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Consider a hanging leather strop as a user friendly alternative.

It's flexible, conforms to the cutting edge (especially useful for people who sharpen infrequently), and it won't change the blade geometry so much that you'll have to reprofile their knives each time they bring them over to you (saving time)

The risky part of providing an alternative (like a honing steel) is that you're not there to stop bad technique, or over sharpening.

Even though I sharpen knives for a living, I don't sell customers any sharpening tools, only a leather strop mounted on a rectangular plastic backing. That way, it's much more forgiving to bad technique, and saves me time with reprofiling the next time they visit. (I've repaired too many concave knives to trust customers)

This may be a good place to start

https://slipakniven.com/product/adapter-for-2-wheels-long-version/

I've used my DC-250 since... December last year? It still cuts very well for 360G, but for faster reprofiling, I still use my SG-250 (graded to 220G)

Every 1-2 weeks I clean all my diamond grindstones in my ultrasonic cleaner, then "rinse" them in the ACC-150 solution by mounting it on my T8, then running it through the water trough for a few minutes.

I would recommend getting a combination of SG-250, DC-250, and DF-250. These should cover almost all knives (and scissors) you can throw at it. I chose to use mainly diamond grindstones because I wanted to speed up grit progression by using the same diameter grindstones (and also to sharpen ceramic knives)

Most knives I sharpen with the DF-250 (600G), I barely see the scratch pattern after honing on the LA-220 leather wheel. If you're pursuing a mirror-like finish, then the DE-250 (1200G) would be an economical and practical choice.

I do use my DE-250 (1200G) and SJ-250 (4000G) for commercial chefs (and some customers) who request for it, but that's far and few in between.

I have all 3 diamond grindstones for my sharpening business.

I typically use the DC-250 (360G) to reshape/reprofile blades, and sharpen with the DF-250 (600G). Only when the customer wants a finer edge (and willing to pay more), do I use the DE-250 (1200G)

From personal experience... Going from the DC-250 to DE-250 is going to add a lot of time to your sharpening. Some factors to be considered are hardness of the steel, and what level of sharpness you're trying to achieve.

I spend most of the time at the DC-250, lesser time with the DF-250, and the least time with the DE-250.

So it's definitely a possibility, but the time take  is going to be hella long.

Many thanks for the follow up Nick.

I currently record images of customer knives, before & after, as well as digital microscope images of the before & after.

I don't typically send them out to customers post work, and use them more like a "break glass in case of emergency" type deal... You know, in case I get that unsatisfiable customer.

But I got a good review from the customer, so it all ended up well. But I'm always thinking of how to recreate good results more consistently and predictably in future.

Totally agree with you Nick.

I think a bit of background to this "theory", is that I'm still working on a framework to categorise my sharpening services pricing for my business, as well as streamlining workflows.

Almost all my customer knives have required repairs of different extents, and I was tired of doing these repairs without getting properly paid.

So I developed a framework (that included estimated bevel height) so that I could consistently move customers towards the appropriately priced service tier, to be fairly paid.

So when receiving knives, I measure the behind-edge-thickness, estimate the bevel width, and let them know what the final product will look like. Most of them gauge the quality of service based on the appearance of the knife (strange, I know) I still find it odd how my sharpening business really picked up after I got a bench polisher.

So, for this knife in conversation, I told the customer beforehand that the recommended sharpening angle range (15-20 DPS) would produce a bevel of 1mm width or less, and it would be hardly noticeable. And if she was agreeable with it, then I would proceed with work.

I actively try to avoid getting into disputes with uninformed customers who receive their knives post sharpening, and ask me why almost nothing was done, because they didn't notice any significant difference. (When handing over knives, I typically do a paper cut test in front of them, before they make payment. Using my PT50A test results just goes over their heads, but they can recognise a paper cut test)

So thinking back, my question was more of dealing with customers and what standard of work was deemed "acceptable", in a commercial sharpening context.

Many thanks for the responses.

I'm already done sharpening the chef knife, and the edge meets my standard of sharpness.

