Higher grits makes the edge duller !?

awestib

awestib

Joined
Dec 29, 2008
Messages
1,647
Hi Folks:
I have been practicing freehand sharpening for the last months once in a while, never really have time to spend more than 1/2 hour or so but anyway. I am getting better at it, still end product is barely shaving.
Here is my question: I start out with a coarse diamond stone and try to refine the factory bevel for instance. There already I am not able to follow the bevel accurately. I just can't get that "feeling" of being on the bevel (as described by knifenut etc.). I tried different techniques, forth and back strokes, just edge leading stroke only etc. I continue until I have a burr all along and flip over. After the diamond I think I have a decent edge, again not shaving but not bad.
But here is the problem. The more stones I use after this (1000, 3000 waterstones), the more room for error is there I believe. I am not better in following the bevel just because I have a finer stone, so I end up making the edge duller after all. Stropping at the end helps a bit but still.

Any suggestions? Shall I just strop after the coarse diamond stone? Will I ever be able to get a polished edge that whittles hair? I don't want to use any gadgets!

Thanks!
 
After the diamond I think I have a decent edge, again not shaving but not bad.
Click to expand...
Practice.

You should be able to shave arm hair (at least somewhat) after sharpening on the coarsest abrasive you have. I am not sure what you have but to give you an idea, you should be able to use the DMT extra extra coarse to sharpen to the point of shaving quite well.

If you can not pop off at least a few hairs, you have not properly joined the bevels and I would not recommend proceeding to finer stones.

Sharpening free hand takes time to develop. Be patient and establish a good foundation of solid form. Establishing good foundation of skills is the fastest way to become VERY good at sharpening...but "fastest" does not always mean days or even weeks...some people take longer than others.
 
Are you getting a burr at your finer grit? You don't have to follow the angle perfectly just make sure you don't keep on raising the spine of the knife higher and higher.
 
When establishing a new bevel it's useful to use an angle guide. I have an ancient Buck Honemaster (no longer made, alas) which clamps to the back of the blade, but there are others available.
 
I use a DMT extra course/coarse duosharp. Since I will have quite a burr/wired edge with this stone, how do I know that the sharpness is not from that?
 
I can get a very nice edge from a coarse diamond stone, but the waterstones don't work for me at all, so no advice on those from this quarter. Good advice in the above responses, I'd add that you should be learning on a cheap knife. Also, use a Sharpie religiously until you get the feel of following the bevel. Diamond stones, especially new ones, tend to cut the metal so well that you'll have less feedback then you might get from a different media - the difference in feel from being on the bevel, to being on the shoulder or too deep into the edge is not that great. Once they break in that'll improve, and a splash of water on the stone helps too. "Don't trash a good knife learning" says the ghost of several expensive Benchmade folders I absolutely destroyed before getting proficient. I still get annoyed with myself every time I think about it.

HH
 
I'll add a suggestion to the good advice already posted earlier.

I found, that while trying to develop the 'feel' for maintaining flush contact on the bevel, it's safer to start with a higher grit (Fine/EF/EEF), and practice on a knife with an edge & bevel that's already in pretty good shape (such as the factory bevel on a new, inexpensive knife that you already know cuts fairly well). Use a good magnifier and BRIGHT light to frequently inspect the edge as you go. Take it very slow and easy. The goal with this method is to see if you can refine that factory edge to better-than-new, while at the same time, minimizing the damage done if your technique is not quite perfect. Trying to learn the technique with a coarse or XC stone can be doubly frustrating if you remove WAY TOO MUCH metal while trying to learn it. You're then faced with the task of repairing that edge, before you're comfortable with the process. Once you know you can improve the factory edge, using a finer grit stone with good/very good angle & pressure control, then that's the right time to take a shot at the coarser hones, on a knife that needs 'em. And approach it the same way, using the magnifier and bright light to inspect frequently as you work. That will give you an earlier indication, if your technique begins to drift a little bit.
 
You do know about the sharpie trick right?

That will show you where your stroke is failing (and if it is failing) to make good contact. It will also show you how consistent you are.

Another method I have used to tutor people with is to get a sheet of glass and lay the knife stationary on it (you are not stroking or moving the edge off of a single point on the glass) and rock the spine up and down and "feel" when the bevel engages flat on the glass. Do this on about 5 to 10 spots on the edge to gain understanding of how the handle needs to pitch and turn when you actually stroke the stone.
 
David, do you use forth and back strokes or rather just edge leading strokes, lift up and back and again? I guess if we are out for feeling the edge flush on the stone, forth and back might be better?
 
awestib said:
David, do you use forth and back strokes or rather just edge leading strokes, lift up and back and again? I guess if we are out for feeling the edge flush on the stone, forth and back might be better?
Click to expand...

Back & forth MIGHT be better. That's mostly a preference thing. Or a 'circular' (or elliptical) motion might serve the same purpose. The main goal is to find a method or stroke that maintains flush bevel contact in the manner that's most comfortable to you. If completely re-grinding a new bevel on an edge, I've found a circular/elliptical motion to be pretty effective. It does seem to be easier to keep the bevel flush, and it also works faster in removing metal. Once the new bevel is established, I usually finish with edge-leading only (on stones/hard hones). Finishing that way puts the grind marks more perpendicular to the blade edge, which I think enhances cutting. BUT, once again, that's my preference. I'd encourage you to experiment with various motions. You might find that a certain motion works best for some knives, and something different for others. With that in mind, the circular/elliptical motion is much better suited to small (pocket) hones, when a long, sweeping motion from heel-to-tip wouldn't be possible. I often like to use some small 'credit card' diamond hones (DMT) to put new bevels on pocket knives, and the elliptical motion works well in this capacity.
 
I find back and forth or circular strokes are only good (for me) for lots of stock removal and always seem to result in greater deviation from a true V edge (i.e. the result is a greater degree of convex). I use these motions for the early stages of stock removal (like when I take a bevel down by 5 or more degrees per side, or when I want to convex a blade).

For routine sharpening I use edge leading exclusively on hard media (i.e. DMT plates, or ceramics) and edge trailing strokes exclusively on soft media (wet/dry sandpaper, or strops)...and, yes, I believe that 100% of the users of soft media as I have described it use trailing strokes exclusively;)

For hard media, I think most people would say it is a matter of preference (leading, trailing, back and forth, or circular). That is whatever works best for the individual. For a VERY small few, there are claims that trailing strokes produce different results...but this is a debated point amongst the truly hardcore "testers"...I am not part of that group...I simply do what works best for my abilities. And truth be told, I would bet that 99% of veteran sharpeners do what they do simply because it seems to work for them and their subjective results are all they need (i.e. if a guy can put an edge on that will survive only a few cuts before it shows signs of degradation...why try and squeeze more out of his technique if the steel can not support it?).

Hope that helps.

In summary, do what gives YOU the best results.
 
You must log in or register to reply here.
Back
Top