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Dawn liberation of hard Jnat honing

I'd be the first to admit that I have a large number of finishing stones. Enough that I've been able to forget about a couple of them. Not because I can't keep track of them, but because they are really really extra hard. They do a beautiful job, except that they have a bad habit: at about the time that everything gets just exactly perfect, the razor sticks or something, for just an instant, and takes a little gouge out of the edge. Usually in a narrow band, for a few mm. Time to start over!

You can imagine that I have not been eager to repeat this experience, however great the edges I get when this catastrophe does not happen. So I've had two stones in durance vile, waiting for the day when I could find the way to set them free.

I've tried everything with this pair of stones. Being gentle. Not being gentle. Making sure I have plenty of slurry. Not making sure I have plenty of slurry. Torqueing. Not torqueing.

Finally I got my hands on a Morihei Ozuku, which showed all sorts of signs of being a top-class razor finisher, but it started showing early signs of this sticking behavior. I stopped, and contemplated, and remembered a piece of advice I'd read here: try involving some dish soap. So I added several drops of Dawn to my spray bottle, shook it up, and sprayed. It worked! That bit of extra lubrication, along with some due care, was all I needed. Now I can use my hardest stones again! Very happy about this.

I guess it won't make it into the Dawn ad campaigns, though. I might go through 1/100 of a bottle of Dawn per year.
 
I can’t believe that I’ve never thought to put the soap directly into the bottle! Genius.

I’ve ditched the spray bottle in favour of one of these lab wash bottles. It works great. It shoots out a very fine and precise stream of water. It’s easy to regulate the flow from a few drops to a full flush.

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I shall remember this, ta.

I don't want to derail your thread but... would you (or someone else) be able to briefly explain to me what 'torqueing' during honing is?
 
I’ve ditched the spray bottle in favour of one of these lab wash bottles. It works great. It shoots out a very fine and precise stream of water. It’s easy to regulate the flow from a few drops to a full flush.

I'd try that in a second, had I not discovered my dream spray bottles made by Pressol, and sold by Obsessed Garage. All the control I want, and then some.
 
Basically putting a slight twist on the tang so that you get a bit more pressure on the edge and less on the spine.

Ah gotcha, cheers!

I started doing this sometimes a few months ago, just from experimenting as I go along. A couple of my SRs seem to benefit from it, others not so much.
 
You can't really effectively torque the other way. Using that method relies on the flexibility of the blade near the apex. Torquing toward the edge can flex the blade a bit, which actually ends up cutting the bevel wider, and hitting further from the edge. However, subsequent lighter strokes are then focused right at the apex. Torquing toward the spine won't accomplish anything other than lifting the edge off the hone/stone since there's no real flexibility in the spine.

OP, try a little glycerin in your slurry (or just with water) too, it has given me some very good results with some stones.
 
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I'd be the first to admit that I have a large number of finishing stones. Enough that I've been able to forget about a couple of them. Not because I can't keep track of them, but because they are really really extra hard. They do a beautiful job, except that they have a bad habit: at about the time that everything gets just exactly perfect, the razor sticks or something, for just an instant, and takes a little gouge out of the edge. Usually in a narrow band, for a few mm. Time to start over!

You can imagine that I have not been eager to repeat this experience, however great the edges I get when this catastrophe does not happen. So I've had two stones in durance vile, waiting for the day when I could find the way to set them free.

I've tried everything with this pair of stones. Being gentle. Not being gentle. Making sure I have plenty of slurry. Not making sure I have plenty of slurry. Torqueing. Not torqueing.

Finally I got my hands on a Morihei Ozuku, which showed all sorts of signs of being a top-class razor finisher, but it started showing early signs of this sticking behavior. I stopped, and contemplated, and remembered a piece of advice I'd read here: try involving some dish soap. So I added several drops of Dawn to my spray bottle, shook it up, and sprayed. It worked! That bit of extra lubrication, along with some due care, was all I needed. Now I can use my hardest stones again! Very happy about this.

I guess it won't make it into the Dawn ad campaigns, though. I might go through 1/100 of a bottle of Dawn per year.
I have a really hard Shobudani that got a little sticky even with light slurry. This particular stone works best if it is lapped before each use. It also work better with some nagura stones then others. I have had grate results if i use my softer Nakayama instead of my matching tomo on this particular stone.
I have had this stone for 7 years. I feel the stone have been getting better with regular use. Is there a chance that there might have been a layer of oxidation that was somehow reducing the performance of the stone? Is it possible that your stone just needs to be lapped to remove some oxidation?
 
You can't really effectively torque the other way. Using that method relies on the flexibility of the blade near the apex. Torquing toward the edge can flex the blade a bit, which actually ends up cutting the bevel wider, and hitting further from the edge. However, subsequent lighter strokes are then focused right at the apex. Torquing toward the spine won't accomplish anything other than lifting the edge off the hone/stone since there's no real flexibility in the spine.

OP, try a little glycerin in your slurry (or just with water) too, it has given me some very good results with some stones.
The stiffness/flexibility of blades with stabilizers will vary from the heel to the toe. This may lead to a larger bevel at the toe relative to the heel, if the torque is constant during the stroke. Smaller blades, especially extra hollow ground razors will be really sensitive to this.
I have made that mistake on one of my razors.

