Coarse synthetic stones in 2023

[user 16756]

I am sure many of you are, like myself, on the eternal quest for a coarse stone that doesn't suck. I do think things are a bit better these days, I have been a happy Debado 180 user for a while now, but I am curious what folks think is good in world of coarse stones, as this does seem to be a place where there may be recent developments. I really wouldn't hate something a bit faster tbh; it's slow going, but it's harder than most and I feel like I can shape bevels pretty decently with it which I like.

(in before sandpaper comments, I do have a kasfly)

 

[ethompson]

Same boat here, always looking for a better setup for coarse work, particularly major projects where I’m doing heavy work on straightening or altering the placement of shinogis.

Just ordered some coarser options of the NSK diamond stones and will report back with my findings there

 

[blokey]

Love the Debado 180/200, also love the Nanohone 100, fast but there is a lack of feedback. Since you mentioned Kasfly I do love mine with Trizact paper too, tho funnily I find them works great with iron and stainless cladding, but feels like glass with high alloy steel.

 

[captaincaed]

Yep.
I was looking around, heard some word that debado 180 batches can be inconsistent. I’m still on a pink brick I sealed with lacquer to tame the thirst (works great fyi). @Kiru recommended the Shapton glass 120 (correct me if wrong) plus the puck to unload swarf.

Diamonds may be ok, but I think the hard binders mean the diamonds can often leave deep grooves. After learning razors the past 6 months or so, bevel setting on diamond leaves scratches that can be very time consuming to remove, depending on the stone. The naniwa 3k leaves grooves that a 4k synthetic can struggle with. Same with the gesshin 1k. That said the BBB 400 scratches come out ok with just a King 1k and not too much sweat. So not all stones are the same. That stone is just remarkable in some way every time I pull it out. Not sure how it would be on stainless cladding, I gather that’s a make or break moment for many diamond stones.

So the hunt goes on. Maybe a real knife maker will chime in. @milangravier or @Isasmedjan maybe.

 

[kpham12]

I am sure many of you are, like myself, on the eternal quest for a coarse stone that doesn't suck. I do think things are a bit better these days, I have been a happy Debado 180 user for a while now, but I am curious what folks think is good in world of coarse stones, as this does seem to be a place where there may be recent developments. I really wouldn't hate something a bit faster tbh; it's slow going, but it's harder than most and I feel like I can shape bevels pretty decently with it which I like.

(in before sandpaper comments, I do have a kasfly)

Shapton Pro 220 is my old reliable. Cuts fast, never clogs or even slow down much and relatively cheap. I’ve gone through several of them and always go back. A bit muddy/messy, but it just keeps cutting. And the scratches are deep, but even and consistent. I like it better than the Pink Brick 220, King/Sun Tiger 300 (green), King 300 (blue), King 220, Shapton Glass 220 which I feel is a bit slower and a couple others I’ve tried.

Recently got a Debado 200 and it dishes super slow, good for shaping bevels, but it doesn’t cut as fast as I would like and needs refreshing with the nagura or an Atoma pretty frequently. Doesn’t clog as fast as the Shapton Pro 120, but more than I would like. Anyone else have this problem? Maybe I got one from a bad batch.

I’ve heard good things about the Nanohone 200, it’s next on my try list.

 

[tostadas]

The coarsest I've gone down to recently is jns 300. It works and leaves relatively shallow scratches for what it is. But I'm also curious what you guys like for coarser options.

 

[ian]

Mostly use Sigma 240 atm. Works reasonably well as long as you keep it hydrated and refresh the surface once in a while. Wouldn’t mind getting something diamond tho.

 

[M1k3]

I've been using Shapton Pro 120 on stainless cladding, Sigma 240/Norton India or Crystolon coarse on mono.

Eventually want to get the Venev 100/240 stone though. Or maybe the 100 micron Nanohone.

 

[Qapla']

+1 to Suehiro Debado LD 180 here. It's effectively replaced my old Nubatama Black 180, since the former is splash-and-go.

 

[captaincaed]

Shapton Pro 220 is my old reliable. Cuts fast, never clogs or even slow down much and relatively cheap. I’ve gone through several of them and always go back. A bit muddy/messy, but it just keeps cutting. And the scratches are deep, but even and consistent. I like it better than the Pink Brick 220, King/Sun Tiger 300 (green), King 300 (blue), King 220, Shapton Glass 220 which I feel is a bit slower and a couple others I’ve tried.

Recently got a Debado 200 and it dishes super slow, good for shaping bevels, but it doesn’t cut as fast as I would like and needs refreshing with the nagura or an Atoma pretty frequently. Doesn’t clog as fast as the Shapton Pro 120, but more than I would like. Anyone else have this problem? Maybe I got one from a bad batch.

