Coarseness/Grit for Regular Edge Maintenance

sailfish

sailfish

Joined
Jan 1, 2019
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I'm looking to make the move into freehand sharpening. With that said, I'm considering one of the Spyderco ceramic bench stones. From what I can gather, the coarseness of the medium stone is comparable to that of 600 grit, and the fine to that of 1200. My question mainly comes down to which is more ideal for touching up a regularly used knife about once a week, sometimes a little sooner, sometimes a little longer. My blades generally don't get all the way to truly dull, but sometimes a day with a good bit of ceiling tile or insulation and S35VN comes along and puts my knife on the bench until I sharpen it.

The majority of my knives are in fact S35VN, some softer like 1095 and some harder like 20CV or K390. I'm okay with spending a few minutes touching up if I have to, and want to be able to take off just enough metal to pop hairs again without taking off too much and unnecessarily reducing service life. I've read that the medium stone is more of a sharpener whereas the fine is more of a "finisher"? I like the idea of getting down to business faster with the medium grit so long as it doesn't overdo it but I'd like to hear the opinion of those more experienced with sharpening than I am. Thanks.
 
the only time i use anything below a 1200 grit is when I have to repair a chip or broken tip. For normal maintenance I will use a leather strop, spyderco (ultra-ultra fine) ceramic rod and maybe my 1200/2400 grit dmt plates if its severely dulled. Anything lower than that is going to remove a lot more steel than necessary
 
My Spyderco medium is not particularly coarse, and takes off a minimal amount of metal. I'd be amazed if you could ever make a knife unserviceable with it over many, many years.
 
buckmaster96 said:
the only time i use anything below a 1200 grit is when I have to repair a chip or broken tip. For normal maintenance I will use a leather strop, spyderco (ultra-ultra fine) ceramic rod and maybe my 1200/2400 grit dmt plates if its severely dulled. Anything lower than that is going to remove a lot more steel than necessary
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I strop at least every couple of days, often daily, but still usually need to touch the stone every week. What kind of steels are you using and what kind of materials are you cutting and how frequent? And how often do you go to the rods?
 
UncleBoots said:
My Spyderco medium is not particularly coarse, and takes off a minimal amount of metal. I'd be amazed if you could ever make a knife unserviceable with it over many, many years.
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Do you use it as a general sharpener/maintainer or something more specialized?
 
The only Spyderco stone I would buy is the UF. Sintered Ceramic stones are slow grinding and work best as a finishing tool.

Being worried about taking off too much metal should be the least of your concern, judgement of removed material is actually pretty easy to follow as long as you are inspecting your edge closely after every handful of passes. Aimlessly grinding on the stone is what leads to unwanted material removal.

You have a fair amount of high alloy steels so I would recommend Diamond plates, personal favorite is the Ultra Sharp 300/1200 combo plate. Little gritty at first but fast (so your grinding stays accurate) and if you have an UF ceramic you have a pretty sweet two stone set that can handle most any issue. Higher alloy steels will perform much better in most cases with a coarser edge so the 300 followed by the UF ceramic is often what I use for my EDC blades. Easier to maintain over time too as a coarse edge strops back to sharp easier and many more times than a more highly refined edge.

Edges will need to be reset from time to time, factory edges fixed of their high and low spots and broken tips repaired. Having the tools to properly handle the job not only makes the task easier but allows you to be confident that the sharpening will not be a challenge.

FYI, Spyderco ceramics if rated like waterstones would go... 1500, 4000, 8000+
 
Jason B. said:
The only Spyderco stone I would buy is the UF. Sintered Ceramic stones are slow grinding and work best as a finishing tool.

Being worried about taking off too much metal should be the least of your concern, judgement of removed material is actually pretty easy to follow as long as you are inspecting your edge closely after every handful of passes. Aimlessly grinding on the stone is what leads to unwanted material removal.

You have a fair amount of high alloy steels so I would recommend Diamond plates, personal favorite is the Ultra Sharp 300/1200 combo plate. Little gritty at first but fast (so your grinding stays accurate) and if you have an UF ceramic you have a pretty sweet two stone set that can handle most any issue. Higher alloy steels will perform much better in most cases with a coarser edge so the 300 followed by the UF ceramic is often what I use for my EDC blades. Easier to maintain over time too as a coarse edge strops back to sharp easier and many more times than a more highly refined edge.

Edges will need to be reset from time to time, factory edges fixed of their high and low spots and broken tips repaired. Having the tools to properly handle the job not only makes the task easier but allows you to be confident that the sharpening will not be a challenge.

FYI, Spyderco ceramics if rated like waterstones would go... 1500, 4000, 8000+
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sailfish said:
I strop at least every couple of days, often daily, but still usually need to touch the stone every week. What kind of steels are you using and what kind of materials are you cutting and how frequent? And how often do you go to the rods?
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Most of what I cut is cardboard, paper and plastic bags and my edcs are all in steels like m390, maxamet, cpm m4 and the like so I strop once or so a month and even then it doesn't take much. Jason's post mirrors my thoughts almost exactly but. If you can swing it, get a course (300), 600, 1200 and the dmt eef which I belive is something like 8k grit. Even the last stone cuts WAY quicker than any ceramic I've used and it will work on any steels you can find.
 
