coarse sharpening stone

[Assaf Oppenheimer]

Hi all, my plane found the leftovers of a staple in some maple end grain and now I have a chipped edge. I am looking to buy a really coarse stone to redo the bevel.

my stones right now are the
Atoma 400 (I use it for flattening the ceramics)
Shapton pro 1000, 5000, 12000
DMT Dia-Sharp fine, x-fine, xxfine ( I use those mainly for edges that would gouge the ceramics - my Shapton's are my workhorses)

I am trying to decide between a Shapton pro 120 DMT xxcoarse (120 mesh) and Atom 140 (If I hear justification, I might consider a DMT Dia-flat). one of the things I was wondering is if I get the Shapton, can I use the Atoma 400 to flatten it? or will it be coarse enough to wear the Atoma out?

eventually I will get a grinder but right now, space and cost are at a premium

any advice would be appreciated

[Luke Dupont]

Sandpaper!

[Rob Luter]

I use a 300 grit diamond stone (Trend) for that sort of thing. If it's really bad I use a slow speed grinder to completely restore the primary bevel.

[Rafael Herrera]

Sandpaper!

Yes, 80 or 120 grit sandpaper will grind away damage in minutes, with or without a guide.

A coarse crystolon stone will also deal with nicks quickly.

[David Publicover]

Before I got a grinder I used coarse wet/dry sandpaper on a piece of glass or a granite plate. It worked well.

[Jim Koepke]

Another voice for abrasive sheets aka sandpaper.

The bigger the nick the coarser the paper. Most of the time my blades only need a 200-300 grit. 80 grit can make for a very rough bevel that is hard to smooth. The surface left by a 200-300 grit abrasive is easy to work smooth with a 1000 grit stone.

jtk

[Andrew Pitonyak]

If you plan on eventually buying a grinder, just do it and be done with it. I have both a dry grinder (slow speed) and a Tormek.

Although I do really like my Norton coarse crystolon stone / India Stone such as this:

https://www.amazon.com/gp/product/B000XK5ZDY

The biggest disadvantage to those are that you might start wondering "how do I flatten the crystolon stone" and then start spending even more money on things such as carbide crystals and glass... not that I have ever bothered to do it and I own the carbide crystals and the glass to do it.

I use my coarse stone so infrequently for things such as plane blades (and because I own two grinders), I no longer own any coarse water stones. When it really matters, I find it easiest to use sandpaper as mentioned by others. I usually only end up doing this when flattening backs since I can do the bevel so quickly on my Tormek.

[Joe Bailey]

I am looking to buy a really coarse stone to redo the bevel.



Since you asked about a stone ...

I will second the advice re: the Norton Crystolon stone.

https://www.sharpeningsupplies.com/Norton-Crystolon-Bench-Stone-8-x-3-P24C206.aspx

This is a synthetic stone that has been around a long time. Use a light, non-drying oil. It is easy to load it to the point that it stops cutting.

[Tom M King]

After reading this thread, I just ordered one of these:

https://www.sharpeningsupplies.com/The-Grinder-Stone-P1655C71.aspx

I used to use an X coarse diamond plate, but it didn't last as long as one might think. I never liked it.

[chuck van dyck]

I’d give what ya already own a shot first!

Unless they are huge chips you can get a good bit done with a 400. I agree its nice having one that doesn’t see steel, but don’t make a habit of it. ¯\_(ツ)_/¯

Clamping some 220 on a piece of mdf works too.

A grinder can be found pretty cheap on clist.

[Rafael Herrera]

After reading this thread, I just ordered one of these:

https://www.sharpeningsupplies.com/The-Grinder-Stone-P1655C71.aspx

I used to use an X coarse diamond plate, but it didn't last as long as one might think. I never liked it.

Given that I already own them, my preference is for 8x2x1 sized stones (No. JB8, Norton Part No. 61463685455, for example.) The stone you and Joe above quoted are 1/2" thick and 3" wide. I would guess they'll dish in the center and become sort of fragile as they get thinner. A combination coarse/fine stone at 2" will dish only lengthwise, one could still use them without cambering the blade.

Single grits:

Fine: Norton Item No. FJB8, Part No. 61463685515
Medium: Norton Item No. MJB8, Part No. 61463685520
Coarse: Norton Item No. CJB8, Part No. 61463685525

Wow, they stock big ass combination stones at that site:

11-1/2" x 2-1/2" x 1" Stone: Norton Item No. JUM3, Norton Part No. 61463685840
12" x 2-1/2" x 1-1/2" Stone: Norton Item No. JUM4, Norton Part No. 61463685855

[Andrew Pitonyak]

After reading this thread, I just ordered one of these:

https://www.sharpeningsupplies.com/The-Grinder-Stone-P1655C71.aspx

I used to use an X coarse diamond plate, but it didn't last as long as one might think. I never liked it.

Be sure to post and let us know what you think. I noticed that stone.

The coarse Crystolon is listed as about 120 grit. The one you just ordered is listed as 80 grit. That is a very rough / fast stone.

