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Post by ragebot on Jul 20, 2023 20:07:53 GMT
In maybe 20 minutes I put what to me is a very sharp edge on an el cheapo beater blade ($US50 Wakizashi from Amazon) which water filled plastic bottles tremble in fear when I approach with. I also have a couple of other beater blades I will likely wind up using it on.
I am considering upgrading to what I will call $US200-300 (maybe even a little more) swords and am wondering at what price point (which I am equating to sword quality all else being equal) the KO Work Sharp is not the right tool to sharpen a blade and I need to get into more traditional methods.
Also wondering about what seems to be some distain when sharpening with other than whetstones are mentioned. I get it that if you have a four or five figure blade you need to be very careful about damaging it when sharpening, but I have to say the Work Sharp seems to do a bang up job very quickly and so far I am very pleased with it.
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Post by larason2 on Jul 21, 2023 3:04:18 GMT
There's pros and cons to every method, just like anything else. The KO work sharp looks like a slick little unit. Given it's a belt, it will grind pretty flat, maybe even a bit concave given you're sharpening on the flexible part of the band. With any belts that sharpen without a lubricant like water, you have to be careful not to heat the metal too much, because you can throw off the heat treatment. Such a machine can sharpen quickly though, much more than other methods. Personally I prefer water stones, but they also have their pros and cons.
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Post by ragebot on Jul 21, 2023 23:47:08 GMT
There's pros and cons to every method, just like anything else. The KO work sharp looks like a slick little unit. Given it's a belt, it will grind pretty flat, maybe even a bit concave given you're sharpening on the flexible part of the band. With any belts that sharpen without a lubricant like water, you have to be careful not to heat the metal too much, because you can throw off the heat treatment. Such a machine can sharpen quickly though, much more than other methods. Personally I prefer water stones, but they also have their pros and cons. Actually the belt tension on the KO Work Sharp is such that according to the manual you wind up with an apple seed or concave profile. I have seen warnings about the heat issue but after my first time I ignored it since I was spending a lot of time trying to feel if the blade was getting hot and never noticed any temperature differences along the whole length of the blade. Not saying the heat issue can't be a problem on a big belt grinder that also would work much faster but so far it is a non issue for me. I still have a set of nice whetstones and back in the day used them on my pocket knives (never really had a big blade) and I seemed to be able to get them what I will call super razor blade sharp (at least to shave the hair on my arm) but have not reached that level with the Work Sharp yet.
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Post by guillermus on Jul 22, 2023 11:15:54 GMT
The main problem with water (or oil) stones is that you create a secondary bevel, and for a diamond-shaped blade it works fine, but other blades need a concave edge.
When I bought Atlantean I asked for it sharpened, and they sharpened it with a secondary bevel, and I think a concave bevel would have been better. I won't order any more sharp blades unless they come factory sharp. Otherwise I will sharpen respecting the type of edge it should have
With the work sharp you can sharpen a concave edge faster. If at the same time you sharpen you have a bucket with water next to it to cool the blade, it is difficult to ruin the heat treatment.
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Post by larason2 on Jul 22, 2023 12:27:42 GMT
Guillermus, I think you're mistaken. In English, concave means hollowed out, like a cave, and convex means left with a hump, like a hill. Both water and oil stones tend to wear out as they are sharpened, so they either sharpen flat, if you keep flattening them, or convex. A grinder will sharpen concave, because you are sharpening the blade on a wheel, which naturally removes more material from the inner part of the surface than the outer.
It's actually a point of opinion which is better, concave or convex edges. Both can be very sharp. I prefer convex edges though, because I feel they break less easily, and I like the feel of how they cut.
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Post by AndiTheBarvarian on Jul 22, 2023 13:05:01 GMT
The belly of Rex is convex! (Don't ask for the mnemonic for Reichsdeputationshauptschluss!)
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pgandy
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Post by pgandy on Jul 22, 2023 17:05:27 GMT
Before going further, I suggest checking out the tang on that $50 Amazon wakizashi.
