Sharpening

D

daverave999

Joined
Jan 16, 2003
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Prompted by the primary/secondary bevel thread started by patrickb and not wanting to jump in with my sharpening failures I thought I'd start a new one!

I'm needing a touch of help with my sharpening if anyone would care to chime in please?

I sharpen one edge until a burr forms. Should I now repeat this on the other side, or should I just remove the burr I've formed? Or do I create the microbevel at this point?

Usually I try to remove the burr at an increased angle on the other side. My knives get sharp, but nowhere near as sharp as they came in the box.

Any suggestions folks?

[EDIT] Is it sharpening season or what!? How many threads on the first page... :eek:
 
try one alternate stroke for each side... irrespective of whether or not you raise a burr...

That makes sure that your sharpening is going evenly.
 
It depends on how dull your knife is to start......If you constantly sharpen one side first, you will end up with a wider bevel on one side than the other since you are removing more material from one side. So I usually go about 10 strokes on one side, check for a burr, then 10 on the other...until a burr starts to form. Once you have the start of a burr, keep going on the current side until you have a complete burr the entire length of the edge, flip and repeat. (This establishes that you have sharpened all the way to the edge on both sides of the blade)

Now, its IMPORTANT to alternate sides on each stroke as you grind off the burr.....I start by a couple of light strokes at the current grit, then switch to a finer stone...I personally will take this all the way down to a mirror finish before changing my bevel for my final edge. But that is mostly for asthetics, once you have that complete burr on both sides, you can then change the bevel for the final edge.

edit..btw, you didn't mention what you were using to sharpen with, it would help if we knew what you were using.
 
I'm using a red DMT hone on a SOG Flash 1. I have been completely unable to remove hair from my arms using a knife I have sharpened so far, not that this is the be all and end all, but they don't feel super sharp yet. Thanks for comments so far folks.

[EDIT]
Dcon67 said:
So I usually go about 10 strokes on one side, check for a burr, then 10 on the other...until a burr starts to form. Once you have the start of a burr, keep going on the current side until you have a complete burr the entire length of the edge, flip and repeat. (This establishes that you have sharpened all the way to the edge on both sides of the blade)
Click to expand...
Sorry, do you mean stroke one side until a burr forms then do the other side OR keep doing both sides until a burr forms, then carry on on the side you noticed it starting to form on?
 
daverave999 said:
Sorry, do you mean stroke one side until a burr forms then do the other side OR keep doing both sides until a burr forms, then carry on on the side you noticed it starting to form on?
Click to expand...

On a dull knife where you will have to do a fair amount of grinding to produce a burr, I alternate sides after each 10 strokes (10 strokes on one side, then 10 on the other, this will keep the grinds even and the edge centered). Then once you feel a the start of a burr, continue on just that one side until you have a complete burr before flipping and grinding the other side until there is also a complete burr. Then all you have to do is grind off the burr :D , which is where increasing the angle and making that second bevel(raising the spine a tad higher from the stone) will help immensely....especially freehand. Don't forget to alternate every stroke once you are doing this....All you are trying to do is grind off the burr, and each stroke the burr flips to the other side, which is why you must alternate.
 
When you use the one-side-at-a-time method you do not need to remove the burr until you have honed both sides (approximately evenly). Sharpen one side at a nice low angle until you feel the burr on the other side in a few areas of the edge. You don't want to raise a burr along the whole edge since that removes too much material. Switch sides and work the opposite side at the same angle until you get a burr along the full length of the edge. Now you tip the spine of your blade up to about twice your finish honing angle (I assume you have been working at 15-degrees per side or less up to this point and you intend to finish with a few strokes at 20-degrees per side. Elevate your blade angle to around 40 or 45 degrees) and do a few light edge-forwards deburring strokes alternating from side to side. Since you have been using the one-side-at-a-time method you will have a very large burr to remove. You will need to feel for the burr to go away and do a few extra strokes to be sure you really got rid of the burr.

