Sharpening conspiracy!

[Eshmiel]

I see that knife sharpening madness is getting to you!
Why on earth would a so called "Scandi"edge produce a better result than any other "configuration" - given the same angle at the sharp end. It makes no sense at all. If there is any difference it can only be in the differing technique used to produce the angle, one perhaps being more effective than the other.
Why would a convex edge be stronger - for the same edge angle the convex edge takes away more metal and must be weaker?
Obviously poorly made or poorly designed knives are less good - by definition.
What about a well made and well designed knife with "poorer" steel? Wouldn't that just mean easier sharpening but faster blunting?
I can see the point of a laminated knife with hard centre and softer outer. This is common with older chisels and plane blades; hard face attached to soft back and slightly easier to sharpen.

Are you teasin' me now, you rascal? I cannot believe that you would be so unaware of these knife bevel profile matters as to dismiss them out of hand.

Even if you think logically about the shape of the knife bevels and how they would affect various kind of cutting attempts on various shapes of surface, you would surely grasp the reasons for these different grinds. Actually carve something and the differences become irrefutable.

But if you can't be bovvered ..... perhaps I'll write a post of not less than 1000 words to explain.

 

[Jacob]

....

But if you can't be bovvered ..... perhaps I'll write a post of not less than 1000 words to explain.

I might have a go at carving. I've got a Mora knife a hook knife and various gouges. I'd guess that a normal rounded bevel would be best, and it's easiest.

 

[Eshmiel]

I might have a go at carving. I've got a Mora knife a hook knife and various gouges. I'd guess that a normal rounded bevel would be best, and it's easiest.

You'll discover that the rounded bevels will tend to force you to make cuts at too steep an angle to take very thin shavings from many surfaces. BTW, you'll also find it advantageous to have one knife longer than the other and one with a very sharp point and both a curved edge and a straight edge and hook knives of different curvatures and .......

On the other hand, you may be so skilful that you can make a fine and elegant thing with nowt but a blunt & rusty Swiss Army knife. I hope to see this item here soon, including the close-ups.

************

That reminds me - can you point us to some posts picturing some of your wooden productions?

 

[Jacob]

You'll discover that the rounded bevels will tend to force you to make cuts at too steep an angle to take very thin shavings from many surfaces.

Not for the same edge angle. The rounded bevel gives you more control, it's rounded under the edge angle and effectively finer than a flat bevel edge with the same angle

BTW, you'll also find it advantageous to have one knife longer than the other and one with a very sharp point and both a curved edge and a straight edge and hook knives of different curvatures and .......

On the other hand, you may be so skilful that you can make a fine and elegant thing with nowt but a blunt & rusty Swiss Army knife. I hope to see this item here soon, including the close-ups.

************

That reminds me - can you point us to some posts picturing some of your wooden productions?

I did a show some years ago - bits of furniture here, a departure from my main business which was period joinery, mainly sash windows and panel doors. Website totally out of date, keep meaning to revise it.

 

[Eshmiel]

Not for the same edge angle. The rounded bevel gives you more control, it's rounded under the edge angle and effectively finer than a flat bevel edge with the same angle

I can't follow that. Can you draw a diagram of what you mean? "Rounded" bevel. Do you mean "convex"?

The reason for wanting a flat bevel to the carving knife edge is the same reason that a flat bevel all the way to the edge is wanted in a carving chisel or gouge - the flat bevel acts as a jig in the same way as the flat back of a paring chisel acts as a jig - to keep the edge at a very shallow angle to the work to take very thin slices. Any rounding in the bevel, or a microbevel, prevents this. For the edge to bite with a convex bevel it must be pivoted all the way off the bevel, so paring cuts will be taking thicker slices because of the steeper presentation of the edge to the work.

Convex grinds won't stop you carving but they will limit the ability to pare and are generally harder to steer through a cut because of the variable bevel pressure as the bevel goes deeper into the cut.

