My knives aren't getting sharp anymore – help?
- This topic has 18 replies, 9 voices, and was last updated 04/10/2016 at 7:41 am by
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It sounds to me like to separate issues:
- The blade itself might need reprofiling. Hard to say without a picture, but sharpening every three days over several months tells me it’s getting too thick behind the edge, so no matter how sharp the edge is, the knife won’t cut well. If you still have access to the freehand stones you mentioned, easiest way to thin it is to lay it flat on a stone, and thin the whole blade. Or you can grind in a lower primary bevel, then sharpen at your normal angle.
- If you’re 200g stone cuts better than your 100g, and assuming your 200g is ‘broke in’, then you might be due for a new 100g stone.
I’m curious, how do you sharpen it every three days? Unless there is damage to the edge, even a dull knife should be able to resharpen with the finer stones… no need to go thru a whole process. Especially the 100g stones… these should only be needed for reprofiling and/or repairing a damaged edge. (Just wondered if that’s what was wearing them out?)
p.s. One way you can tell if a blade needs thinning is to lightly pinch the blade above the shoulder of the edge, then drag your punched fingers over the shoulder… if it feels like you’re going over a bump as it transitions to the edge bevel, it’s most likely to thick above the bevel, and needs thinning.
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The lower the dps, the longer the edge stays sharp due to a decrease in pressure needed to go through an item….
This is an under-appreciated piece of wisdom. We did a test at our shop of two identical Forschner chefs knives, one sharpened at 20° per side and the other at 15° per side. We then used these two knives on everyday tasks, preparing veggies and snacks for the crew, constantly swapping which knife we grabbed and alternating users. The steel on these stamped knives was nothing spectacular and yet the blade sharpened at 15° stood up and retained it’s sharpness much better. I’ll dig around and see if I’ve still got the stats.
Also as Josh and others have shown thinning the primary grind will give an increase in performance. Could be a great opportunity for multiple improvements, good luck!
Agreed – blade thinning seems to be the likeliest place to look. I’d thin the blade, then go for a fairly low edge angle. If you find the edge failing too easily, just add a little micro-bevel, 1° wider and see how it does. You might also experiment a little with the finish, maybe a little toothier than you’ve been doing. If your stones are really well broken in, maybe they’re no longer leaving teeth that are very pronounced, reducing your slicing efficiency. On second thought, maybe the first tweak to try is a toothy edge. This would be very easy to do and test and you would have changed only one variable. Once you see how that does, then maybe tackle thinning and re-profiling. Please let us know how it works out!
-Clay
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Whenever someone says they don’t know why their knives aren’t sharpening right, the first thing I think is that they need a handheld microscope or a very good loupe. You need to see that edge to know what it needs.
I never use my 100/200 grit stones unless I’m doing some serious re-profiling. In fact, I try to never let these coarse stones touch the apex, as they can break out chips of steel along the edge which are really difficult to remove with finer stones. If your 200 feels like it’s cutting faster than your 100, my guess is that your 100 is well broken-in, while the 200 is not. Or cbwx34 is right. You shouldn’t have worn out a set of stones within a few months. Look closely at the stones to see if there are areas where the grit has been completely removed from the platen(s). If so, maybe you’re applying too much force.
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It is really hard to say what’s going on here as there are so many variables…
- Do you use a smooth butcher’s steel while at work all day?
- When you sharpen, do you finish with edge leading or edge trailing passes? How do you verify that there is no wire edge left? (this would fail very quickly)
- What angles are you sharpening at?
- Are you hitting bone when cutting the meat?
What I do for many is reprofile the edge to do the heavy profile work and lower the angle, then they can maintain VERY easily w/ a microbevel in just a few passes when it’s dull. You can do the same thing with something like the Ken Onion Work Sharp.
I am very curious to see pics and hear measurements…
As an example of thinning the primary grind, here is a kitchen knife that could have been turned into a scandi grind or a chopper it was so thick… that pile of ‘stuff’ next to it is the steel removed (I grind under coolant so I was able to capture the steel dust). This would likely drastically help you. You can do this with a harbor freight 1×30 belt sander w/ some practice.
Before Pic:
After pics:
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I use a medium cut butchers steel I sharpened using a circular motion with the stones and finish with edge trailing passes For the wire edge I usually alternate passes on each grit to get rid of the burr (as told by clay in one of his videos) I sharpened at 20 degrees I don’t hit bone, I use another beater knI knife for when I know I’m going to hit bone
Try this: reprofile your edge to 15 dps and take it through 600 grit or so (make sure you have a full burr the entire length on both sides at the 600 grit level). Next move your arms out to 19 dps and get your 800 grit stones, don’t use edge trailing passes, use edge leading alternating passes whisper light for about 15-20 strokes. This should give you a burr free apex with no wire edge that will be sharp and last a while.
When you steel, use only edge leading passes and try to get as close to 19 dps as you can free-handing/eyeballing.
Let me know how this goes.
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I use a medium cut butchers steel …
Just out of curiosity… ever consider using a ceramic rod instead of a butchers steel? I can bring an edge back faster and better with a ceramic vs. a steel; usually only 1-2 passes per side on a ceramic will bring back the edge, and it’s better than a ‘steeled’ edge. I’ve read breaking may be an issue, but DMT, for example, makes an aluminum ceramic rod, that solves this. Just curious.
Josh’s advice is what I’d suggest too.,. should result in a great, long lasting edge.
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Everyone has provided great advice here which is why I love this forum. I would add only one thing. It takes a lot of time to perfect the use of a “Steel” for straightening the perfect edge created by the WickedEdge. As the day grows long, it gets harder to keep that perfect angle. Knowing this, butchers in large meat processing plants have gone to something like a “Mouse Trap Steel/Ergo Steel”. This “Steeling” technology is “Light years” ahead of the traditional butcher’s steel, the “Mousetrap® Steel” has been used for years in meatpacking and poultry processing plants to restore and maintain sharp edges but many different manufacturers are creating them now under different names (It’s amazing how easy the perfect solution gets lost with time).
Maintaining a Wicked sharp edge is critical to these plants as it sounds it is to you. It’s effortless and takes all the angle placement guess work out of the “Steeling” experience. They come in many different materials and sizes and mounting options. Check this video out for a few options and see it at work… https://www.youtube.com/watch?v=dK6IC-0XNTs In my restaurant sharpening exchange program, I provide this as a critical part of my maintenance and sharpening program. I promise, you will see immediate results and this will result in less sharpening, cleaner cuts, and less work. Thin your edge first as everyone else has said…
Food for thought; The Wickededge produces a very finely honed edge. Using a ceramic or a “Shiny silver like” steel would be much better than the typical coarse “butchers steel”. If you use a course steel on a wicked edge’s finely honed knife apex, you basically are taking a step backward. Refer to previous paragraph for the solution.
I have made one other observation. Are you using a stainless steal knife or a high carbon knife? In your application, it has been found that Stainless Steal holds it’s edge and is easier to maintain between sharpening. This information was written by John Juranitch in the Book “The Razor Edge book of Sharpening”- Copy right 1985″ He specialized and acutely studied the processes of the meat processing plants all over the country. I have learned a lot from this book and maybe you will to.
We all are looking for feed back, so please check back with us.
Eddie Kinlen
M1rror Edge Sharpening Service, LLC
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