The various strokes used for razor sharpening
Last updated on: 2013-10-25 07:47
If there's one thing easy about honing razors, it has to be the fact that they all come with a build-in honing jig.
For sharpening the vast majority of knives, the challenging part is to maintain a correct honing angle. Many jigs and fixtures are available to attain this premise, none of which we need for straight razors. Razors simply lay flat on the hone. The honing angle is defined by the thickness of the spine and the width of the blade. The hollowness of the blade provides an arch that allows a steady, wobble-free movement of the blade.
As a general rule, a razor is pushed over the hone with the edge leading. When it approaches the end of the hone, the razor is turned over the spine and pushed back to the starting position where it is flipped over the spine again. Such a complete movement is often called one lap. For achieving the delicacy of a good shaving edge, pressure must be be controlled and even and imperatively minimal near the end of the honing cycle. Certain types of hones really show a reverse correlation between pressure and the keenness that can be reached. Diamond hones such as those made by DMT are an easily observable example of that, but they're not the only hones that ask for nominal pressure.
It is inherent to the production process that a straight razor may show small tolerances in the straightness of the blade and the evenness of the grind. As a result, even if the razor rest stable on a hone that's wide enough to support it completely, the edge may still not be touching the surface along its entire length. Even if a hone can and should be kept completely flat, the smallest amount of "dishing" will result in a less than perfect contact between edge and hone.
For these reasons a strong recommendation must be made not to hone in a straight ahead direction, even if the hone is wide enough to support the entire blade. We simply have a better option that perfectly rules out these issues: the diagonal honing stroke, aka the X-stroke.
For the majority of razors with a straight edge. This is the basic stroke for honing razors. Continually shifts the points of contact that the blade makes with the hone, compensating for small discrepancies in blade geometry and thus effectively assuring that the entire edge receives attention.
2.The swaying X-stroke
For smiling edges. For blades with smiling spine and edge. The heel and toe receive some extra attention.
3.The rolling X-stroke
For blades with light to heavily smiling edges. Adjust the tilt in the stroke accordingly. Can be combined with the swaying stroke.
4. The half stroke
The 3 X-strokes also have an incarnation where they are performed without flipping the blade over. The blade is pulled back to the starting position by reversing the push movement. It stays in constant contact with the hone during the entire stroke, the "push" part of the movement is performed with slightly more pressure than the "pull" part. To control this pressure, one finger is placed on the blade and it exerts some pressure. The pressure is only delivered by the muscles of that finger and not by those of the wrist or the arm. That way the pressure stays in the right range.
Further details about half stroke honing
The half stroke is used to enhance the performance and speed of the sharpening action. It works very well on a Coticule with slurry. It is important to count the laps, since the same amount of laps needs to be copied on the other side of the blade. If a lot of work needs to be done, it's good practice to compare the bevel widths of both sides to each other and adjust the lap count in favor of the smallest bevel face.
Half strokes always need to be followed by 10-20 of its corresponding X-stroke, i.e. the half rolling stroke needs to be followed by 20 rolling X-strokes.
Half strokes are notably efficient during bevel formation stages of honing, due to the improved ability to remove steel. But also on notoriously slow finishing hones, half strokes can make a significant difference.
Practice and Training
The edge is never better than your honing stroke. Even if you get everything else about honing a razor right, if your honing stroke is less than perfect, the resulting edge will be less than perfect too. Like many things related to straight razor use, it takes an amount of persistent practice to really master this. For adopting a good honing stroke it is better to practice 15 minutes daily than to spend one night weekly on a long and nerve-wracking honing session. Once the skill is yours, you won't easily loose it. Cerebral activities like riding a bike, using a computer mouse and honing razors, once learned generally stay with us for the rest of our lives.
The way the wave of fluid behaves in front of the edge, holds important information about your honing. If the fluid runs up a part of the edge, than you can be certain that part is making good contact with the hone and is keen enough to "undercut" the fluid. Parts of the edge that refuse to do this, ask for your special attention. Does that part make good contact with the hone? Is a good bevel fully developed? Do you need one of the special X-strokes to tackle problems with the blade geometry? Does your stroke needs fine-tuning? The wave in front of the edge helps to answer those questions.
