Sharpening angles with a reference surface
Posted: Mon Aug 14, 2023 9:07 pm
My first success with knife sharpening and holding an angle was using what I always called cross sticks. Examples include the Spyderco Sharmaker (15° or 20°), AG Russel ceramic sharpening rod (15°), Lansky 4-Rod turn box (20° or 25°), and Dan’s Whetstone Arkansas Sticks to name a few. The Work Sharp Angle Set Knife Sharpener has an even wider range of angles that work off this principle.
It is easy (ish) to hold a knife vertical and pull the knife across the sharpening medium. I love this method to refine an edge and to keep it sharp. Here, your reference point is holding the knife vertical.
If you are good enough to simply free hand sharpen, you can avoid the problem, but when I free hand sharpen, I use angle guides against a reference surface, which is why I was thinking about this problem.
There are other systems that make good use of the trigonometry that hold the knife at precise angles. The most revered (and most expensive) is probably the Wicked Edge Precision sharpener. Less expensive options include Work Sharp Professional Precision Adjust Knife Sharpener as well as the Lansky sharpening system. I really do want a Wicked Edge Precision sharpener but it is not in my budget right now and I own many products already. Someday perhaps.
My first time sharpening a kitchen knife, I laid the knife flat on the stone then placed a coin (or two) between the stone and the spine to set the angle. Not very precise, but I did end up with a very sharp blade. I won’t bother with the trigonometry behind this, but if you really want to see some math, let me know.
If you are looking at holding a consistent angle on a sharpening stone, I am a huge fan of the Wedgek Angle Wedges. You set the guide on the stone, you can even secure it with a rubber band. Next, you place the knife on the wedge to set your angle and you are good to go….. or are you?
Some knives have a full flat section on which to rest the blade when setting the angle, but many do not; for example, look at the blades on this Case Seahorse Whittler.
I did not measure any angles from the factory, but… The factory blade has a long bevel to the spine around 10° with the secondary bevel near 27°; so about 17° between the primary and secondary.
Without thinking, I placed the blade onto a 13° wedge, which created a secondary bevel near 23°. Again, without thinking, I used my Spyderco Sharpmaker to set a 15° angle but it was not getting sharper because I was removing metal far from the edge.
The only available reference surface is already at 10° so I need a reference angle near 3° to get a 13° final angle.
Where else do you need to worry about your reference angle? One of my favorite sharpeners is the Work Sharp sand paper belt sharpeners, I own a couple versions. The Ken Onion version with the Blade Grinding attachment has a flat reference surface. The idea is that you set your blade on the reference surface and then hold that reference to get the angle set on the attachment.
https://www.sharpeningsupplies.com/Work ... 31C68.aspx
This is a potential problem with most systems where you are trying to actually measure your angle. The Wicked Edge Precision sharpener looks like it should not have this problem, especially if you are using an angle measuring guide on the bars, someday I will have one to test perhaps. I also do not see this as a problem with the Tormek system that I use, but I have not tried their machine specific to knife sharpening.
Finally, I did not attempt to discuss how different grinds may affect the reference surface.
It is easy (ish) to hold a knife vertical and pull the knife across the sharpening medium. I love this method to refine an edge and to keep it sharp. Here, your reference point is holding the knife vertical.
If you are good enough to simply free hand sharpen, you can avoid the problem, but when I free hand sharpen, I use angle guides against a reference surface, which is why I was thinking about this problem.
There are other systems that make good use of the trigonometry that hold the knife at precise angles. The most revered (and most expensive) is probably the Wicked Edge Precision sharpener. Less expensive options include Work Sharp Professional Precision Adjust Knife Sharpener as well as the Lansky sharpening system. I really do want a Wicked Edge Precision sharpener but it is not in my budget right now and I own many products already. Someday perhaps.
My first time sharpening a kitchen knife, I laid the knife flat on the stone then placed a coin (or two) between the stone and the spine to set the angle. Not very precise, but I did end up with a very sharp blade. I won’t bother with the trigonometry behind this, but if you really want to see some math, let me know.
If you are looking at holding a consistent angle on a sharpening stone, I am a huge fan of the Wedgek Angle Wedges. You set the guide on the stone, you can even secure it with a rubber band. Next, you place the knife on the wedge to set your angle and you are good to go….. or are you?
Some knives have a full flat section on which to rest the blade when setting the angle, but many do not; for example, look at the blades on this Case Seahorse Whittler.
I did not measure any angles from the factory, but… The factory blade has a long bevel to the spine around 10° with the secondary bevel near 27°; so about 17° between the primary and secondary.
Without thinking, I placed the blade onto a 13° wedge, which created a secondary bevel near 23°. Again, without thinking, I used my Spyderco Sharpmaker to set a 15° angle but it was not getting sharper because I was removing metal far from the edge.
The only available reference surface is already at 10° so I need a reference angle near 3° to get a 13° final angle.
Where else do you need to worry about your reference angle? One of my favorite sharpeners is the Work Sharp sand paper belt sharpeners, I own a couple versions. The Ken Onion version with the Blade Grinding attachment has a flat reference surface. The idea is that you set your blade on the reference surface and then hold that reference to get the angle set on the attachment.
https://www.sharpeningsupplies.com/Work ... 31C68.aspx
This is a potential problem with most systems where you are trying to actually measure your angle. The Wicked Edge Precision sharpener looks like it should not have this problem, especially if you are using an angle measuring guide on the bars, someday I will have one to test perhaps. I also do not see this as a problem with the Tormek system that I use, but I have not tried their machine specific to knife sharpening.
Finally, I did not attempt to discuss how different grinds may affect the reference surface.