“I am considering upgrading to what I will call $US200-300 (maybe even a little more) swords and am wondering at what price point (which I am equating to sword quality all else being equal) the KO Work Sharp is not the right tool to sharpen a blade and I need to get into more traditional methods.”
I would say that depends on your skills and what you are looking for as opposed to price range. I’d be lost without my WS but will not necessarily use it as a stand alone nor for all jobs. Also bear in mind that a convex edge is a vague term as the radius can vary from something barely detectable to more. As for price, I would be willing to subject an Albion, if I had one, to my WS. However, I’d finish the job otherwise to get the finish to match.
I would neither use a stone nor WS to sharpen a katana or similar blade. Early on, I tried to sharpen my first katana and used my trusty Arkansas stones. I made only two passes before checking my work and to my horror I had two streaks running the length on the blade. What I thought was a flat area on the blade turned out in reality to be curved, convex if you will, ever so slightly but convexed. I sick to my stomach at such a mistake. Keep in mind I was new to swords and this was my pride and joy. Not knowing anything better to do, I cleaned the blade and stored for 6 months, maybe longer while I researched the matter. Finally deciding on sandpaper, I went that route and that has been my favourite method ever since. Not my most used method, but favourite. I have not used a waterstone but can’t see basically any difference in that and the flat surface or my Arkansas other than grit size. The WS will give a secondary bevel which is convex, but nevertheless a secondary noticeable bevel. I have gotten around this on occasions with a blade starting at 15° grind, thinning the blade, then advancing by 2½° increments reaching the edge at 25° to achieve the wanted geometry. Then repeated the process as a polishing one, continuously going to a finer belt after reaching the edge. Sometimes finishing with sandpaper, and for sure if resharpening the total job is done with sandpaper.
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Post by larason2 on Jul 22, 2023 19:10:09 GMT
There's actually no significant difference between Arkansas stones and many of the Japanese stones. I recently found out that all quarries that produce sharpening stones in the world use roughly the same type of stone - a type of quartz where the particles are fine. Such deposits are found in Arkansas as they are in Japan. The only difference as to how fine they sharpen/polish is the size of the particles of quartz, which varies by where they are quarried, and what part of the quarry the rocks come from. In Japan, when swords are polished, they roughly shape it with relatively low grit stones, then work finer and finer to remove the scratches of the subsequent grits. It takes an experienced togisho 2 weeks to polish a sword though, so not for the faint hearted! When they do it though, unless a surface is meant to be convex, they polish it perfectly flat. This is done by frequently flattening the stones, which is part of why it is so time consuming.
If you wanted to sharpen your katana with stones, you'd have to start with a stone around 1000 grit (which is probably what most Arkansas stones are at). Even if you have the right stone, it should take a fair bit of time just to get it sharp, considering how often you have to flatten the stone. A togisho usually sharpens with this stone perpendicular to the blade, and with subsequent passes, adjusts the angle until the final stones are all parallel to the blade. It will work if you leave it at ~1000, but there will be a lot of scratches on the katana. To get those out, you need to move through the ~2000 grit, ~5000 grit, ~8000 grit, then the uchigomori finishing stones to complete the polish. On the other hand, you can just give it a secondary bevel and skip the other steps, but even then you would still want to polish the bevel to make it look nice, otherwise you'll see the scratches at the edge. So it's not that easy!