The friction from the stone should be enough to generate enough torque in the blade just by moving the blade with most stones. Really hard glassy stones might need a different approach e.g. by adding a lubricant with with a higher viscosity.
Some torque might be needed to shift the pressure to get an even hit along the edge though.

Glycerin is a good tip. Is there anything else that can be used to change the surface tension on the stone that will not harm jnat’s?
 
You can't really effectively torque the other way. Using that method relies on the flexibility of the blade near the apex. Torquing toward the edge can flex the blade a bit, which actually ends up cutting the bevel wider, and hitting further from the edge. However, subsequent lighter strokes are then focused right at the apex. Torquing toward the spine won't accomplish anything other than lifting the edge off the hone/stone since there's no real flexibility in the spine.

OP, try a little glycerin in your slurry (or just with water) too, it has given me some very good results with some stones.

Torque has nothing to do with flexibility.
I do it to reduce the normal force between the edge and the hone.



 
I too have used dish soap on JNATs and have had excellent results. Funny thing is I feel like its cheating for some reason. I have even taken razors that start to stick on plain water then hammer them with pressure until the stick goes away then finish with soap. Incredible edge that way. I guess I still find using slurry more fun because of the feedback you encounter.

I will add the last razor I did was done on a hard hard ozuuko and finished with dishsoap. hht was excellent but the shave was harsh in the end! goes to show the ultimate test is a shave...
 
“Torque has nothing to do with flexibility.
I do it to reduce the normal force between the edge and the hone.”


With a razor you are making contact at 3 points, the spine, the back of the bevel and the front of the bevel. The goal is to grind the back and front of the bevel flat in the same plane with the spine.

But if you add too much downward force on a hollow ground blade, you can easily flex the blade, the back of the bevel will act as a fulcrum and lift the front of the bevel, (the edge) off the stone, or prevent full contact.

This can easily be seen by inking the bevel with sharpie ink and do a honing stroke with more torque than normal. Look at the bevel and see where the ink has not been removed. On some razors it does not take much pressure to prevent full contact of the bevel at the edge.

You want just enough torque to keep the spine and the bevel flat on the hone. If you torque towards the spine, the spine acts as the fulcrum lifting the bevel and preventing it from making full contact with the stone.

For finishing laps, just thinking about pressure is enough to keep the razor bevel flat on the stone. Pressure is one of those things that is almost impossible to describe and only learn by doing.

You can also torque from heel to toe but that is a whole other thread.
 
Torque has nothing to do with flexibility.
I do it to reduce the normal force between the edge and the hone.




When talking about a razor being honed (wasn't that what was under discussion here?), it sure does. Doing as you describe will not really affect much of anything except lifting the edge from the stone - which can be accomplished just as easily by lightening total pressure. "Lighter than the blade" levels of pressure really aren't necessary anyway in my experience - unless you have a razor with a barely there bevel, have a razor with an extremely thin grind (say less than .008" thickness behind the bevel), or are using tape and hitting only the extreme apex. YMMV.
 
Is there a chance that there might have been a layer of oxidation that was somehow reducing the performance of the stone? Is it possible that your stone just needs to be lapped to remove some oxidation?

Hard to see how. I have a Nanohone NL-10, and I run it over my stones every time, before I hone, so they will stay super-flat (and, where applicable, to make slurry).
 

Steve56

Ask me about shaving naked!
Just some random thoughts:

The NL-10 is pretty coarse. The surface it makes will be fine for knives and tools but you might want a little smoother surface for razors.

Most synth makers fo not recommend soap/detergent on stones. I doubt it would hurt a hard JNat, but you might want to try a few (4-5) drops of Jet Dry instead. This is a surfactant to make your glass ware spot free in a dishwasher.

Good luck!
 
The NL-10 is pretty coarse. The surface it makes will be fine for knives and tools but you might want a little smoother surface for razors.

You're not the first to warn me about this, but I just haven't seen things work that way in the real world. The microscope, my thumb, and my face tell me I'm getting the results I want, using this process.

Update: it seems conceivable that the NL-10, being essentially a bunch of button-shaped metallic bonded diamond stones, presents to the stone very differently than a diamond plate would, the diamonds being partially submerged in metal, rather than bonded to a surface. Certainly running my finger over the buttons is a much much smoother experience than doing the same with a diamond plate.
 
You're not the first to warn me about this, but I just haven't seen things work that way in the real world. The microscope, my thumb, and my face tell me I'm getting the results I want, using this process.

Update: it seems conceivable that the NL-10, being essentially a bunch of button-shaped metallic bonded diamond stones, presents to the stone very differently than a diamond plate would, the diamonds being partially submerged in metal, rather than bonded to a surface. Certainly running my finger over the buttons is a much much smoother experience than doing the same with a diamond plate.

I was talking about NHs on KKF recently, and this fits with the general verdict there. That they could be used well for quite heavy duty flattening, but also on very fine stones indeed. Rather than having, as I do, an atoma combi / two atomas.
 
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