The Spyderco ceramics seem to act much finer than you'd expect, and cut very slowly. I like something around a 1000 grit stone for normal edge maintenance, one that cuts reasonably fast. Diamond for steels with higher vanadium, usually a splash and go water stone for lower alloy steels. Those are my preferences, anyway.
 
Jason B. said:
The only Spyderco stone I would buy is the UF. Sintered Ceramic stones are slow grinding and work best as a finishing tool.

Being worried about taking off too much metal should be the least of your concern, judgement of removed material is actually pretty easy to follow as long as you are inspecting your edge closely after every handful of passes. Aimlessly grinding on the stone is what leads to unwanted material removal.

You have a fair amount of high alloy steels so I would recommend Diamond plates, personal favorite is the Ultra Sharp 300/1200 combo plate. Little gritty at first but fast (so your grinding stays accurate) and if you have an UF ceramic you have a pretty sweet two stone set that can handle most any issue. Higher alloy steels will perform much better in most cases with a coarser edge so the 300 followed by the UF ceramic is often what I use for my EDC blades. Easier to maintain over time too as a coarse edge strops back to sharp easier and many more times than a more highly refined edge.

Edges will need to be reset from time to time, factory edges fixed of their high and low spots and broken tips repaired. Having the tools to properly handle the job not only makes the task easier but allows you to be confident that the sharpening will not be a challenge.

FYI, Spyderco ceramics if rated like waterstones would go... 1500, 4000, 8000+
Click to expand...
buckmaster96 said:
Most of what I cut is cardboard, paper and plastic bags and my edcs are all in steels like m390, maxamet, cpm m4 and the like so I strop once or so a month and even then it doesn't take much. Jason's post mirrors my thoughts almost exactly but. If you can swing it, get a course (300), 600, 1200 and the dmt eef which I belive is something like 8k grit. Even the last stone cuts WAY quicker than any ceramic I've used and it will work on any steels you can find.
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The idea of diamonds concerns me in a way. Mostly because of how quickly I was able repair a broken tanto tip with the Spyderco Sharpmaker diamond rods. That's not too course for regular touchups?
 
The speed should not concern you, it helps you stay consistent and spend less time making mistakes. The speed is also a moot point, It might cut faster on softer steels but in my experience there is not that much difference. If comparing diamond to sintered ceramic then yes the speed is very different but the same can be said for about anything you compare to sintered ceramic. Also, on something like 1095 a waterstone would be faster than a diamond so it must be understood that not everything is equal.

With steels like S35VN and 20cv and k390 diamonds are a must as the alloy elements in the steel matrix are harder than lesser abrasives like aluminum oxide and silicon carbide. In sharpening, the hardest object always wins and you never want the hardest object to be your knife. I often stop at 300 grit on many of my high alloy steels because the carbide rich steels love a good coarse edge. Not only does it last longer but as the edge degrades it helps it stay sharp longer. You may have noticed that high alloy steels tend to loose their hair popping sharpness quickly in favor of a rough "utility edge" that is almost shaving sharp but cuts forever. This is the MO of high alloy steels and to take advantage of their carbide rich matrix for maximum edge retention I try to stay below 600 grit and use diamond whenever possible as it provides the sharpest edge on such steels.
 
I use a comb9nation of 600 and 1200 grit sandpaper we use at work for some finishing processes.

it works pretty well.

600 gets rid of the chips and rolls
1200 finishes it off nicely.

I'm happy with that.
 
I'd call the fine more of a "polisher" but yeah, it's a utility finishing stone.
I'm not a knife maker and so my standards may be different, but I regularly take knives from shaving to won't cut paper in a week. I can get a shaving edge with a 600grit, but a single 400/1000 combination diamond stone is what I've shifted to after years of messing around with a giant tub of waterstones. I go for a "working edge" as opposed to an immaculate, perfect, polished edge; if I can cut a wavy line through newspaper with no tears, that's good enough for me.
Bench chisels, handplanes, marking knives, and other precision woodworking tools are a different story, they are fastidiously maintained and I can generally see my reflection in them. They go from 1000 to 6000, and get reground and reprofiled if they're really knocked around.
 
sailfish said:
I strop at least every couple of days, often daily, but still usually need to touch the stone every week. What kind of steels are you using and what kind of materials are you cutting and how frequent? And how often do you go to the rods?
Click to expand...
For the last month or so, I've only used a strop with Venev Diamond compound 5 passes on four grits; 3m (edit; 3.0m), 2m, 1m, 0.5m... Haven't had an issue yet, but we'll see. I've heard some upper end chefs only use strops (for years without stones). This has been for my BenchMade Bugout-mini and I'm only cutting boxes and cordages. I'd likely need stones if I was carving and making a bunch of feather sticks.
 
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I have relied on DMT hones for about four decades and have yet to wear one out (I maintain them by regularly wiping them down with BreakFree CLP). An Extra Coarse Dia Sharp (220) grit is useful for setting or reprofiling a bevel, but mostly I use an 8" DMT fine (red, 600 grit). Rarely I use the extra fine (green,1200 grit) on high carbon steel blades. Super steels with high vanadium content (S30V, S35Vn, S110V and tool steels like 3V and M4 seem to cut better with a slightly coarser edge -- take themto the 1200 grit and they don't have the same 'bite'. High carbon/low alloy steels, 10** series, Carbon V, 52100, etc., will take a much finer/polished edge. I rarely bother stropping.
 
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