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Post by ragebot on Jul 22, 2023 20:04:17 GMT
Before going further, I suggest checking out the tang on that $50 Amazon wakizashi. Not sure how to check out the tang since the handle is molded plastic and I can only see a hole for one pin maybe 1/3 of the way down but I suspect the tang does not run the full length of the handle. In any case the handle is so short that my pinky finger sticks off the bottom when I use a twohanded grip. I do have a $US70 Amazon wakizashi that does have a longer handle with a fulllength tang.“I am considering upgrading to what I will call $US200-300 (maybe even a little more) swords and am wondering at what price point (which I am equating to sword quality all else being equal) the KO Work Sharp is not the right tool to sharpen a blade and I need to get into more traditional methods.” I would say that depends on your skills and what you are looking for as opposed to price range. I’d be lost without my WS but will not necessarily use it as a stand alone nor for all jobs. Also bear in mind that a convex edge is a vague term as the radius can vary from something barely detectable to more. As for price, I would be willing to subject an Albion, if I had one, to my WS. However, I’d finish the job otherwise to get the finish to match. I would neither use a stone nor WS to sharpen a katana or similar blade. Early on, I tried to sharpen my first katana and used my trusty Arkansas stones. I made only two passes before checking my work and to my horror I had two streaks running the length on the blade. What I thought was a flat area on the blade turned out in reality to be curved, convex if you will, ever so slightly but convexed. I sick to my stomach at such a mistake. Keep in mind I was new to swords and this was my pride and joy. Not knowing anything better to do, I cleaned the blade and stored for 6 months, maybe longer while I researched the matter. Finally deciding on sandpaper, I went that route and that has been my favourite method ever since. Not my most used method, but favourite. I have not used a waterstone but can’t see basically any difference in that and the flat surface or my Arkansas other than grit size. The WS will give a secondary bevel which is convex, but nevertheless a secondary noticeable bevel. I have gotten around this on occasions with a blade starting at 15° grind, thinning the blade, then advancing by 2½° increments reaching the edge at 25° to achieve the wanted geometry. Then repeated the process as a polishing one, continuously going to a finer belt after reaching the edge. Sometimes finishing with sandpaper, and for sure if resharpening the total job is done with sandpaper. Lots to digest in this. I have seen you post about using sandpaper with a mouse pad back before and I did chop up an old mouse pad and aside from the time needed liked the result. I also used a butcher's rod and a leather strop. The thing is I have never been able to get my long blades sharp enough to shave the hair on my arm like I can do with knives I sharpen on a whetstone (but this just be lack of skill on my part). I have never altered the angle grind with my WS but will definitely try your idea. I am still not sure just what the final grind angle should be as I have seen the range from twenty to twenty five degrees for katana like swords. So far I have only used the WS three times and need all the hints about using it I can get. As an aside I have seen two schools of thought about scratches on the blade. For wall hangers they are definitely a no no for me but I doubt I would ever hang a sub $US200 blade on the wall. On the other hand some posts I have seen say scratches lend character to a blade. So far I am mostly interested in how the blade cuts in the vids I make so scratches at the present time are a non issue for me. As for sandpaper sharpening while I agree it has lots of pros my biggest issue (aside from the time) is I need what I will call a really good way to mount the sword. I have seen things like mounting it in a vice or using a clamp on a 2X4 but am open to other ideas. This is a big reason why I am such a WS fanboy, just select the belt, set the angle, plug it in, and put a sheet of butcher paper on the surface you are sharpening on to catch the steel dust and pull the trigger; it is a real no brainer.
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pgandy
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Post by pgandy on Jul 22, 2023 21:17:32 GMT
If there is a pin through the handle in all likelihood it is not a rat tail tang, not to be confused with a stick tang. Something I was concerned about. A butcher’s rod will not sharpen as such, but re-align the edge. I use a chakmak after each session to do the same. I have noticed at times when cutting newspaper a change before and afterwards. That does seem like it lets the blade go longer between true sharpening sessions. I’ve seen this done, come to think of it I have done it too, that is to use the spine of a smaller knife in a pinch for a rolled edge.
I think there is too much to do about edge angle. I’ve gotten shaving sharp edges from grinds of 15°-25°. The more acute angle seems to cut better but the steeper angles last longer and cut satisfactorily for the most part. A good polish is important for the maximum efficiency. Ya, the sandpaper takes time. Before the WS I would take an Accusharp to knock off the edges of an unsharpened Windlass blade and resolve myself to a weekend of work, and sometimes longer. Fortunately refreshing a previously sharpened blade is much quicker. As far as a blade holder goes, I don’t use one. With katana type blades I remove the furniture, lay the mouse pad down placing a strip of sandpaper on top, spray with WD-40, and go at it. I allow the blade itself to select the grind angle, whatever feels natural. I do much the same with other swords if the hilt will come off. Otherwise, I reverse the process of moving the blade over the paper and place the paper on the blade using a small block of padded wood. I have limited work space. The WS saves me much time, but I often end up finalizing with sandpaper paper.