Here's an explanation by Robin Wood:

https://www.robin-wood.co.uk/wood-c...he-best-knife-for-wood-carving-and-whittling/

I did a show some years ago - bits of furniture here, a departure from my main business which was period joinery, mainly sash windows and panel doors. Website totally out of date, keep meaning to revise it.

Some nice pieces on your website, though. Can one charge that much for such things? Perhaps I should stop giving mine away.

But carve a nice spoon with yer knife and lets have some close ups.

 

[Jacob]

I can't follow that. Can you draw a diagram of what you mean? "Rounded" bevel. Do you mean "convex"?

Convex. A new tool is likely to be ground at 25º. I'd start it on the stone at 30º but dip as I go so that it ends up at 25º or less. Edge stays 30º the bevel curves away to less than 30º.

The reason for wanting a flat bevel to the carving knife edge is the same reason that a flat bevel all the way to the edge is wanted in a carving chisel or gouge

They are not particularly wanted on a chisel or a gouge

- the flat bevel acts as a jig in the same way as the flat back of a paring chisel acts as a jig - to keep the edge at a very shallow angle to the work to take very thin slices. Any rounding in the bevel, or a microbevel, prevents this. For the edge to bite with a convex bevel it must be pivoted all the way off the bevel, so paring cuts will be taking thicker slices because of the steeper presentation of the edge to the work.

Convex grinds won't stop you carving but they will limit the ability to pare and are generally harder to steer through a cut because of the variable bevel pressure as the bevel goes deeper into the cut.

Here's an explanation by Robin Wood:

https://www.robin-wood.co.uk/wood-c...he-best-knife-for-wood-carving-and-whittling/

Like so much of modern sharpening it makes sense. That's why it gets such a following. But it's a delusion and much of modern sharpening is flawed and unnecessary so I'd guess this is too. Could be wrong!

Some nice pieces on your website, though. Can one charge that much for such things?

Not many, but then I didn't want to make many!

Perhaps I should stop giving mine away.

Chap sells his spoons on our Saturday market. Seems to be popular I'll take a closer look

But carve a nice spoon with yer knife and lets have some close ups.

Might have a go. I did Robin Wood's bowl carving weekend some years ago. Still got the bowl somewhere.

 

[Eshmiel]

Eshmiel said:
The reason for wanting a flat bevel to the carving knife edge is the same reason that a flat bevel all the way to the edge is wanted in a carving chisel or gouge

They are not particularly wanted on a chisel or a gouge

You'd better inform Chris Pye and several other master carvers then - they've all been doing it wrong and should adopt the Jacob, er, "method".

Eshmiel said:
- the flat bevel acts as a jig in the same way as the flat back of a paring chisel acts as a jig - to keep the edge at a very shallow angle to the work to take very thin slices. Any rounding in the bevel, or a microbevel, prevents this. For the edge to bite with a convex bevel it must be pivoted all the way off the bevel, so paring cuts will be taking thicker slices because of the steeper presentation of the edge to the work.

Convex grinds won't stop you carving but they will limit the ability to pare and are generally harder to steer through a cut because of the variable bevel pressure as the bevel goes deeper into the cut.

Here's an explanation by Robin Wood:

https://www.robin-wood.co.uk/wood-c...he-best-knife-for-wood-carving-and-whittling/

Like so much of modern sharpening it makes sense. That's why it gets such a following. But it's a delusion and much of modern sharpening is flawed and unnecessary so I'd guess this is too. Could be wrong!

Ah ha! Here is you problem You won't let "it makes sense" push out from your wetware the various strange hard&fasts concerning this and that. There's no virtue in refusing to change your mind no matter what evidence is presented to it.

Carve two identical spoons, one with scandi-grind carving knives and then one with knives sporting your convex grinds. Experience will tell you plainly, "You have been labouring under a delusion, Jacob. Whilst you're uninstalling this one, why not sweep away them others?" Experience is a wise woman, so she is.