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Edge profile theory
- Thread starter 51ayer
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Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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I like a slightly convexed edge on most blades. This makes a more robust edge that holds up to rough use.
Most of the time I do the main bevels, and add the edge bevel on the slack belt at 400 grit to get this edge.
On very thin knives, like fillet blades, I use an FFG to the edge. After the bevels are ground to a near zero edge, I add a tiny edge bevel.
with a sharpening stone or the rotary platen.
Most of the time I do the main bevels, and add the edge bevel on the slack belt at 400 grit to get this edge.
On very thin knives, like fillet blades, I use an FFG to the edge. After the bevels are ground to a near zero edge, I add a tiny edge bevel.
with a sharpening stone or the rotary platen.
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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7-10DPS
How does the slack belt affect the convex, polishing?
I have read about and seen the slack belt used to achieve a hollow ground edge on thin blades. I have little to no experience with the slack belt I primarily use wet stones.
Would it be possible to get a hollow ground effect on a heavier blade?
I have read about and seen the slack belt used to achieve a hollow ground edge on thin blades. I have little to no experience with the slack belt I primarily use wet stones.
Would it be possible to get a hollow ground effect on a heavier blade?
Most of my fillet knives are between 15° and 20°.
Willie71
Warren J. Krywko
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How does the slack belt affect the convex, polishing?
I have read about and seen the slack belt used to achieve a hollow ground edge on thin blades. I have little to no experience with the slack belt I primarily use wet stones.
Would it be possible to get a hollow ground effect on a heavier blade?
A slack belt will give you the opposite (convex) of hollow ground (concave.)
Willie71
Warren J. Krywko
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I use the edge pro on the lowest angle setting which is 9dps, but I have ffg on most kitchen knives, and I don't shim them to flat, so it will be a couple degrees lower. You need steel that can support this fine edge and dialled in heat treat.
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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My fillet blades are very sharp and used by people who fillet with skill. They are usually .06 to .09" thick at the ricasso. They are made in CPM-S35VN, so they can support the very thin edge. On a slicer that will get more general use, I go up to 15° per side.
A pointed out by willie, a slack belt can not make a hollow grind. It makes a convex grind. You need a contact wheel or a curved platen to hollow grind. A hollow ground edge would not be a good edge in my opinion. It would be very quick to dull, and would have an inherent drag.
A pointed out by willie, a slack belt can not make a hollow grind. It makes a convex grind. You need a contact wheel or a curved platen to hollow grind. A hollow ground edge would not be a good edge in my opinion. It would be very quick to dull, and would have an inherent drag.
Due to sharpening and stropping any edge will become convex, and it stands true also for straight razors where the sharpening angle is fixed by the spine resting on the stones.
For knives, hand sharpening will increase the convexing factor.
I prefer a full flat bevel and a "naturally" convexed edge.... IMHO if you can spot a convex edge by looking at the bevel you are entering the realm of choppers and axes
Depending on the blade, you should find out the thinner edge and the lowest angle that will hold up to the knife intended use. It is a trial & error process where slight variations have profound effects.
For knives, hand sharpening will increase the convexing factor.
I prefer a full flat bevel and a "naturally" convexed edge.... IMHO if you can spot a convex edge by looking at the bevel you are entering the realm of choppers and axes
Depending on the blade, you should find out the thinner edge and the lowest angle that will hold up to the knife intended use. It is a trial & error process where slight variations have profound effects.
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Most of my knives have a "Hand-Planed-Jigless-Flat-Grind"... meaning, I try for flat but they never are because I'm a human. So inevitably, they become slightly convex(very shallow)... which was my plan from the start!
Bush knives get a secondary bevel which is ether done by hand or on a slack belt with a light touch. It too, is convex(are you picking up a theme?) Kitchen knives are usually ground to zero with only a few swipes(around 5-7DPS) to set the final edge. It is expected that the user will find their own sharpening angles. I offer my ideas as to how to take care of their new knife but for most folks, it is a matter of personal preference.
I will say this... I often use a slotted paper wheel to polish the edge. It took a while to get used to but, MAN! Kitchen knives also get a fine ceramic rod ran across the edge for that scary sharp toothiness.
By the way... if you use the term "Hand-Planed-Jigless-Flat-Grind" in text, print or general conversation... you owe me $5. Even if you unconsciously think it to yourself, you owe me $2.25.
Bush knives get a secondary bevel which is ether done by hand or on a slack belt with a light touch. It too, is convex(are you picking up a theme?) Kitchen knives are usually ground to zero with only a few swipes(around 5-7DPS) to set the final edge. It is expected that the user will find their own sharpening angles. I offer my ideas as to how to take care of their new knife but for most folks, it is a matter of personal preference.
I will say this... I often use a slotted paper wheel to polish the edge. It took a while to get used to but, MAN! Kitchen knives also get a fine ceramic rod ran across the edge for that scary sharp toothiness.
By the way... if you use the term "Hand-Planed-Jigless-Flat-Grind" in text, print or general conversation... you owe me $5. Even if you unconsciously think it to yourself, you owe me $2.25.