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Post by guillermus on Jul 24, 2023 17:33:53 GMT
Guillermus, I think you're mistaken. In English, concave means hollowed out, like a cave, and convex means left with a hump, like a hill. Both water and oil stones tend to wear out as they are sharpened, so they either sharpen flat, if you keep flattening them, or convex. A grinder will sharpen concave, because you are sharpening the blade on a wheel, which naturally removes more material from the inner part of the surface than the outer. It's actually a point of opinion which is better, concave or convex edges. Both can be very sharp. I prefer convex edges though, because I feel they break less easily, and I like the feel of how they cut. Ops, you're right. Obviously I mean convex, thanks for the clarification. On the other way, if you use the wheel of the grinder to support the blade... Yes, the edge will be concave, but if you put something flat behind the belt, you could get convex edge. I´ve been trying this with a grinder belt of aliexpress (not in my swords, in this moment only with knives) With the edges I think like you, both can be very sharp because it depends on you. I prefer convex because I think that respects better the blades geometry
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Post by guillermus on Jul 24, 2023 17:52:11 GMT
Wakizhasis and katanas are different.
The blades of the Katanas are not really sharpen, they are really ultra polished, at least in all videos I've sheen about the forged and the finished. The Togishi polish the blade with water stones from 600 grit to already 12000 grit, and it takes already a hundred hours to finish it.
I repeat, from what I have been able to see in several videos of Japanese traditional forging
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Post by larason2 on Jul 24, 2023 22:25:09 GMT
Katanas and wakizashis are sharpened. That's the process that takes place with the ~1000 grit stones. After that, the blade is honed and polished, but already with the ~1000 grit stone it is sharp. With all the stones from 1000 grit up, it is important to be careful the higher grit stones don't dull the blade, and part of the process of honing and polishing is checking to make sure they didn't. If you find a higher grit stone dulled the blade, you have to go back to the 1000 grit and start over!
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Post by fullswing on Aug 2, 2023 20:25:29 GMT
Is there any reason to go after the blade grinding attachment for the KO? I am in the market for a machine from WS but I can't decide between the KO or the Mark2, to me it seems the only reason to get the KO over the Mark2 would be if you also wanted the grinding attachment and I can't figure out if, for our use case (sharpening swords), the blade grinding attachment is needed or if we could just make do with the regular belt sharpener.
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Post by fullswing on Aug 2, 2023 20:30:42 GMT
One additional question:
I have a windlass European sword that was not factory sharpened, completely blunted edge.
Would the standard belt sharpener on the KO or Mark2 be able to put an edge on a blade like this? And if not, would the blade grinding attachment for the KO be capable of doing this?
Perhaps that's the reason to go after the blade grinding attachment, but I honestly can't tell from my research if it's possible to accomplish this as an amateur.
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Post by larason2 on Aug 2, 2023 22:40:19 GMT
Fullswing: Probably not. The difference here is that the standard "mode" produces more of a convex edge, though not as much as using water or oil stones, whereas the blade grinding attachment provides more of a concave edge. There are pros and cons of each though, but in general, a convex or "appleseed" edge is considered better for knives and swords. Concave edges, or sometimes called chisel grinds, can be very sharp, but they are prone to getting chips, particularly if you have very hard edges like 1095. If I were to get one, I'd just go with the standard Mk2 or KO, they are probably both equivalent. Personally I prefer water stones though, which I think give more of a convex edge than even the machines like this.
For your second question regarding your Windlass, yes, either should work. On a long blade like a sword, be careful when you're running it through that you don't have a different angle presenting to the machine for some portions of the blade relative to others. I wouldn't chisel grind a sword, but it has been done before!
