Grinding wheel for sharpening or expert sharpening system for your sword
There are many different interpretations and descriptions of the concept of the sword, depending on the historical period and geographical location, but one thing is certain - it is a long-bladed weapon. We are not going to go into the historical details within the framework of this article.
What comes to mind as the most obvious when you hear the word sword? Perhaps you imagine shashkas, spadroons, sabers, medieval double-edged swords, and finally probably the crown of the blacksmith's craft and the well-known Japanese katana - all of them were invented in order to create weapons of high sharpness and efficiency, as it is a real edged weapon with a very specific purpose.
Yet we are not going to talk about the purpose, but about what you can use to sharpen such a long object, how the very specifications of the blade force you to take one or another approach in choosing a sharpening system, what will be easier, faster and more efficient, and what will actually be the right thing, but probably more expensive and slower.
1. Sword blade features
Sword blades have several technical features that make sharpening quite difficult. The most obvious feature is the length of the blade. The next important feature is the presence of one or two cutting edges. With its length, it is not easy to sharpen even one edge.
In addition to the previous two features, the type and width of the bevels are important. In any case there is a significant amount of metal to be removed and a lot of work to be done when using any tool or sharpening system.
Blade length - as the main specification represents a significant problem. If we compare it to sharpening a regular knife, even with freehand manual sharpening, the abrasives exceed the length and width of the knife, which increases the convenience of sharpening. With the sword sharpening, there is not a single abrasive stone, which can exceed the length and width of the knife in any significant way.
If you consider sharpening a sword with any sharpener with a sharpening wheel, a belt sander, or a grinder with an endless belt, you will find that sharpening this way will not be any less complicated.
Sharpening even one cutting edge is not easy, and when there are two cutting edges, as on double-edged blades, it makes sharpening twice as difficult. Those who have ever tried to sharpen a real dagger will understand how difficult it can be.
The type and width of the bevels will be one of the most challenging points of sharpening itself for a simple reason - in the vast majority of swords, as a rule, the width of the bevels is the secondary bevel itself. In other words, with swords, the cutting edge is formed by zero bevels, almost like on Scandi knives. The only difference would be the much larger width and the fact that on such a blade of a worthy object, no one makes secondary bevels at all. It is blasphemy to think of such a thing.
You should understand that the geometry of the blade may seem simple at first glance, but this impression can be deceptive.
Most swords taper toward the tip, both in width and thickness of the blade, may have convex, straight, and concave zero bevels, and may or may not have a fuller. Blades can be straight or curved, and the list of specifications can be quite long.
Basically, the essence of the question comes down to the fact that during the sharpening of the sword, it is necessary to properly sharpen the entire plane of the bevel and along the entire length of the blade without damaging its uniform convergence to the tip.
2. Technical issues in sharpening
These above-mentioned technical features together make up the challenge of the sharpening process of any sword. As in the past, so today swords are not only weapons but often also objects of blacksmithing art, which have certain technical and aesthetic frameworks.
The length of all swords is different but remains a problem in sharpening. If the length is significant, there is the problem of controlling and holding the sword in position and keeping it in contact with the abrasive. If the contact is unstable, there is a risk of not maintaining the proper sharpening angle.
One can solve this problem by using various technical devices like roller supports, slides with support, or magnetic clamps. The cost of such a solution for individual use can be very high and unreasonable.
The different types of bevels are the second and most basic issue of the whole complex. Any technical or manual method must be properly calibrated for sharpening a particular kind of blade, as explained above.
3. Sharpening methods
3.1. Using a water sharpener
If you think about using a classic sharpener, even a water-cooled one, there is no commercial solution that will provide during sharpening even contact and precise angle control. Considering that it is necessary to change the abrasive wheels, it will be extremely difficult to sharpen a long blade precisely and not make a mistake, even with long grinder clamps. Besides, there is no sharpener with a large enough clamp.
Without a good enough clamp and in the absence of a big support table, the entire quality of the work will depend on experience in using the sharpener and the quality of the sharpening wheel. Even so, this work can be called "quick and dirty," as it is impossible to perform such a task properly and with precision on an average wet sharpening machine.
A sharpener that has an abrasive wheel of sufficient diameter and width with a large contact area and a big enough support table is definitely not a cheap one. Such a device will resemble a grinder with a large contact wheel, which are often used by professional knife makers.
In the worldwide industry, they often use water-sharpening wheels of very large diameters. The power of such equipment, its size, and technological requirements of operation will allow its use only at large enterprises. At these production stages, knives undergo a roughing stage of processing, and we are not talking about sharpening as such at all.
