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Would stropping on glass have a beneficial effect?
- Thread starter MJF
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If the glass were frosted by sandblasting or conditioning with an abrasive grit, you could absolutely use such a strategy.
I recently acquired some AlOx abrasive, coarse and fine, suspended in oil to be used for sharpening microtome blades - on a frosted glass plate. The machine used a fore and aft stroke and ran cycles for extended periods of time. I'm certain it would work, am not sure of the particulars.
I recently acquired some AlOx abrasive, coarse and fine, suspended in oil to be used for sharpening microtome blades - on a frosted glass plate. The machine used a fore and aft stroke and ran cycles for extended periods of time. I'm certain it would work, am not sure of the particulars.
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It would align the edge as a steel does, frosted or not.
I knew a fellow named Bret who did sharpening for the local knife stores and the gun shows. His grinding stations at home were fairly spartan. The kit he carried with him for hand sharpening was most impressive in quality and quantity. The final stage he used on an edge for a fighting blade were glass rods. I don’t remember the type of glass rods used as it has been some time ago. This cat was smart, educated, and tested everything he did to find real world answers. He believed it worked, I always thought is was a bit of overkill.
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I think we have to be careful to differentiate between burnishing such as with a meatpacker's steel, and using the glass as a surface for lapping with a suspended abrasive. Two very different actions going on - the first is a straightforward burnishing, the second is going to work more like a waterstone.
I imagine getting the consistency and quantity of the slurry right would be the biggest challenge, after figuring out what the best surface texture might be...
I imagine getting the consistency and quantity of the slurry right would be the biggest challenge, after figuring out what the best surface texture might be...
He never taught me to use the glass rods. Of course showing somebody something is not the same as teaching them. There may well have been some version of a stropping compound used and added in a subtle way, but I think he used bare glass. Now thinking about it I did not ever see him clean the rods he used, which he most certainly would have done. Something could have been added at this stage.
I have for some time sharpened my own stuff using the usual machines, guides, freehand equip. When he offered to sharpen my primary fixed blade fighter there was zero hesitation handing the blade over to him. He reprofiled using grinders and ice then finished by hand including the glass rods. The rods may or may not have added sharpness to the blade but I think it may have added good juju to my brain, either way it would cut better.
@Heavy
Do you think a stropping compound would be needed using glass as a strop?
I have for some time sharpened my own stuff using the usual machines, guides, freehand equip. When he offered to sharpen my primary fixed blade fighter there was zero hesitation handing the blade over to him. He reprofiled using grinders and ice then finished by hand including the glass rods. The rods may or may not have added sharpness to the blade but I think it may have added good juju to my brain, either way it would cut better.
@Heavy
Do you think a stropping compound would be needed using glass as a strop?
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If you used the glass (rod) like a meatpacker's steel, nearly the entire action would be a fine burnishing. Would be no different from steeling except the surface characteristics of the glass might work in a slightly different fashion from the surface of the steel. It can do an absolutely impressive job of refining an edge very very quickly. It takes a bit of understanding too, if overdone it can draw out the blade steel and leave it work-hardened and prone to brittle failure.
In this context, using a compound probably wouldn't help much unless it was formulated to virtually adhere to the glass - you'd also be backhoning, where most steeling is done into or across the edge. I'm not sure if there would be any real advantage over other forms of stropping and might be more challenging in other respects. If the glass were frosted and the compound was in slurry form, the glass would act as a pretty good lapping board - I've seen the instructions for several types of microtome honing machines that used textured glass to re-sharpen the blades using a back and forth motion on a static plate, or with the blade being worked against a spinning platter. One even had instruction for how to diagnose and refrost the plate with silicon carbide grit when it eventually polished itself smooth and stopped working efficiently. From the instructions I have to believe it makes a very clean and refined edge with no need for further deburring or polishing. IIRC it also takes hours to accomplish anything more than the lightest touch-up, and that's on a powered unit....
The glass used is called 'Borosilicate Glass.'
