- Your cart is empty
- Continue Shopping
Before showing you the gestures necessary to sharpen a knife or a sharp tool, it is necessary to understand what happens during the sharpening action.
The sharpening stone having been wet, rubbing the edge of the tool allows the garnet dust that makes up the coticule stone to disintegrate and mix with the sharpening water.
At this time the water takes on a purplish color.
It is this abrasive water + garnet mixture that allows sharpening.
We point out that garnet dust is almost as hard as diamond. You then understand why rubbing the cutting edge on the Coticule Stone produces wear on the tool.
It’s sharpening.
A sharpening stone with a fine grain is preferable (Coticule Stone type).
The dust that composes it gives it a grain of 1500.
The stone has the two essential qualities of a very good natural stone: finesse and abrasiveness.
The stone is simply used with water for personal or professional use.
The main knife blade steels are:
Carbon steel, fairly soft and easy to sharpen.
It requires regular maintenance
Very hard stainless steel, quite easy and time-consuming to sharpen.
It requires the use of a fine and very abrasive stone.
The 44 steel called surgical which sharpens very well with a fine and abrasive stone like the coticule.
12C27 steel or sandwich. These steels, which are softer than stainless steel or 440, give excellent results when sharpening.
In order to be sharp, the steel blade of your knife has a cut or grind shape, the 2 main ones are:
The flat or slightly curved grind from the back.
The classic V-shaped grind found on many knives including Laguiole knives.
It is therefore the extreme part of the blade that must be sharpened on the whetstone.
Before using the stone, make sure the cutting form is in good condition.
If it is really damaged, in order not to scratch your stone, it may be necessary to restore it to a suitable shape using a water, hand or electric grinder.
You can also obtain the same result by using a flat file called “bastard” with fine teeth.
For this, it is useful to clamp the knife in a vice, the file must “return” into the cutting edge until the correct cut shape is obtained.
These operations being delicate, we recommend that you first practice on an old knife.
Your blade is now ready to be sharpened.
Sharpening of pocket knives or small kitchen knives.
In any case, when we sharpen we must have a fixed point. For small knives it is the stone which must be fixed, for large knives it is the knife which will be fixed but we will talk about it later. The fixed point allows you to respect the angle of the cutting shape of your knife.
Which angle to respect ?
We recommend an angle of around 25°.
Why a 25° angle?
A 25° angle will allow your knife to cut well and for a long time. A steeper angle of 15° for example will weaken the cutting edge.
How do you find that 25° angle?
It’s very simple: by observing the diagram below. All you have to do is present the knife perpendicular to the stone. You then have an angle of 90°.
By dividing the angle by 2 then again by 2 you arrive at the sharpening angle of 25°.
Now let’s get to the sharpening action.
The stone is fixed and well moistened with water, the angle is found, you just have to rub the blade sharpening hard going up and down without lifting the blade and without varying the angle.
You first sharpen the straight part of your blade by guiding you on the edge of the stone, then by a movement in an arc you sharpen the rounded part to the end of the blade, always pressing hard and keeping the angle .
After sharpening one side of the cutting edge you turn the knife and sharpen the other side of the cutting edge by making the same movements.
It is difficult to give the necessary time for a good sharpening.
It all depends on the condition of your blade and the quality of the steel.
A stainless steel or 440 steel blade will take longer than a carbon steel blade.
When you touch the cutting edge, you will estimate whether it is necessary to insist.
Sharpening large kitchen knives
The tool to be sharpened becomes the fixed point.
All you have to do is hold it firmly on a corner of a table or workbench and after having wet the stone, you rub it on the blade in a circular motion on each side of the cutting edge, respecting of course an angle of approximately 25° and pressing hard.
Sharpening Scissors
Be careful, each branch of the chisel has only one cutting edge. It is therefore this cutting edge that must be sharpened by a circular movement.
After sharpening the edge, it is necessary to push back the slight burr that appeared on the flat side of the branch, laying the stone flat on the branch of the chisel. Perform the same operations on the other branch of your chisel.
Also in this case, the chisel must be held fixedly open in order to adhere to the cutting angle of this tool.
In summary, we give you below the 4 rules to respect for a good sharpening with the whetstone.
- The fixed point
- Wet the stone well
- Respect the angle
- Press hard
Tips from the grinder
- The fixed point is very important.
- When sharpening a small knife or a folding knife, position either your thumb or your index finger in front of the axis of the blade, so you can exert more pressure on the blade (see sketch). You can also help yourself by pressing with a finger of your left hand to rub the blade harder on the stone during the sharpening action.
- We stuck a strip of leather on the lid of our boxes, after sharpening on the stone, pass the 2 sides of the blade on the leather by pressing a little hard and this in the direction of the grain. You will get a better finish, the leather having straightened the slight burr that remains after passing on the stone.
- After use, the stone will be cleaned with soap and water.
- Do not wait to maintain the blade of your knives, the regular use of the whetstone will maintain the shape of the cut.
The abrasive properties of the whetstone allow it to be used in many and very diverse fields:
Professionals: Cutting tools for woodworking, gouges, plane blades, wood chisels, etc. Leather trades, farriery tools, hoes, frogs, catering trades, agriculture, printing, etc.
Hobbies: Knives and daggers for hunting, knives and hooks for fishing, sharp tools for gardening, secateurs, axes. Small tools for making models, etc.