If an edge misses a small micro-chip, that usually leaves a fine trail of honing fluid behind. If you spot this, it's always a good idea to closely examine the edge, preferably with some magnification device.
If you accidentally lift the spine (something you should absolutely avoid), you'll be able to hear a sonic difference. Be honest with yourself when such a slip-up happens. It might be necessary to fall back to a previous hone for a few laps, to undo the microbevel you just created by lifting the spine.
When a small grain of a foreign substance ends up at the hone's surface, you can usually hear a grating sound. Stop immediately to clean the hone.
Most of the things that can be heard can also be felt with the fingers that hold the razor.
Moreover, the way the edge is developing can be felt. This is called "feedback". Some types of hones offer a lot of feedback, while other types don't. Seasoned honers often rely more on the feedback than on dedicated sharpness tests. It takes a great deal of experience to acquire such level of mastery.
Additional remarks concerning rolling strokes
There are a few different ways to add a rolling motion the the stroke. Here's a way that keeps you in precise control, regarless you'r doing rolling haofstrokes or rolling X-strokes:
The rolling motion has
to come from the upper arm. Right now, while you're sitting in front of
your view screen, lift your right arm (if
you hone right handed) and raise your fore arm in front of you, parallel
with and above the spacebar of your keyboard. Mimic holding a razor.
Lift your elbow while lowering the wrist, and alternate that motion,
lowering the elbow while raising the wrist. Tell your wife to mind her
The motion you now did is the basic motion that is added to a half- or a full X-stroke to get a rolling stroke. The amount of roll can be very precisely controlled by how much the elbow is raised and lowered. Note that this motion is automatically diminished at the razor, because the elbow sits on the long end of the cantilever that has your pols as a fulcrum.
Many perform the roll slight finger movements. That works well for the X-stroke, but not for halfstrokes because the finger on the blade interferes with that technique. Put the roll in your entire fore arm, and not only you will be able to use the same rolling technique for X-strokes and halfstrokes, but you will be in better control as well.
It is advisable to always put at least a minimal hint of roll in your strokes. On most razors, not so much a real roll is called for, but rather a gradual shift in pressure: first on the heel, over the middle to end on the tip. And the reverse of that while pulling the razor back during halfstokes.
Before starting halfstrokes, always take a moment to seek the right rolling curve for that razor. This can be achieved by performing a few slow X-strokes while closely monitoring how the fluid behaves in front of the edge. Basically, it has to first run up the heel, evolve to running up the middle halfway the stroke and run up the tip near the end of the stroke. 3 or 4 careful X-strokes is generally sufficient to find the right motion and lock it into muscle memory. Next, start the halfstrokes with the same curve. It's good procatice to occasionally stop for checking the edge with a TPT. At that point, re-calibrate the stroke in the same way as described above.
Some considerations about bevel correction with a Coticule.
While correcting the bevel, don't worry too much about a constant repetition of identical strokes. If a TPT reveals that part of the blade stays behind, just put a finger above that part. If the issue persisis, consider to make partial strokes that only work the affected portion of the edge.
It is key to regularly check the shape of the bevel, how easily the slurry runs up the bevel, if the edge sits more of less in the center of both bevel faces. A bevel always tells a story with the the shape it takes. It might tell you there's some warp in the razor. It might reveal uneven spots in the grind (often found in razors that were heavily sanded during a restoration process). It might tell you that the spine is thinner near one end. It might tell you that a frown is developing, or an exaggerated smile. It might reveal a slight loss of bevel symmetry. At first, it can be difficult to decipher the language of the bevel, but with experience it becomes second nature and in most cases possible to tell what's going on with a quick inspection.
As always the case with abrasive action, we have to work at the high spots and omit working at the low spots. If that calls for working only the tip or heel half of a blade, or favoring one side of the blade more, than we must not hesitate to do so. By the time we call the bevel good, it must be good. It defines how easily the edge can be turned into perfect shaving condition - and kept that way - for years to come. We must stay at the helm while sharpening a razor and continuously steer the process till we arrive exactly at our desired destination.