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Post by fullswing on Aug 2, 2023 23:05:13 GMT
Fullswing: Probably not. The difference here is that the standard "mode" produces more of a convex edge, though not as much as using water or oil stones, whereas the blade grinding attachment provides more of a concave edge. There are pros and cons of each though, but in general, a convex or "appleseed" edge is considered better for knives and swords. Concave edges, or sometimes called chisel grinds, can be very sharp, but they are prone to getting chips, particularly if you have very hard edges like 1095. If I were to get one, I'd just go with the standard Mk2 or KO, they are probably both equivalent. Personally I prefer water stones though, which I think give more of a convex edge than even the machines like this. For your second question regarding your Windlass, yes, either should work. On a long blade like a sword, be careful when you're running it through that you don't have a different angle presenting to the machine for some portions of the blade relative to others. I wouldn't chisel grind a sword, but it has been done before! Wow, this is fantastic information. I really appreciate you taking the time. Before I buy anything it seems I need to do some more research on the water stones you mention, I was drawn to the machines for speed and simplicity but it sounds like it'd be worth my time to properly learn the craft and take up a manual method. Good tip on being careful with maintaining the angle on a long blade. I have been thinking about the dynamics of pulling a 36 in. blade through the WS mechanism and am not sure I would be able to extend my arm long enough while holding down the machine's trigger. So again this is another reason why water stones may be a better fit for me.
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Post by fullswing on Aug 2, 2023 23:09:16 GMT
Another follow-up, if I was to go with a machine from WS:
These machines offer the user a selection of edge angles in the standard mode. I think the range is something like 10 degrees to 35 degrees.
I know it is somewhat up to preference, but what is generally considered a good general-purpose edge angle for european style swords?
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pgandy
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Post by pgandy on Aug 3, 2023 0:16:38 GMT
For my 2¢. First a chisel edge is not another name for a concave grind. It’s a grind that you will find on chisel, single sided. The advantage is a sharper edge for lack of a better description. As an example, if one puts on a 20° grind one gets a 20° edge back. On a standard edge of 20° since it’s applied to both sides one gets a 40° edge. A chisel edge is for special applications and can only be used by the hand it’s designed for.
As for the WS, I have the KO edition. At one time I was considering the Blade Grinding Attachment and looked into it seriously. At the time there was some question about the WS reliably handling it. There seemed to be some overheating and burned out WS while using the attachment and the factory had some suggestions that supposedly prolonged the motor. I see that Amazon no longer handles the attachment but it can be found on ebay. My understanding is the Blade Grinding Attachment is just that. One removes the sharpening cassette that comes on the WS then attaches the Attachment. So, one will have to buy a WS first. I’ve the Attachment pictured with and without the WS, not knowing if this is an advertising gimmick or not, I suggest that you make the vendor explain clearly what they are selling. As for the WS itself I’ve used mine for nearly 10 years for sharpening hatchet, scissors, two sizes of garden shears, knives, X-acto blades, and of course swords, several Windlasses from scratch. The issue that I’ve found is with the guide on some swords, the blades were too thick to fit. I did the job free hand with no problems. I’ve been through several boxes of factory-made belts. The last go around I ordered belts by a third party and found them cheaper with a wider variety of grit. If you go the route of the WS, I suggest the KO edition as it has a wider belt and is more versatile. I will say up front that it will not handle all jobs as well as if some other method is employed. I would prefer not using it on a katana like blade for instance. Having said that, I’d be lost without mine.
PS the edge angle selection is 15-30°. In time you’ll find your preferences.
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ghost
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Post by ghost on Aug 3, 2023 1:17:54 GMT
yes absolutely get the attachment.
it is much easier to hold kitchen knives, longer blades horizontally to grind and is very comforting have a better visual. (think knife tips)
it also is heavier and much less likely to shift around. (if you try and horiz grind without the attachment there are barely any contact points to the table)
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