I’ve heard good things about the Nanohone 200, it’s next on my try list.

Is that what you used to blast through that beefy workhorse (kaeru?) from your videos this past year?

 

[kpham12]

Is that what you used to blast through that beefy workhorse (kaeru?) from your videos this past year?

Yup, SP220 does the heavy lifting on most knives I mess around with. I remember once, they were on sale for $29 on Amazon and I only bought 2. Should’ve stockpiled more.

 

[inferno]

i like the 220 pro and glass, also the sigma 240 is good if sealed.
sometimes i use the 120 pro but i'm not so sure its really that much faster than the 220ies for typical knives. sic powder on the 120 speeds things up a bit.

if i feel i need faster than this then its off to the floor sander or some angle grinder disc in my drilling machine. you have to be careful with the machines though.

 

[Delat]

I’m a total noob but I’m really liking the nanohone 100 micron diamond resin (about 120 JIS and FEPA). No loading, no dishing, and nice even scratches. Definitely liking it a lot more than my SG220. No feedback as someone else noted, but I’ll happily trade that for time saved. I’ve been using much lighter pressure with it vs the SG220 which makes the whole process a lot more relaxed.

So far I’ve used it to thin the hardened primary bevel of an AEB-L s-grind and soft stainless cladding of another knife. My SG220 really struggled with the AEB-L which was the impetus for me to get the nanohone.

 

[Up_dog128]

I feel like I'm perpetually on this quest for the bangin-as* rock that gets that knife thin in a hurry like it's on Slimfast. Even though I do most such work on belt grinders, esp for low-mid tier knives for customers, some things are just better done by hand.
Personally, I didn't like the SP 200; it cuts fast, but it dishes super fast and gets that mud all over the place.
I've been using the SG stones lately, and of the 3 coarsest grits (120, 220, 320) I think I like the 220 best. It seems to cut just about as fast as the 120, but the scratches aren't as deep and I like the way it feels a bit better; I do think it is a bit softer than the 120.
I've just started trying out the american mutt, mostly just for thinning stainless clad R2 so far (I should preface here that nothing is really cutting this cladding very fast, including this stone, so this is all relative). In case anyone is unfamiliar, this stone is made of the tailings from the manufacture of other stones, and is mix of SiC, AlOx and diamond, and is stated to be around JIS 110 in grit. Initial impressions are mixed... Seems to cut pretty fast, wears quite slow, clogs up a bit, and disgorges big nasty particles every few seconds that scratch deep and feel bad under the blade. These particles are big enough to put visible gouges in the stone, kinda like if you just started using a coarse diamond plate without breaking it in first. I would def recommend flattening this stone before initial use, which I didn't do cuz I don't have any very coarse SiC powder right now. This stone seems like it wasn't mixed well enough before being sintered, as there are spots/areas of the stone that feel very different from other areas, both under the finger and under the blade. It is also claimed that the mixed grits leaves a finer finish than would be expected at this grit, bit that hasn't been the case so far- the scratches are deeper than either my SG120 or my Atoma 140 (although this Atoma has been at the party for a while). I might try it on some reactive damascus cladding tomorrow and report back after further experience.

Also figured I'd drop this here, since we just had this convo and there may be something of interest in it for anyone reading this thread when-flattening-bevels-removing-low-spots-how-do-you-know-if-the-stone-you-are-using-isn’t-coarse-enough.63491

 

[user 16756]

Hmm, lot of old favorites. Seems like the nanohone stuff, which is newer, is good.

Same boat here, always looking for a better setup for coarse work, particularly major projects where I’m doing heavy work on straightening or altering the placement of shinogis.

Just ordered some coarser options of the NSK diamond stones and will report back with my findings there

I was looking at those too, please do report!

 

[ethompson]

Hmm, lot of old favorites. Seems like the nanohone stuff, which is newer, is good.



I was looking at those too, please do report!

Got them in yesterday, will get some time to play around with them in the next week or so hopefully

 

[Delat]

Here's the scratch pattern on vtoku2 core w/soft stainless cladding off the nanohone 100 micron diamond resin. I didn't spend a lot of time on it, maybe 15 mins, just wanted to ease the curve higher up on the blade road. Nice even scratch pattern, no random super-deep scratches. I love that there's no loading, dishing, or mud to deal with and I can use light pressure vs getting sore fingers with my SG220.

Only question mark is longevity, but I'm hoping it lasts for years (light home use) since it's diamond impregnated resin, not surface bonded like a plate.

 

[Choppin]

@kpham12, @inferno - how do you compare the SP and SG 220? I’m on my second SG220 and never tried a SP.