This is the same glass used for ordinary Pyrex baking dishes, pie plates, measuring cups, etc., sold very cheaply in every good supermarket and home/kitchen supply store. It is also used for all laboratory equipment glass, and car window glass. It's cheaper to produce than home window glass, so do NOT pay fancy high prices for it.
You can use the edge of your wife's meatloaf pan or pie plate, or the edge of your car window.
I had a chemical supply store make up a glass rod for me to use in my kitchen for under $10, and have been using it daily for many years now rather than a metal butcher's steel. I prefer the results, but keep in mind that you can drop a metal butcher's steel twice. You can only drop a glass one once...
But that is different from using glass as a stropping substrate. While the hardness is perfect, and the flat surface just what we need, the glass won't 'hold' the abrasive of the compounds very well. If you are polishing two large flat pieces, it will work. But if you are trying to localize the abrasion to just the edge of the blade, it will push or pull the abrasive out of the way rather than riding over it giving the desired effect.
Stitchawl
This is the same glass used for ordinary Pyrex baking dishes, pie plates, measuring cups, etc., sold very cheaply in every good supermarket and home/kitchen supply store. It is also used for all laboratory equipment glass, and car window glass. It's cheaper to produce than home window glass, so do NOT pay fancy high prices for it.
You can use the edge of your wife's meatloaf pan or pie plate, or the edge of your car window.
I had a chemical supply store make up a glass rod for me to use in my kitchen for under $10, and have been using it daily for many years now rather than a metal butcher's steel. I prefer the results, but keep in mind that you can drop a metal butcher's steel twice. You can only drop a glass one once...
But that is different from using glass as a stropping substrate. While the hardness is perfect, and the flat surface just what we need, the glass won't 'hold' the abrasive of the compounds very well. If you are polishing two large flat pieces, it will work. But if you are trying to localize the abrasion to just the edge of the blade, it will push or pull the abrasive out of the way rather than riding over it giving the desired effect.
Stitchawl
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For sake of the discussion, here's the manual for a microtome sharpener that uses a frosted glass plate and AlOx slurry. My Father in Law gave me some bottles of the slurry, but does not have the actual machine. The images of it with the skins off give an idea of what sort of action it uses - an elongated S, mostly fore and aft and flips the blade after a set number of passes or time.
http://www.science-info.net/docs/AO-Spenser/AO-935-Knife-shaperner.PDF
I haven't had a chance to take a look at or play with the slurry, but at some point will prep a glass plate and give it a try.
Martin
http://www.science-info.net/docs/AO-Spenser/AO-935-Knife-shaperner.PDF
I haven't had a chance to take a look at or play with the slurry, but at some point will prep a glass plate and give it a try.
Martin
"Frosted" glass should be able to hold a compound nicely. Plain glass not very well.
Stitchawl
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If it were smooth you'd get zilch for results. According the F in L there are other microtome sharpeners that use tincture of green on a borosilicate plate for a final burnishing/polish, but I have to imagine the platter is somewhat textured or grooved.
Opposite to make a point - If you put WD-40 on the rod would that not make it worst?
How much pressure to use? On leather a light touch can go a long way. I watched this old bear of a guy with some large stones use more force than I thought was safe (knife sharpening). He got good results. Glass rods with some basic support would allow for, if needed, a fair amount of force.
"It takes a bit of understanding too, if overdone it can draw out the blade steel and leave it work-hardened and prone to brittle failure." I have heard this in reference to knife sharpening from a reliable source that was not speaking to glass as much as the final stages of sharpening. My question is how in the world would you guys know about this stuff; a enterprise level microscope, dousing, channeling ramtha the enlightened atlantean, how? ...lol...
The microtome sharpener is the new definition of nifty. It is like 2020 tech from the 60's The Jetsons Show; far-out. When you go to bed your phone charges wirelessly, automatic watches are in their winder, and your knives are set for hair-splitting. What a way to start the day. Ahh, the future from the 60's perspective, perfect.
The Hair Splitter 2020 Knife Sharpening Robot - aka Mr. Microtome
yep, don't think I would leave this robot alone with my wife, it has that look.
