Finishing grit for skinning knives?

[HeavyHanded]

CBN used in a slurry will self align and cut like a milling operation - strips of metal rather than scratch removal due to the mineral cutting along its edge.
I do not believe diamonds share this trait as they are shaped much like most other abrasive minerals. A broken in diamond plate will have greater uniformity across its surface, so fewer minerals will be proud of their fellows to dig deeper, disturbing the subsurface less perhaps. Some conventional abrasives have advantage of less stable binder, so proud abrasives simply get tore loose before they can cause much harm.

When it comes to finishing low carbide/alloy steels I not only think there is no need for superabrasives, I find conventional AlumOx and SiC do a slightly better job. YMMV

 

[DeadboxHero]

CBN used in a slurry will self align and cut like a milling operation - strips of metal rather than scratch removal due to the mineral cutting along its edge.

Interesting, I've never seen or heard of this feature, is this based off of empirical evidence or something that was read and extrapolated?

A broken in diamond plate will have greater uniformity across its surface, so fewer minerals will be proud of their fellows to dig deeper, disturbing the subsurface less perhaps.

I never knew there was a CBN plate to compare to a Diamond one. I'm assuming there was some kind of comparison?

There can be a large disparity between what some folks consider broken in and worn out. Like when a 400 grit plate is cutting very slow and making a surface roughness finish like a 1000grit stone.
I'd say it's worn out if it's not working like a 400grit stone anymore. I have a pile of worn plates sounds like I should resale as "Broken In"

Some conventional abrasives have advantage of less stable binder, so proud abrasives simply get tore loose before they can cause much harm.

Well Aluminum Oxide and Silicon Carbide are softer and less sharp so they don't cut as deep.

When it comes to finishing low carbide/alloy steels I not only think there is no need for superabrasives, I find conventional AlumOx and SiC do a slightly better job. YMMV

If you're looking for higher polish I agree. However, If you want cutting speed with less dishing there is no substitute for super abrasive stones.

 

[HeavyHanded]

Interesting, I've never seen or heard of this feature, is this based off of empirical evidence or something that was read and extrapolated?

I've seen it in photographs of the removed metal. CBN creates strips like a drill bit in aluminum due to the edges of its cubic shape. IDK if it has the same effect in a bonded surface.

I never knew there was a CBN plate to compare to a Diamond one. I'm assuming there was some kind of comparison?

I'm only talking about mineral shape, and comparing plated diamond to a vitreous stone, not a CBN one.

There can be a large disparity between what some folks consider broken in and worn out. Like when a 400 grit plate is cutting very slow and making a surface roughness finish like a 1000grit stone.
I'd say it's worn out if it's not working like a 400grit stone anymore. I have a pile of worn plates sounds like I should resale as "Broken In"

By "Broken in" I mean the stray bits and proud minerals from the plating process are knocked off and the bonded layer is a uniform plane. Worn out is worn out...

If you're looking for higher polish I agree. However, If you want cutting speed with less dishing there is no substitute for super abrasive stones.

Less dishing, but if the mineral is much harder than the steel, it cuts about the same speed. My diamond plates don't cut any faster on carbon steel or low alloy stuff than a SiC stone or AlumOx Waterstone. Arguably I can press harder on the waterstones without creating a pressure burr (or ripping out abrasive minerals), if anything they're faster but only due to increased applied force.

My experience with bonded diamonds is that they're even slower yet.

 

[DeadboxHero]

I've seen it in photographs of the removed metal. CBN creates strips like a drill bit in aluminum due to the edges of its cubic shape. IDK if it has the same effect in a bonded surface.

I haven't seen this feature in my experience with bonded CBN stones, even with slurry on vitrified bonded ones.

I'm only talking about mineral shape, and comparing plated diamond to a vitreous stone, not a CBN one.

Ya keep saying mineral and it's driving me crazy
Mineral seems to apply only to naturally occurring inorganic solids. Like those found in natural stones. These are all synthetic abrasive grains. Also while diamond is naturally occurring the geometry of the grains that are grown and sorted are not and are more uniform than the natural mineral variety.

Should just be called "grains" not minerals

By "Broken in" I mean the stray bits and proud minerals from the plating process are knocked off and the bonded layer is a uniform plane. Worn out is worn out...

Seems everyone is different, I've met folks that swear they had there diamond plate for 20 years and it's still going yet we all know it died long long ago.

Less dishing, but if the mineral is much harder than the steel, it cuts about the same speed. My diamond plates don't cut any faster on carbon steel or low alloy stuff than a SiC stone or AlumOx Waterstone.

Well it would be interesting to coat a single layer of Aluminum Oxide and Silicon Carbide to a plate to really compare

Arguably I can press harder on the waterstones without creating a pressure burr (or ripping out abrasive minerals), if anything they're faster but only due to increased applied force.