The use of a bench wet sharpener is possible, but for a complete sharpening cycle you will need several grit sizes, and given the possible wear, you will need to adjust the config of the entire sharpening system to get the angles of all planes.
The only thing technically possible to do precisely enough is to create a secondary bevel on the sword blade, but it should not be there by default, because this changes the initial angle of convergence of the cutting edge, and this changes the sharpness and aggressiveness of the cut.
No one in any production facility will deal with your case personally, not to mention deal with it on a serial basis. It is possible to consider the individual use of a bench wet grinder, but it is not cost-effective, and it is wrong from an aesthetic point of view.
It is possible to sharpen a sword with concave bevels on a wet grinding wheel, but only if the bevel is entirely radial and the diameter of the sharpening wheel matches the radius of the bevel. Otherwise, it will be impossible to sharpen. At the same time, the smaller the bevel radius, the larger the diameter of the sharpening wheel should be. Straight and convex bevels can cause significant problems, to the point that the blade can be ruined altogether.
3.2. Using a grinder
The grinder itself is quite a technological and complex device, which as a rule never has ready-made solutions and in some cases can be a sharpening system. It is certainly possible to create a config that can solve this issue, but it requires certain costs and experience in using such equipment.
You have to take into account literally all the parameters of a blade - the length of the blade, the angles of convergence of the bevels and their shape, literally everything that can become a technical problem in sharpening and finishing.
In terms of metal removal efficiency, the use of grinders is the most productive solution.
On the contact wheel and/or with the use of additional rollers, you can produce almost any concave bevels and finish their surface, but you should always take care of possible overheating of the blade. Working on the contact wheel is much more efficient than on any abrasive wheel on classic sharpeners.
You can use a special clamp and a contact pad to sharpen straight zero bevels on a blade that is straight or tapered to the point. You will need three or more tapes depending on what you want to achieve. In this case, it is also necessary to use cooling, even if you take into account the speed control of the grinder engine.
If the sword geometry will have a bend or convex bevels, even the use of a grinder may not solve your issue.
In any case, the final stage of sharpening will require manual finishing to get rid of the burr on the cutting edge. And this is where you will need manual blade sharpening skills more than ever.
Even with sufficient precision of the grinder due to the peculiarities of using endless belts, it is still impossible to achieve the results of the same level of manual sword sharpening.
Trying to produce very thin bevels without cooling or to finish the cutting edge on the belt is not a good solution for quality steel and an expensive blade, as it can affect the image of the knife maker.
3.3. Manual sharpening
Manual sword sharpening on a sharpening stone is very laborious, very complicated, and much less popular than all other modern technological solutions. The experience of sharpening swords manually at the highest level has survived perhaps only in Japan and is tied to one of the most famous types of swords - the Japanese katana.
Some master polishers of past generations served the shogunate, and some of their descendants today are living national treasures, a testament to the incomparable level of experience and knowledge in this field carried by experts through the ages.
In the manual sharpening of curved blades with straight and convex bevels according to the Japanese method, the process is divided into two main steps, 6 steps each if we are talking about machining a new blade from the blacksmith.
At all stages, 6-10 or more different water natural stones and various emulsions can be used. All planes are profiled exclusively by eye based on the experience of the master sharpener. As a result, the sword not only gets a high level of sharpness but also gets an incomparable individual aesthetic look. All planes are profiled with a quality incomparable to any technological devices, and such swords often become national treasures.
Certainly, it does not mean that every sword needs such a level of processing of the entire blade and such a sharp cutting edge. It should only indicate that certain tasks, even with the current level of technical equipment, cannot be performed otherwise than by hand, and that quality can exceed and does exceed machine processing.
A sword is an object that is unlikely to be sharpened by an average user themselves, but not every experienced sword sharpening specialist has the knowledge and skill to sharpen swords properly. Not all experts in sharpening will accept the challenge, without having enough technical equipment and experience to deal with it.
You can not use every sharpening system or individual unit to sharpen anything and anyway you want and consider it correct. Thus, it is possible to use different wet sharpeners for sword sharpening with some limitations. Grinders are productive devices for sharpening certain types of bevels, but their use requires experience, and the use of cooling is highly recommended.
Manual sharpening of good items at the proper level, as a service, can be quite expensive in price and is worth it only for sharpening really expensive blades.
The work of a sharpener on an industrial large-diameter disc: https://www.youtube.com/watch?v=aU6u80Hyw5Y