How much pressure to use? On leather a light touch can go a long way. I watched this old bear of a guy with some large stones use more force than I thought was safe (knife sharpening). He got good results. Glass rods with some basic support would allow for, if needed, a fair amount of force.
"It takes a bit of understanding too, if overdone it can draw out the blade steel and leave it work-hardened and prone to brittle failure." I have heard this in reference to knife sharpening from a reliable source that was not speaking to glass as much as the final stages of sharpening. My question is how in the world would you guys know about this stuff; a enterprise level microscope, dousing, channeling ramtha the enlightened atlantean, how? ...lol...
The microtome sharpener is the new definition of nifty. It is like 2020 tech from the 60's The Jetsons Show; far-out. When you go to bed your phone charges wirelessly, automatic watches are in their winder, and your knives are set for hair-splitting. What a way to start the day. Ahh, the future from the 60's perspective, perfect.
The Hair Splitter 2020 Knife Sharpening Robot - aka Mr. Microtome
yep, don't think I would leave this robot alone with my wife, it has that look.
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Opposite to make a point - If you put WD-40 on the rod would that not make it worst?
How much pressure to use? On leather a light touch can go a long way. I watched this old bear of a guy with some large stones use more force than I thought was safe (knife sharpening). He got good results. Glass rods with some basic support would allow for, if needed, a fair amount of force.
"It takes a bit of understanding too, if overdone it can draw out the blade steel and leave it work-hardened and prone to brittle failure." I have heard this in reference to knife sharpening from a reliable source that was not speaking to glass as much as the final stages of sharpening. My question is how in the world would you guys know about this stuff; a enterprise level microscope, dousing, channeling ramtha the enlightened atlantean, how? ...lol...
The microtome sharpener is the new definition of nifty. It is like 2020 tech from the 60's The Jetsons Show, far-out. When you go to bed your phone charges wirelessly, automatic watches are in their winder, and your knives are set for hair-splitting. What a way to start the day, ahh, the future from the 60's perspective; perfect.
The Hair Splitter 2020 Knife Sharpening Robot - aka Mr. Microtome
yep, don't think I would leave this robot alone with my wife, it has that look.
I did some noodling with steeling and some help from the microscope at work. You always want light pressure when steeling on steel or glass.
http://www.bladeforums.com/forums/s...e-look-at-steeling?highlight=Quick+close+look
Below is the first post from the link above.
That is too cool.
You say that the pressure was so light but the result seems very pronounced. I wonder does this mean that a similar slight force will remove the steeled edge?
"most notably the pitch of the sound it made going through newspaper became higher and more uniform." Puts a smile on my face...
Some of the stuff I read on this site does make my head hurt, but I can't stop - its like Coloradoian Knife Crack
That is too cool.
You say that the pressure was so light but the result seems very pronounced. I wonder does this mean that a similar slight force will remove the steeled edge?
"most notably the pitch of the sound it made going through newspaper became higher and more uniform." Puts a smile on my face...
The recent discussion re steeling with Stitchawl spurred me to take another look at this practice. Until now my experience with this activity has been largely limited to kitchen knives using a groved steel and a "smooth" one that had become discolored and somewhat abrasive. I've gotten poor performance when using the smooth one on the harder steels found in most pocket/hunting cutlery, even though I still use them on my softer kitchen knives with good results. Having taken a close look at many fresh and worn knife edges, I have never been comfortable with the "re-alignment" theory that is most often applied to the practice, so what is happening?
I realize Verhoeven among many others have covered this topic already, but I have not. Here goes. Based on the micrographs and cutting tests I have a couple of observations. My test knife is a EKA H8 in 12C27 Sandvik. It was sharpened up to the fine side of a Norton Crystalon stone and deburred with the oil and swarf from the stone applied to newspaper (the best wayI know of to do a thorough deburring and not affect the grind structure). Test knife could shave arm hair and just dry shave facial stubble, though not clean to the skin. Could easily crosscut newspaper with a push cut, though sounded quite abrasive when doing so.