I think I was more curious about what kind of "standards" professional sharpeners work towards, especially when adding uninformed customers into the equation.

Regarding the bevel width, it's just my working theory that if the bevel width is too narrow, then the knife would have more difficulty slicing softer food (like meat) because before the bevel can start the cut, the primary bevel would be trying to wedge itself into the food. If the bevel width was too wide, then it becomes more vulnerable to rolling over/folding. So it's just based on observations from customer knives, my own knives, and brand new knives in stores, that I try to work towards a 1-2mm bevel width.

Good point, I asked about how to sharpen, but the focus of the question was not exactly aligned with what I asked.

Part one of question:
Seeking advice on how other Tormek users would sharpen a knife with an extremely thin blade (0.5mm behind edge thickness)

Part two of question:
Would a <1mm secondary bevel width be considered acceptable? (I typically aim for 1-2mm bevel width, in conjunction with the sharpening angle)

This knife is already sharpened at 15 DPS, but the secondary bevel is <1mm wide. So I'm just looking for advice if this is commonly done, or generally considered too narrow.

Just on a hunch, use a marker pen to mark the secondary bevel on your Japanese knife, and try a few light passes. See where the marker has worn off.

I typically sharpen Japanese knives at about 10-12 DPS.

My suspicion is that your sharpening angle of 15 DPS may be a bit too obtuse for the original edge.

A customer recently handed me a few knives for sharpening. Among the 5 knives (all Anolon brand), 3 of them have deep grind marks along the entire length (I'm going to guess it was from a bench grinder)

What I've done so far for the chef knife in question:
- Polished the entire blade to lighten scratches and to reduce the visible impact of previous grinding.

- Reprofiled the blade with the SG-250, and reduced the full bolster's width/length to match the blade heel. (The knife was banana shaped, with two knife bellies on the blade.)

- Sharpened with the DC-250 & DF-250 at 15DPS, honed with LA-220.

My question:
How would you sharpen a chef knife with a behind edge thickness of approx. 0.5mm? (No error, it's 0.5mm) I've tried and the secondary bevel is approx. 0.8-0.9mm. Would you consider a secondary bevel so narrow to be "complete" or "sharpened"?

Attached image is before sharpening.

[Me:]

My latest encounter with customer logic:

Me: Your knife tip is broken, do you want to repair that? There's an additional cost to grind down that section.
Customer: No no, there's no need. I don't use the knife tip.
Me: *thinks about knife constantly getting caught on cutting board* Okay

Me: Your cleaver has a lot of rust on it, do you want to remove it?... Or do you have any polish at home to remove it on your own?
Customer: Hmm... mmm... The rust is fine, no need for removal.
Me: *thinks about all the bacteria and food getting stuck in the blade, and rust flaking off onto food* Okay

Customer: I tried sharpening the cleaver on my own, but it couldn't pass the paper cut test.
Me: Yeah... It's a meat cleaver. It's got a very wide edge angle and made of softer steel because it's designed for breaking and splitting food apart, like a tiny axe. It won't really pass your "paper cut test" because the angle is really wide... What have you been using it for?
Customer: It was given to me brand new, unused. I haven't used it yet.
Me: *thinks about repairing yet another botched sharpening* Okay

Customer: After your sharpening, my knife looks very different, seems smaller!
Me: Yeah, knife sharpening works by carefully removing metal to create a sharp edge. All knives get smaller during sharpening, never bigger.
Customer: Ah yes, it makes sense.

Edge retention is still something that is somewhat of a mystery to me.  I have tried 600 grit and very little honing to highly polished.  Neither seem to be superior in terms of edge retention.  That is, retaining a 70 edge on the BESS.
After use, all steels I have sharpened lose that super sharpness in the first couple uses.  Some steels jump to a 140, some to 240 on everything but the softest foods.
They all seem to lose that eye popping sharpness very quickly.
I only have my tests to gauge this on.  I haven't seen any tests for real world usage to measure how fast the edge degrades.  I suppose CARTA tests do show the degradation but usually they demonstrate how long the usable edge lasts, not how long they stay ultra sharp.
Once again, how sharp you need/want to keep your tools/knife is very personal.  I had a carpenter look at a chisel sharpened to 90 like it was meh...

