Sharpening woodcarving knives?

S

Squashfan

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Jun 6, 2012
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Does anybody here know anything about sharpening woodcarving knives. Not a whittler pocket knife but actual carving knives. It is really hard to push the knife through the wood. I think my problem is geometry. This knife is sharp enough to catch the hairs on my arm as I pass the blade over my arm. I watched this vid: http://www.woodcarvingillustrated.com/videos/sharpening-a-carving-knife.html

It looks like they are scandi or zero grinding it. Anybody got any tips?
 
In Scandinavia we use 18-19 degree total edge on a wood working knife for soft wood. 22-24 degree total edge for harder wood. Flat edge of cause, no honingedge.

Your problem seams to be friktion = to steep edge cannot penetrate the material.

A edge is a "wedge". You force the wedge (edge) in to the material to split (whittle). The wedge (edge) must penetrate the material with as low friction as possible. The degree you use on the edge depends on how hard the wood are.

Thomas
 
Thanks for the reply, Edgepal. I am working on two different knives and this info will greatly help me.
 
If you by your self a Mora knife, it hold normaly 22 degrees, 11 DPS. Use that knife in different types of wood so that you get a feeling for the degree - and different types of wood hardness.

If you use a 19 degree edge in soft
wood, it will fast become dull. = the edge is to thin for hard wood. If you use 24 degree edge in soft wood, you get a problem with friktion and you must use more force... :)

Thomas
 
EdgePal said:
If you by your self a Mora knife, it hold normaly 22 degrees, 11 DPS. Use that knife in different types of wood so that you get a feeling for the degree - and different types of wood hardness.

If you use a 19 degree edge in soft
wood, it will fast become dull. = the edge is to thin for hard wood. If you use 24 degree edge in soft wood, you get a problem with friktion and you must use more force... :)

Thomas
Click to expand...

Thomas, thanks for the help. I will dig around for my Mora companion and I may pick up on of the dedicated Mora carvers.

I totally reground the knife to a zero edge on a belt sander and it was rolling over when I cut the wood. (Probably because it is a really soft steel.) So I used a really fine grade of sandpaper (2500) to microbevel it just a tiny bit. I kept raising the spine TINY amounts until it didn't damage the edge when I cut into the wood. Now my problem it that the blade digs into the wood and has gotten stuck trying to take out large chunks. I don't have a high polish on the rest of the blade. Will that matter? Or is it just the edge I should worry about?
 
The degrees are important here - it is a matter about where your force goes when you whittle. Your Vilnius to whittle along the wood fibers - but if your edge angle is high - the force gi IN to yhe wood and across the wood fibers then along them.

When you have a flat edge on, lets say 9 DPS - the knife central line of the blade points 9 degree diagonal out from the wood.
If you use a hooning edge on, lets say 3 degrees - you have an edge on 12 degree - and the central line in the blqde points 12 degree diagonal out from the wood - and more of your force go now IN to the wood. And, you also need to use more force to get the edge to penetrate the wood, that extra power go also in to the wood, across the fibers, not so muxh along the fibers .

Take a piece of wood, use a knife and slide its edge along the wood, change slowly the angle untill the edge starts to whittle. Remember the angle of the blade. Do the same thing with other knifes with other edge angles - and you understand what I try to explain :)
Then, use the knife with the lowest angle and try to remember the force you need to use to whittle - and compare this force against ghe knife with the highest edgeangle and study how they penetrate the wood. The highest edge angle go deeper in to the wood in a steeper angle - and I dont think that it is what you like your knife to do.

Sorry, i am lack of words here, I hope you understand what I try ro explain any way :)

Thomas
 
Squashfan said:
. Now my problem it that the blade digs into the wood and has gotten stuck trying to take out large chunks.
Click to expand...

When you are whittling you typically want to take lighter cuts - trying to take out large chunks generally doesn't work too well.

Thomas covered things pretty thoroughly so there isn't much I can add other than once you get the knife cutting well, pay attention to the advice to strop more and sharpen less. That's my preference, anyway. I strop pretty frequently.

Good luck.
 
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