The steel is smooth, though not mirror smooth. I cleaned it up thoroughly and polished it with white compound - very shiny and feels very slick when steeling. Pressure was very light, just enough to maintain contact.
Pictures are at 160x and 640x
First two are fresh off the stone and paper:
Next two are after 5 passes on the smooth steel, increasing the angle only a degree or two. The edge exhibited a modest but obvious improvement on the stated tests relative to the starting edge - most notably the pitch of the sound it made going through newspaper became higher and more uniform.
Last two are after 45 passes, some of the conventional wisdom suggests this could harm the edge. Testing showed a large improvement in cutting characteristics - dry facial stubble flew off my cheek without irritation and I was able to rapidly slice 1/4" strips from the crossgrain newspaper. Still no real evidence of burr or wire edge creation, though there appears to be something sporadic - visible lower right in the 160x pic that makes me think they're starting up in some spots...
It is my opinion based on this test that steeling is in fact a form of sharpening (I have come to think of it as the opposite of stropping but achieving a similar outcome, and it quite possibly is realigning the edge, but I have to think this effect is minor compared to the "smoothing" effect I'm observing) using plastic flow instead of grinding to accomplish its goal. I can come up with no other explanation for what I'm seeing. The steel is not removed, but smeared/pressed/squashed, something that Verhoeven among others has already observed to some extent - unlike Verhoeven I observed no breakout of the apex and even after 45 passes I do not see any apex deformity that cannot be traced back the original grinding - this was a surprising find. I do suspect I could have stopped at 10-15 passes and perhaps gotten the best result I was going to get, but wanted to see the effect of too many passes. Clearly too much pressure would be devastating, esp combined with too many passes.
Done carefully it appears capable of significantly improving a lightly worn edge or coarsely sharpened one. I'll have to do some more work on this using a more refined edge and see what the effect is. It may be (and makes perfect sense) that the more refined the edge the more important it becomes to use a glass steel, or one with very exacting surface treatment (has anyone tried chrome?)
This is fast and effective - I'll be giving it a try on some of my larger knives next.
Some of the stuff I read on this site does make my head hurt, but I can't stop - its like Coloradoian Knife Crack
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Below is the first post from the link above.
That is too cool.
You say that the pressure was so light but the result seems very pronounced. I wonder does this mean that a similar slight force will remove the steeled edge?
"most notably the pitch of the sound it made going through newspaper became higher and more uniform." Puts a smile on my face...
Too many passes appeared to be causing the edge to deform a bit, and this was the lightest pressure i could manage, probably only an ounce or two. Based on the fact that it was smearing the steel, I believe it was "drawing" out and had to be weakening - that apex also looked like it was starting to round over a tiny bit. Additional effect on the steel from all that action would be work hardening, setting up brittle failure. Plenty of folks have noticed microchipping etc when certain metals get steeled too much. Some strange things happen when burnishing, is a potent mechanism but difficult to tell if you've gone too far, not far enough, if the edge is in good enough shape to benefit from it or if you need to go back to a stone etc - much experience needed. I don't use my smooth steel very much anymore, but my Washboard is capable of some modest burnishing when used with plain paper, a heavy hand, and a bit of extra speed. Not as pronounced, but with a much larger margin of error.
These are from another thread but show what I'm talking about. The ripple in these pics compared to the other ones is caused by small vibrations from the floor - some of the shop equipment was running nearby. Keep in mind that's the same spot on the edge in these two pics - almost unrecognizable just from stropping on paper - the tops of all the grind troughs are flattened out, the edge itself is noticeably more refined. I haven't observed this from too many other mechanisms - wouldn't trade my Washboard for anything!
On to the 600 grit,straight off the sandpaper - cutting even better than the 320 grit with paper stropping, at least in terms of fine cutting - will now crosscut paper noisily but confidently, still plenty of bite. A real good kitchen utility edge. Can shave arm hair a little better, almost clean.
And after stropping with paper, about 30 passes with moderate pressure. A very nice jump up in cutting ability - now crosscutting paper quietly yet still plenty of 'catch' to the edge. Shaving arm hair cleanly, still three finger sticky.
