11-09-2017, 12:45 PM
Whenever I see numbers 230-270 I suspect that not all the burr is removed. Get a good loupe or better yet a USB microscope and see if what you are doing is leaving burr. Maybe that’s what’s going on. Just a guess. I'm not saying that 250 or so is not a perfectly good level of sharpness. In fact it may have better edge retention in the long run than a 150 edge. We still need to do some edge retention tests to see how that pans out.
I don’t do anything very fancy at all. I use a Kally with a home made knife rest to maintain a constant sharpening angle, a 150 grit belt (I like the Cubitron belts) for sharpening, and the rough side of a Surgi-Sharp leather belt for deburring. The Kally sharpens edge trailing when sharpening.
Unless there is a lot of steel to be removed, I use a very light touch when sharpening. Light enough so there is basically no visible belt deflection. As soon as there is any burr, flip the blade over and do the other side. I do that just to keep the amount of burr to a minimum. Once the edge is evenly ground it’s easy to get a nice, even little burr along the entire edge. Then flip the blade and form the little, even burr on the other side. Then I do one or two quick extremely light passes, barely touching the blade to the belt, on each to lessen the burr.
A note on the burr: Once the blade is sharp, forming a burr takes only one, light pass. If you can feel the burr, that's all that is needed. Sometimes the burr can be difficult to see, but easy to feel. There is no reason to make a big, gnarly burr. It's not needed and is more difficult to remove. Create as little burr as possible.
For deburring, I do a light pass on each side at sharpening angle, and quick, very, very light passes at about 45° to the edge to bend the burr back and forth.
I put a little compound on the belt months ago and have not added any since. I wish I had just used a little oil instead, just to make the belt a bit less dusty as a perfectly dry belt tends to be a bit dusty when using the rough side.
I don’t use compound because I don’t want to grind away the toothy edge. I don’t want a polished edge, and I don’t care at all about a shiny bevel. Burr removal for me is just friction, and bending the burr back and forth until it breaks off.
I just sharpened a knife last night. 130 in the middle of the blade, but 265 on the rounded part near the tip. I checked with a loupe, and sure enough, there was burr in the 265 area. I did a couple of quick, moderate pressure passes on the leather belt in that area and the reading was 165. Good enough for that knife.
With a really dull blade it’s OK to use more pressure just to get the edge basically sharp. The problem with heavy pressure is that it forms a substantial burr that is difficult and time consuming to remove. If I have to do that, the normal, very light pressure sharpening thing removes most of it during sharpening.
Wow. Writing this down appears WAY more complicated than it is!
Basically I just do very light pressure sharpening with a 150 grit belt and deburr gently on the leather belt. This seems to reliably product nice toothy edges 150 or less.
I hope that is not disappointing. There is no real “trick”, and nothing special at all other than I use a very light touch for both sharpening and deburring, and don’t use compound on the belt. It’s very simple and not complicated. Basically, grind the edge at 150 grit, remove the burr.
I think there is a tendency to way over-think this this stuff. If what you are looking for is a highly polished edge with a mirror bevel then a grit progression during sharpening and compounds for polishing is required. But for a nice, sharp toothy edge there is really nothing to it.
Hope that helps. I’m more than happy to answer any questions if you have some.
I don’t do anything very fancy at all. I use a Kally with a home made knife rest to maintain a constant sharpening angle, a 150 grit belt (I like the Cubitron belts) for sharpening, and the rough side of a Surgi-Sharp leather belt for deburring. The Kally sharpens edge trailing when sharpening.
Unless there is a lot of steel to be removed, I use a very light touch when sharpening. Light enough so there is basically no visible belt deflection. As soon as there is any burr, flip the blade over and do the other side. I do that just to keep the amount of burr to a minimum. Once the edge is evenly ground it’s easy to get a nice, even little burr along the entire edge. Then flip the blade and form the little, even burr on the other side. Then I do one or two quick extremely light passes, barely touching the blade to the belt, on each to lessen the burr.
A note on the burr: Once the blade is sharp, forming a burr takes only one, light pass. If you can feel the burr, that's all that is needed. Sometimes the burr can be difficult to see, but easy to feel. There is no reason to make a big, gnarly burr. It's not needed and is more difficult to remove. Create as little burr as possible.
For deburring, I do a light pass on each side at sharpening angle, and quick, very, very light passes at about 45° to the edge to bend the burr back and forth.
I put a little compound on the belt months ago and have not added any since. I wish I had just used a little oil instead, just to make the belt a bit less dusty as a perfectly dry belt tends to be a bit dusty when using the rough side.
I don’t use compound because I don’t want to grind away the toothy edge. I don’t want a polished edge, and I don’t care at all about a shiny bevel. Burr removal for me is just friction, and bending the burr back and forth until it breaks off.
I just sharpened a knife last night. 130 in the middle of the blade, but 265 on the rounded part near the tip. I checked with a loupe, and sure enough, there was burr in the 265 area. I did a couple of quick, moderate pressure passes on the leather belt in that area and the reading was 165. Good enough for that knife.
With a really dull blade it’s OK to use more pressure just to get the edge basically sharp. The problem with heavy pressure is that it forms a substantial burr that is difficult and time consuming to remove. If I have to do that, the normal, very light pressure sharpening thing removes most of it during sharpening.
Wow. Writing this down appears WAY more complicated than it is!
Basically I just do very light pressure sharpening with a 150 grit belt and deburr gently on the leather belt. This seems to reliably product nice toothy edges 150 or less.
I hope that is not disappointing. There is no real “trick”, and nothing special at all other than I use a very light touch for both sharpening and deburring, and don’t use compound on the belt. It’s very simple and not complicated. Basically, grind the edge at 150 grit, remove the burr.
I think there is a tendency to way over-think this this stuff. If what you are looking for is a highly polished edge with a mirror bevel then a grit progression during sharpening and compounds for polishing is required. But for a nice, sharp toothy edge there is really nothing to it.
Hope that helps. I’m more than happy to answer any questions if you have some.