Pretty happy with it BTW, but I’m curious to try the Nanohone 100. Definitely relate to the sore fingers thing with SG…

Do you really need the Nanohone lapping plate to lap it? Or can I just forget about lapping and assume it barely dishes for the home user?

 

[mengwong]

If the 100 is good, is the 200 better? Asking for my shopping cart…

By this logic I’m going to end up at “honey? Can I see your engagement ring for a minute? Just need to ease this spine”

 

[Delat]

@kpham12, @inferno - how do you compare the SP and SG 220? I’m on my second SG220 and never tried a SP.

Pretty happy with it BTW, but I’m curious to try the Nanohone 100. Definitely relate to the sore fingers thing with SG…

Do you really need the Nanohone lapping plate to lap it? Or can I just forget about lapping and assume it barely dishes for the home user?

My plan is to not worry about it until I need to worry about it, which I’m hoping will be a long, long time. I think @daveb has been using the nanohone 100 micron for a while though so maybe he can comment if it’s showing any signs of wear.

 

[inferno]

@kpham12, @inferno - how do you compare the SP and SG 220? I’m on my second SG220 and never tried a SP.

Pretty happy with it BTW, but I’m curious to try the Nanohone 100. Definitely relate to the sore fingers thing with SG…

Do you really need the Nanohone lapping plate to lap it? Or can I just forget about lapping and assume it barely dishes for the home user?

the pro is twice as thick as the glass, 15mm. glass is 7-8mm. but unless you glue it to something it will probably break in half at 3-4mm.

the glass is a faster stone. at least in regular use. for me.

glass wears less for the same amount of metal removed.
i'm not saying the pro is fast wearing but the glass wears slower.

pro is muddier.

stone economy - i have a feeling your will abrade about the same amount of steel when both stones are worn out.

-------------

i have the almost finished glass at work (i use it very seldom there). and 2 glued together 220ies at home where i use coarse stones more.

btw dishing is not really a big problem with coarse stones. they all wear fast so you just spread the wear to flatten it. sure it wont ever get truly flat, but do you actually need a truly flat coarse stone?? i very seldom do. and if i do i have diamond plates.

 

[Choppin]

btw dishing is not really a big problem with coarse stones. they all wear fast so you just spread the wear to flatten it. sure it wont ever get truly flat, but do you actually need a truly flat coarse stone?? i very seldom do. and if i do i have diamond plates.

agree on dishing… on coarse stones I’m actually more concerned with glazing/loading. as long as it keeps cutting, it’s fine. and IME the SG220 is great at that, takes some time to start loading and even then becomes less fast but keeps cutting.

but yeah, I do want flat coarse stones when flattening single bevels / wide bevels… not so important on convex grinds though

 

[inferno]

there is no glazing or loading at all with the pro 220imo and if any, very minor with the glass 220. both these stones release a good amount of grit in use to prevent them from loading or glazing.

personally i dont give a flying F about a flat C stone. even if im flattening a bevel i can direct the wear of the stone and on the steel. to simply make it flat in the end. usually the problem is removing the material. in a fast enough way.

i work on mostly dished coarse stones when i make my knives. i prefer to make single bevel santoku type knives. except the rear side is mirror flat and the 2 fron bevels are also mirror flat. and also all sides are mirror polished on stones. and this works out quite well without ever flattening the 220ies. its mostly the high grit stones that needs to be flat imo. 1k and above. and those are only for erasing the low grit scratches.

i made this knife with a lot of stone work. and the coarse stones were flattened maybe once. when the whole **** was like 97% done on those coarse stones. stones 50€ - knowing how to use them - priceless.
its a 12 shapton pro finish iirc or possible the ss12k. thats as mirror as it gets on stones. fyi.
https://www.kitchenknifeforums.com/threads/my-first-knife.45405/my camera is very "unforgiving" to microscratches since i know how to use it. shot on an iphone this would all be a complete mirror i guess. but thats not really the case in reality. and i try to shoot realistic ****.

so imo just learn how to use the stones to their maximum effect. i try to use my stones without flattening them to be a cheapass mf.

 

[coxhaus]

Anybody looked at the Xtra Coarse diamond stone? It is currently on sale at 50% off at Woodcraft. I think I might buy one. I can use it on my axes and lawnmower blades.

 

[inferno]

coxhaus - get an angle grinder for your lawnmower. maybe 60 grit flap discs for the coarse work and then some 120 or 150 or so for the delicate surgeon work 2 minute job.

i personally prefer blue bosch angle grinders but there are a lot of other inferior brands of course. and those work too i guess.

