting it at the correct angle. Since the leather is soft and pliable compared to the rigidity of the stones, if you strop at the same angle you sharpened your knife at, the leather will tend to fold over the edge just slightly. Depending upon what kind of bevel you put on your knife (single, double, triple) and how thick the blade is, you may need to reduce the angle by as much as one degree. This allows you to very precisely control removal of the burr without going too far and dulling the edge. To do this, you will need a sharpener that provides a continuously variable angle adjustment. [ moderator edit: an ad that's "hidden" is still an ad ]
