Best free hand sharpening method?

M

MikeMade™

Joined
Nov 17, 2005
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I've been fooling around with freehand sharpening for a while now and I just wanted some new ideas on how to improve my method. Im using Spyderco ceramic stones: the medium, fine, and ultra fine. My sharpening angle is about 18 degrees. Once the burr is formed when is the best time to do a burr removal step? Should it be done on the coarser stone or once I am done honing on the ultra-fine? The burr removal method i have been using is once the blade is honed on the ultra fine, I increase the angle to 40 degrees for 5 strokes on each side, then go back to 18 degrees for 5 strokes on each side, then finish off with 20 degrees. I have also been having a little bit of trouble with wire edges developing. The blade steels I am working with right now are S30V, 154CM, and M2. Any feedback would be greatly appreciated!
 
I remove the burr at each grit level. After the coarse level I really don't even want to get a burr. I use a simular method to remove a burr as you do.
 
you might want to try sharpening 1 stroke per side through all grits. this combined with a marker too see when you have completely gone to the end of your bevel. ive noticed much less of a burr using this method.
 
For some steels, a difference of 2 degrees between main bevel and micro-bevel will make it very difficult to cut the burr - the burr just flops back and forth. ATS34 is an example - difficult to cut a large burr even with a 5 degree bevel angle difference.

If a final edge/micro bevel of 40 degrees included is your goal, I would thus suggest 15 degree main bevels with 20 degree micro-bevels. The differences between your 18/20 bevels and suggested 15/20 bevels:
- Burr-cutting should be easier.
- Edge-strength should be equal.
- Slightly improved slicing, due to narrower relief grind angle.

Hope this helps!
 
Gud4u I think he is doing the burr removal at 40 degrees per side then moving back down to 18 degrees per side. I'd guess he isn't raiseing a burr at this time, then he is putting on his micro /cutting edge at 20 degrees. I'm not real sure what his trouble developing a wire edge means. A Burr? I'd say if you want to get a burr do it with the coarsest hone. That could take some time with the Spyderco medium.
 
MikeMade™;4020043 said:
I have also been having a little bit of trouble with wire edges developing.
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The UF is not abrasive enough to use for burr removal, the edge should be very sharp at each grit. It doesn't need to be optimally sharp but the burr should at least be beyond the visible. If you are regrinding the edge often it is weakened by the heavy force on the stone, similar for sharpening really well used blades. I have started cutting the blade into the stone before sharpening to grind into that weakened metal and remove it. This has made a major influence on minimizing burr formation.

After the first shaping step look at the edge under magnification, even 10X will do. The edge should have formed clean, yes it will be very coarse, but it should be even in appearance, if there is a lot of random jaggedness and especially if it is bent or squared in sections there there is still too much weakened metal on the edge. Cut that off by cutting light into the stone and resharpen at the lower grit. If you leave this junk on the edge it will take forever to remove with the finer stones.

Once the edge is quality steel then a burr will generally only form for two reasons, the steel is deforming or fracturing. Fracturing is usually only an issue with some very hard japanese blades when used on ceramic rods. To minimize deformation you want to keep the force at the minimum required for significant abrasion and once the edge is formed you also want to keep the travel on the blade to a minimum becuase anything beyond what is necessary to cut off the burr on one side just forms it on the other side. So you use the most aggressive stones you can afford, keep them clean, and flat if necessary, and once the edge has been formed you use light pressure and alternature passes with just a bare minimal of travel down the stone.

I noted there were only two ways a burr would form, there are actually a few more but they are either rare or you can't do anything about them. For example if you take D2 down to a very acute edge and try to polish it the edge will just break apart because it is too coarse for that angle/polish. There are also some very high vanadium steels which people have reported having problems sharpening on anything but diamonds. 154CM is also one of the most difficult steels to sharpen consistently because the carbides are very large and aggregated and thus you can get irregular behavior along the edge where you hit patches which are low in carbide and the edge forms very fine and other patches which are high in carbide and will not.