 

[coxhaus]

coxhaus - get an angle grinder for your lawnmower. maybe 60 grit flap discs for the coarse work and then some 120 or 150 or so for the delicate surgeon work 2 minute job.

i personally prefer blue bosch angle grinders but there are a lot of other inferior brands of course. and those work too i guess.

I usually use my bench grinder, but I have to be careful not to overheat the steel. I have several grinders and I think one is a blue Bosch. I have a couple of flap discs that I use for polishing steel. I will try your solution. I probably need to buy a 60 grit flap disc. So, the flap disc don't round the edges?

 

[kpham12]

the pro is twice as thick as the glass, 15mm. glass is 7-8mm. but unless you glue it to something it will probably break in half at 3-4mm.

the glass is a faster stone. at least in regular use. for me.

glass wears less for the same amount of metal removed.
i'm not saying the pro is fast wearing but the glass wears slower.

pro is muddier.

stone economy - i have a feeling your will abrade about the same amount of steel when both stones are worn out.

-------------

i have the almost finished glass at work (i use it very seldom there). and 2 glued together 220ies at home where i use coarse stones more.

btw dishing is not really a big problem with coarse stones. they all wear fast so you just spread the wear to flatten it. sure it wont ever get truly flat, but do you actually need a truly flat coarse stone?? i very seldom do. and if i do i have diamond plates.

Yup, literally all of this. Especially about the SP220 breaking sometimes when it gets a bit thin. I think the SP220 is a bit faster than SG220 for me, but I use a lot of pressure and mud. But yeah, Glass seems to dish slower but Pro is thicker so it’s about even.

 

[inferno]

I usually use my bench grinder, but I have to be careful not to overheat the steel. I have several grinders and I think one is a blue Bosch. I have a couple of flap discs that I use for polishing steel. I will try your solution. I probably need to buy a 60 grit flap disc. So, the flap disc don't round the edges?

of course they do if you tilt your hand. i suggest to mount the lawnmower blade in a vise. and do long straight strokes.

the results will depend on your skill. 60grit will run the coolest and 150 or so the hottest so you need to move fast the higher you go in grit to not burn the steel. since you now have more surface area contacting and then increased friction and therefore heat. works the same with belt grinders too.

good thing with angle grinders is that if you have a slim one, maybe 5-600w then you can get almost open hearth surgical with them if you use a light touch. and move fast enough. if **** turns blue then you move too slow.

 

[coxhaus]

OK, I ordered a 60g flap disc. I am going to need to mow soon so I will try it.

 

[Blank Blades.]

I picked up the gritomatic 120 (i think, im pretty sure it was 120 not long ago). Its a silicon carbide soaking stone. I bought it for the purpose of thinning, and putting the final geometry on knives I'm doing in steels like cpm 10v, and other highly wear resistant steels.

If i work a slurry up with a truing stone, it will cut 10v just as good or better than most things ive tried, though this definitely isn't what i would call a normal thinning task most people can relate to. What i can say, is something with a relatively soft cladding i think would be no problem for this stone. The abrasive is fairly consistent, and over all seems like a good stone.

I picked up whats supposed to be the new version of the american mutt not long ago. I havent used it enough yet to comment on it though. I can say, its an interesting feeling stone.

If you really want the absolute fastest thinning. And you have something that needs a lot of material removed. The manticore is your stone though. Its 60 grit silicon carbide. So the scratches it leaves are DEEP. But if you also have a 120 grit to follow it up for the final stretch of the thinning, it will cut down your time on the stones a good bit.

Also kinda recently i got the king 220. I picked it up for the same reason i got the gritomatic. Trying to find a good stone for thinning very wear resistant steels. This one does the job very well, its just not quite coarse enough for it to make sense for the majority of the work. Its friable enough that on any normal knife its going to do well.

But unless you are getting some kind of bonded diamond, or cbn abrasive. The reality is, if you want a fast stone for thinning. Youre going to need something fairly friable. If its not releasing abrasive, youre not going to keep cutting the steel effectively.

Side note. I see people complain about the shapton pro 120, loading up a good bit. Not just in this thread but others. There are a few things you need to do to use it effectively.

1) never flatten it with an atoma 140. You're going to condition the surface in a way thats not going to allow for optimal performance. If you want to flatten it. Use 60 grit loose sic powder, or a 60 grit trueing stone.

2) DO NOT wash the slurry that starts forming off when youre thinning. Its going to basically keep conditioning the stone as you go, and keep it cutting. Just ad bits of water as needed.

3) do use a decent amount of pressure, at least at first until you for a slurry. You can also concentrate pressure on the cladding. Softer steel will allow a slurry to form easier.