One thing I discovered during the course of my knife sharpening business, is how some customers reject modern sharpening methods (like my Tormek T8) to validate the methods that they've been using for the longest time as still "the best".

So the carpenter treating your 90 BESS sharpening as meh, may very well have nothing to do with your processes & results, but more to do with him trying to validate what he's always been doing as still "the best". A real life example, is how a local butcher turned down a free sharpening from me because he only believed in his own sharpening methods. His knife had only been thinned, no secondary bevel left, and the mystery whetstone he was using was like a misshaped bar of soap.

Another example was how a restaurant owner who was proud of learning how to sharpen knives since he was 14 (he was in his 50s when we spoke) but couldn't define what "high carbon steel" was, had no concept of knife geometry, as well as knife anatomy. The biggest indicator to me was when I offered to do a sharpness test on any of his knives for free (using my PT50A), and he immediately refused. That told me that he was rejecting me not because my methods and case studies sucked, but he was more worried that I would make his knives actually sharper, and totally invalidate everything he thought he knew.

Looking at your images, the bevel looks a bit rough for a blade that went through the SJ grindstone.

It seems like the gap between your grindstone grit size may be a bit wide. The last knife I sharpened was an Ikea 365+ knife (soft X50CrMov15 steel) My second last grindstone was the DE-250 (1200G) followed by the SJ-250 (4000G), then honed on the LA-220. I tested on my PT50A and got about 108.

My workflow has the knife go through 360G, 600G, 1200G, and sometimes 4000G. I have no insight into your CBN grindstone, but from what you wrote, it seems like you spent more time on the much higher grit (honing). I think it would help a lot if you used a 1000+ grit grindstone somewhere in your workflow.

Interestingly I find most folks seem to care less about their knives.  I charge about double what most knife sharpeners in my area charge.  My grinding isn't perfect, but I try to make them perfect every time.  That's why I charge more, I sharpen every knife like they are mine.  It takes time.
(And only you and I know they're not perfect)

I recently reviewed my pricing, and I created a framework where I would try to find a balance of two main factors.

The first factor was basing the average time spent per knife on an hourly rate, and how many knives I can sharpen within the work day.

The second factor was my pricing compared as a percentage of the cost of knives purchased by my target market. (People who buy German & Japanese knives, middle to upper range)

So now, whenever I get a customer who's holding their dull Japanese knife they had dropped $300-$400 on and complaining that my services are expensive, I ask them "Expensive as compared to?... It's either $40 to restore your knife, including polishing the blade and oiling the handle, or dropping a few hundred dollars for a new one"

The lights usually come on in their minds and they see the comparative difference.

My philosophy is that I wasn't involved in trashing the knife, so I'm not going to share in the cost of fixing it.

I think it's quite common for Tormek T-8 users on this forum to sharpen with the grindstone spinning towards the knife edge (called edge leading) I run my own sharpening business, and I sharpen almost all customer knives edge leading as well.

The grindstone spins only in one direction, and the way the T-8 drive system is designed, I don't think it'll spin in the opposite direction consistently even if you cracked open the machine and reversed the polarity of the electric motor.

Don't sweat the diamond grindstone getting damaged with edge leading sharpening. The diamonds are electroplated onto the steel hub, and is pretty robust (think of it as "gluing" the diamond dust with another metal... Tormek uses nickel I think)

I do sometimes sharpen edge trailing (grindstone spinning away from knife edge) when I've ground a distorted knife edge flat, and have a square edge where the cutting edge was. I'm still not too concerned with the knife edge damaging my diamond grindstone, but more cautious about the edge catching onto the grindstone, and the entire knife gets thrown away from me.

If you're concerned with damaging the grindstone with edge leading sharpening, I propose starting with light pressure and a small knife (3-4 inch blade) to get a feel of the grinding process. 600 grit against a blade will give some "pushback", but still waay easier to control than a dull blade on the 360 grit diamond grindstone.