-Cliff
 
You might want to focus more on M2 as it should be easier to get really sharp, though I assume this is on some production knife at 60/62 HRC.

-Cliff
 
To echo one of Cliff's comments, get a 10X loupe - take a look at your edge through this thing and it takes a lot of mystery out of sharpening. You can see any burrs, and also verify that you have sharpened (or developed a burr) along the entire edge (particularly when you are thinning the edge).
 
Cliff,

The burr removal step must use the minium of forward travel possible while using a side-to-side scraping motion? I've been using a spyderco fine stone, is this to fine or should i be using a spyderco medium stone?

I had a kitchen knife that refused to give up a burr. I did two light swipes into a 1200 grit waterstone and resharpened. After removing the burr I had a knife that would push cut copy paper @ 3/4 inch and easily slice newspaper @ 2 inches. While this isn't "super sharp" for this forum, it was a level I've been previously unable to attain.

Any chance you could post a video of your burr removal step? I can host the video if space/bandwidth is a problem.

Thanks
 
You do not need to form a burr to geta a knife sharp, if don't form it you don't have to chase it. I will put my blade up against anyones for sharpness and edge holding and I never form a burr.
 
leon.pugh said:
You do not need to form a burr to geta a knife sharp ...
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This is generally used as a introduction to sharpening as a means to let people know when they have finished the shaping stage. Generally if you are willing to examine the edge a bit more critically you don't try to create a significant burr at all, even with the most coarse grit used. However there are also large differences among steels. The very hard and fine grain/carbide knives I own for example won't burr significantly in general, however even with a lot of care, the soft and coarse stainless will form a visible burr very easily. You can sharpen without forming a burr if you never form the apex to a point outside of the finishing grit, but that is really time consuming and unless the edge is all quality steel it would be a waste of time anyway.

-Cliff
 
MikeMade™;4020043 said:
I've been fooling around with freehand sharpening for a while now

My sharpening angle is about 18 degrees.

I increase the angle to 40 degrees for 5 strokes on each side, then go back to 18 degrees for 5 strokes on each side, then finish off with 20 degrees.
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You can tell the diffrence between 18 and 20 degrees, sharpening freehanded :eek: :confused: :eek:
 
Hawkings said:
You can tell the diffrence between 18 and 20 degrees, sharpening freehanded
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That angle difference is about a 1 mm height difference in the spine off of the stone. For a chemist that is a really coarse visual estimate. Most carpenters can actually judge thickness to that kind of tolerance and machinists even more so. I don't think I could, I would expect any freehand I did to vary by about that amount of more unless the knife was self-jigged.

aberg said:
What is the approximate minimum angle that D2 can Handle?
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For light slicing I have taken it down to basically full flat, so about five degrees per side and it will take and retain a high slicing aggression. To take and keep a very high polish it is over 20 degrees per side according to Landes as D2 has an extremely coarse carbide structure and thus degrades quickly unless the edge is obtuse enough to hold these 50+ micron carbides in place. Of course the entire edge doesn't need to be at that angle, just a secondary bevel. There was an informative thread on this awhile ago :

http://www.bladeforums.com/forums/showthread.php?t=392430

-Cliff
 
Cliff Stamp said:
I don't think I could, I would expect any freehand I did to vary by about that amount of more unless the knife was self-jigged.

-Cliff
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yup, surprising coming from you, a difference around 1 or 2 degrees.
 
donny b said:
you might want to try sharpening 1 stroke per side through all grits. this combined with a marker too see when you have completely gone to the end of your bevel. ive noticed much less of a burr using this method.
Click to expand...


Donny, in my experience the marker gives you an indication that you are close to taking the newly-sharpened bevel all the way to the very edge. But the marker will disappear before you get to the end. In other words, the only way to know that the new bevel has made it to the very edge, along the entire edge length, is to raise the burr. Any other way, and I usually end up with sharp spots and not-as-sharp spots. I'd rather raise a small burr and then get rid of it.
 
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