Gotta love bonded stones.

my experience with bonded diamonds is that they're even slower yet.

Seems you only tried the resin stones from Jon and didn't like them.


There is only 1mm of abrasive/bond stone and the bond is rock hard to take advantage of the harder longer lasting Abrasive grains.

If we made a Aluminum Oxide or Silicon Carbide stones with the same resin bond at high hardness that stone will be even slower.


If we made the Diamond resin bond softer it will cut faster but the softer bond will shed the diamond prematurely. $$$

There are faster stones than Resin bonded.

The metallic bonded and vitrified bonded cut much faster but $$$

Trade offs all around.

 

[Mr.Wizard]

My experience with bonded diamonds is that they're even slower yet.

If this chart is correct you could use a much coarser resin-bond diamond stone and get the same surface roughness as a finer electroplated diamond one. How did that factor in?

 

[Mr.Wizard]

Well it would be interesting to coat a single layer of Aluminum Oxide and Silicon Carbide to a plate to really compare

If you accept resin bond that is readily available for all three in the form of 3M Microfinishing Film.

 

[DeadboxHero]

True dat.

I use the 3M 675L 120um Diamond resin film on my 2x72 for finishing hard, high carbide steel blade grinds at low speed with water cooling. The difference in longevity is startling, but it's also a $75 belt

If you accept resin bond that is readily available for all three in the form of 3M Microfinishing Film.

 

[Mr.Wizard]

DeadboxHero Have you tried that belt on soft steel and is it faster than a 120µm ceramic belt at the same drive speed?

 

[DeadboxHero]

Sure, if they have the same film backing.
I'd only use for hard, high carbide steel though due to cost.
$3-6 per belt vs $75 per belt.

DeadboxHero Have you tried that belt on soft steel and is it faster than a 120µm ceramic belt at the same drive speed?

 

[HeavyHanded]

Ya keep saying mineral and it's driving me crazy
Mineral seems to apply only to naturally occurring inorganic solids. Like those found in natural stones. These are all synthetic abrasive grains. Also while diamond is naturally occurring the geometry of the grains that are grown and sorted are not and are more uniform than the natural mineral variety.

Should just be called "grains" not minerals

Diamond, AlumOx, SiC are all naturally occurring and manufactured. CbN is the only truly man made grain among the bunch.

Seems everyone is different, I've met folks that swear they had there diamond plate for 20 years and it's still going yet we all know it died long long ago.

I have some plates that are going strong for years, my fine tapered rod from DMT has sharpened hundreds of serrations and ground a bunch from scratch and it still cuts great. I have a couple plates that seemed to wear after only a few hours of total use and now they collect dust at work waiting for some utility task unrelated to sharpening.

Well it would be interesting to coat a single layer of Aluminum Oxide and Silicon Carbide to a plate to really compare

I've compared new diamond to new Alumox lapping film and there was no difference that was obvious. Individual mineral durability isn't an issue with a vitreous or ceramic bonded stone, compared to cost the standard abrasives are a better choice for budget steels in my opinion.

Seems you only tried the resin stones from Jon and didn't like them.

I've tried from two other mfgs as well and was equally unimpressed. Returned them actually and I don't care to elaborate on the makers. Its not that they didn't "work" but that they were slow as molasses, loaded easily, and edge quality on non-super steels was sub par. Plated diamond may have its own shortcomings but has grind speed comparable to vitreous stones, works great on high carbide steels and the plate thickness uniformity makes it a great choice for my guided system.

If I could only have one type of sharpening tool for a full range it would be plated diamond, and I'd live with it in situations where it is just OK. For utility work and no need for a range of finishes the combination Crystalon does it all.

 

[Mr.Wizard]

I'd only use for hard, high carbide steel though due to cost.

No doubt.

 

[HeavyHanded]

Have you tried that belt on soft steel and is it faster than a 120µm ceramic belt at the same drive speed?

Maybe apples to oranges, but the 125micron diamond belt compared to Norton Blaze 120 at the same speed is no comparison, Blaze is considerably faster. Surface finish is nicer off the diamond. But one is a woven backing and the other film.

But yes, the diamond belt lasts multiples of usage time if it is cared for.

 

[HeavyHanded]

If this chart is correct you could use a much coarser resin-bond diamond stone and get the same surface roughness as a finer electroplated diamond one. How did that factor in?

I was comparing rated grit to rated grit. Honestly once I discovered no real difference below 400 grit or so I stopped trying to make it work.

 

[DeadboxHero]

Diamond, AlumOx, SiC are all naturally occurring and manufactured. CbN is the only truly man made grain among the bunch.

chemically yes, but they are not taken directly out of the earth in as is condition and slapped into a stone. They are chemically synthetized and sorted to different types. I feel mineral implies non man made, naturally occurring.