Now go back and hone at your 15-degrees or whatever alternating sides for about as many strokes as you did for your deburring. Now elevate your angle slightly and do about the same number of strokes very lightly at around 20-degrees. You may need to do a few more and a little stropping on leather may help. The reason that you are not getting a good shaving edge is that you are using too coarse a hone for that type of finish. Below is a description from DMT of the "red" grit (that you are using) and "green" grit which is finer. I would finish with a fine ceramic hone if I wanted a shaving edge. The "red" finish is practically better in most cases since it leaves a little microserration for better slicing.

Fine– Restores to a fine edge any knife or tool that is slightly dull. Many of our customers consider the fine grit to be a medium/all purpose sharpener. Professional Chefs and gourmet cooks prefer using our fine grit models. For woodworkers and sportsman who are stepping through the grits, it’s the edge refinement step done before micro beveling and polishing. Color code: fine (25 micron, 600 mesh) "red".

Extra Fine- Refines and polishes the sharp edge to razor sharp perfection. If you are new to sharpening or if you do not need your knife or tool edge to be as sharp as absolutely possible, this grit is not recommended. But if it’s not sharp until it’s sharp enough for you, this is the grit you are looking for! Color code: extra fine (9 micron, 1200 mesh) models "green".
 
Aha! Not quite shaving sharp but definitely better than previous.
THANKS!
I think I may have worn my hone out though, through previous over-exuberance. Is pressing too hard likely to damage a diamond hone?

[EDIT] It's been a case of cross posting Jeff due to a combination of sharpening and typing. How sharp is the sharpness attainable with 600 grit? What kind of performance should I expect from my edge? Maybe this is the ultimate unanswerable question, but how do I test how sharp it is?
 
pressing makes it harder to sharpen both sides equally and causes undue fatigue. I use only a small amount of pressure over the weight of the knife, or just the weight of the knife.
 
Right, I have definitely overdone it with the pressure then.

Slicing a firm plum was effortless (with a sawing stroke under the weight of the knife) if this is anything to go by...
 
Great advise ^^^.
I would only add the following.
There comes a point in the sharpening process when you can raise a burr down the whole length of the blade, and flop this burr from side to side with alternating strokes of your sharpening device.

When you can do this, you have arrived and have only a couple of tasks left.

Burr removal. Use a strop or continue with your sharpening device, but at a slightly greater angle and LIGHT AS A FEATHER. You just want to kiss the edge and cut off the burr NOT flop it to the other side again. One pass only. then look and feel for the burr. Same thing with a strop. Very light but this time try and duplicate the angle used to sharpen. Just a few gentle swipes to wards you ,spine first ,then the other side.
 
For burr-removal, I prefer a fine stone such as the Spyderco White.

Using a strop for burr-removal is very likely to produce a 'sharpened burr' - which collapses with any significant cutting pressure.

In the final stages, stropping AFTER burr-removal, I test the full edge by slowly slicing through newsprint over the full edge - looking for equal sharpness over the full edge. If acceptable, that is followed by 3 or 4 heavy-pressure slicing strokes into hardwood or plastic. Then repeat the newsprint test to test for residual burr. If no burr, the newsprint-slice test should be just as smooth and quiet as before. Any dull areas after the harwood/plastic slicing strokes are probably due to collapsed burr.
 
Slicing a firm plum is no measure of sharpness. The real test is cutting a very ripe and soft plum or tomato. If you leave a 600-grit finish on your edge it should slice through the fruit skin with very light pressure and a drawing stroke. This should allow getting thin slices even of a soft tomato.
 
I've beat my DMT stones half to death, and haven't worn one out yet. When they don't seem to cut very well anymore, I wash them off really well with water, and they cut just like new again. I have read that they don't need any lubricant, but if I use water, I have better luck (not so much for "lubrication, I think, as for washing the steel particles away).
:)
 
I've kind of worn out a DMT red stone. It's smooth as glass, and no amount of cleaning will bring it back. I think it's down to the nickel backing. :(
 
tomato.jpg


The tomato test was almost as successful as I had hoped it would be. I think it was overripe though, kind of wrinkly.

After a bit of a wash, the hone did seem to improve, although the far end away from the keyring is a bit glass-like.

I have to say a massive thank you to everyone! I am very pleased with the results :D
 
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