Also I've used "mineral water" and it didn't increase cutting performance on my stone.*crude attempt at humor

I've compared new diamond to new Alumox lapping film and there was no difference that was obvious. Individual mineral durability isn't an issue with a vitreous or ceramic bonded stone, compared to cost the standard abrasives are a better choice for budget steels in my opinion.

I still use my Choseras for the appropriate steels, if I had the money I'd be rocking a nice Japanese natural waterstone on the appropriate steel as well to chase the desired finish and aggression.

The objective and preference is king unless the steel type and use demands otherwise.

I've tried from two other mfgs as well and was equally unimpressed. Returned them actually and I don't care to elaborate on the makers. Its not that they didn't "work" but that they were slow as molasses, loaded easily, and edge quality on non-super steels was sub par. Plated diamond may have its own shortcomings but has grind speed comparable to vitreous stones, works great on high carbide steels and the plate thickness uniformity makes it a great choice for my guided system.

Plated stones make a rougher finish and have less longevity, that is a fact. The deeper scratches may also have some disadvantages for mechanical characteristics of the edge.

Bonded stones are the answer to those issues at an increased cost.
The main advantage to plates is they are cheaper and make better microserrations due to the deeper scratches if so desired. Also,they flatten ceramic stones the fastest.

There are three major bond types for Diamond/CBN.

Metallic, vitrified and resin.

Resin is the cheapest, finishes the highest, cuts the slowest and is prone to loading but has most dish resistant of all renewable surface stones.

tool for a full range it would be plated diamond, and I'd live with it in situations where it is just OK. For utility work and no need for a range of finishes the combination Crystalon does it all.

Sounds like you don't like the hard resin bonded stones. There are more options out there. It would be erroneous to apply the properties of hard resin bonded stones to all bonded types to dismiss the merits of all bonded Diamond/CBN stones.

Lots to explore.

 

[DeadboxHero]

Maybe apples to oranges, but the 125micron diamond belt compared to Norton Blaze 120 at the same speed is no comparison, Blaze is considerably faster. Surface finish is nicer off the diamond. But one is a woven backing and the other film.

But yes, the diamond belt lasts multiples of usage time if it is cared for.

That is a definite apples to oranges comparison

A film backing vs a Y-wt backing will have big differences even with the same grit and abrasive type.

 

[DeadboxHero]

The deeper you go down the hole it becomes more difficult to pick any absolute favorites.
I think having a specific purpose like skining helps narrow it down. I gave my recommendation in an earlier post. That's what I'd use and give my customers for that purpose if that's what they are after. Pick another task and I'm sure I'd pick a different stone. With different stones bringing out different properties it's no wonder why folks have many many different stones when they geek out really hard.

Thanks, I now have a new grail stone! Well, one or two... Considering the price for two sided plates I am seeing on Amazon, its also slightly more affordable than buying multiple DMT plates. This is exactly the type of esoteric knowledge I am seeking. Just to go a bit deeper down the rabbit hole though, what are your absolute favorite stones?

 

[HeavyHanded]

Sounds like you don't like the hard resin bonded stones. There are more options out there. It would be erroneous to apply the properties of hard resin bonded stones to all bonded types to dismiss the merits of all bonded Diamond/CBN stones.

I agree, but can also say I'm not putting aside cash to try any more of these out, having come to the conclusion that it isn't worth it. For rough work any quality stone will do (which what led to this side discussion). I have a couple of diamond jointering stones IIRC the abrasive is 10 micron but they leave a very 8-10k ish finish and were very economical. The high carbide steels really only need the superabrasives at the finishing steps although for cosmetic work it does pay to use a superabrasive start to finish if only for longevity sake.

 

[DeadboxHero]

For rough work any quality stone will do.

I disagree with that based on my experience and testing but for example, if a man felt the bottom of a ceramic mug is all he needs I can't argue against that either. Too each their own, but it won't stop me from sharing my experience and opinions.

I'll agree to disagree.

 

[nutsforknives]

So I'm trying to get the benefit of diamonds but my current setup is all water stones except for 1um and 0.5um diamond paste. I am thinking about getting a Venev bonded diamond plate in 6um/2.5um. Do you think I could get most of the benefits by going Shapton Glass 320(45um) > Suehiro Cerax 1k (18um?) > Venev 6um > Venev 2.5um > 1um strop > 0.5um strop? Trying to avoid buying redundant gear, im already a bit sour about my Rika 5k and 8K stones being useless for s30v and m390 lol. Hopefully dropping $100 on a Venev plate will get me to a point where I have adequate tools to sharpen any knife to a high polish. I think this should work, as long as I spend enough time with the 6um diamonds to sharpen out the mess left by the 1k/18um AlO stone. What do you guys think?

 

[Eli Chaps]

So I think, regardless of stone type, one pretty common theme in the recommendations has been that for what you want, lower grits are preferred. You seem committed to higher polish.