[Jim Koepke]

Be sure to post and let us know what you think. I noticed that stone.

The coarse Crystolon is listed as about 120 grit. The one you just ordered is listed as 80 grit. That is a very rough / fast stone.

Likely with that big of diamond grit not only are they fast to cut, they are fast at diamonds chipping and wearing down.

My favorite coarse stone:

469496

This is ~four feet long. With a pressure sensitive adhesive backed abrasive sheet it can warm my fingers when using a guide or flattening a back.

It was purchased from a monument shop (tombstone carver) years ago for $25. One of my better sharpening stone investments.

jtk

[Tom M King]

I will post about that 80 grit stone, when I have a chance to use it. My coarse stones get used rarely. I have 120 Shapton, 300 King, 400 Sigma, and don't think I have anything else until I get to 1,000, but I have, and use so many stones that I don't even remember all of them. I start with the least coarse one necessary for the particular job. When I'm in a big planing job, 6,000 is the starting point when the iron gets sharpened. Oil stones stay in the truck.

My chisels get used for all sorts of rough work, working on old houses, so not something the average woodworker needs. I can't grind inside those houses, because of the mess it makes. My sharpening sink has a 92" stainless drainboard, with built in sink. It always goes to the job site. Not for the garage shop either, but makes having all those stones easy to use.

[Joe Bailey]

Likely with that big of diamond grit not only are they fast to cut, they are fast at diamonds chipping and wearing down.

jtk

It appears you're under the impression that the stones being discussed are diamond plates -- they are not. Both the Crystolon and the one Tom ordered use Silicon Carbide.

[Joe Bailey]

After reading this thread, I just ordered one of these:

https://www.sharpeningsupplies.com/The-Grinder-Stone-P1655C71.aspx

I used to use an X coarse diamond plate, but it didn't last as long as one might think. I never liked it.

Thanks for that -- I didn't know that one existed -- I too, just ordered one.

[Jim Koepke]

Likely with that big of diamond grit not only are they fast to cut, they are fast at diamonds chipping and wearing down.



It appears you're under the impression that the stones being discussed are diamond plates -- they are not. Both the Crystolon and the one Tom ordered use Silicon Carbide.

When grit numbers are given it doesn't occur to me the discussion is about oilstones.

Are the Chystolon stones labeled with grit numbers?

jtk

[Luke Dupont]

Likely with that big of diamond grit not only are they fast to cut, they are fast at diamonds chipping and wearing down.

My favorite coarse stone:

469496

This is ~four feet long. With a pressure sensitive adhesive backed abrasive sheet it can warm my fingers when using a guide or flattening a back.

It was purchased from a monument shop (tombstone carver) years ago for $25. One of my better sharpening stone investments.

jtk


Whoa, what is that? Just a big piece of granite / whatever tombstones are made of?

I've always wondered what random stones one can find that would work, and I've always wondered if having a massive stone conveys any benefit speed wise (I've always used a lot of short strokes on my stones, but then I've never owned anything longer than 8")

I don't have, and may never have the space for a large wheel grinder or tormek or something. One day, though, for the fun of it, I want one of those big old hand cranked or treddle grinding wheels. One day, when I have the space and won't be moving every couple of years...

I see these old little bench/table mounted hand cranked grinders a lot though. Are these worthwhile, or is one better served by sandpaper or a nice coarse crystolon stone?

[Mark Rainey]

I see these old little bench/table mounted hand cranked grinders a lot though. Are these worthwhile, or is one better served by sandpaper or a nice coarse crystolon stone?

Luke, I bought a new Prairie Tool Company water cooled hand cranked grinder from Drew Langsner about 20 years ago. I do not think they make them any more. I have used it a few times over the years and have not mastered it. You crank with one hand and hold the blade with the other. Just can't get good results.

[Andrew Pitonyak]

When grit numbers are given it doesn't occur to me the discussion is about oilstones.

Are the Chystolon stones labeled with grit numbers?

jtk

For each stone, they usually use terms such as coarse, medium, and fine along with statements such as this:


The coarse grit stone quickly restores worn edges; medium grit produces a good edge needed for most tools; and fine grit produces an even sharper edge. Ideal for hand dimensioning and sharpening of all types of knives, plane blades, chisels, scrapers, or any other tool that needs a flat, sharp edge, working best when used with oil.

They do mention general grit sizes on this page:

https://www.nortonabrasives.com/en-us/resources/expertise/choosing-sharpening-stone


Man-made benchstones come in a variety of sizes and shapes and are available in a range of grit sizes: coarse (80-100 grit), medium (150-220 grit), and fine (280-320 grit). Benchstones are durable, wear slowly, and retain their flatness significantly longer than waterstones.


I have found listed "approximate" grits for crystolon compared to the India stones along with the reasons that the India stones will leave a "finer" surface for the same grit size as indicated by coarse, medium, and fine.

I really like your large stone. Do you sharpen on the stone, or, do you use adhesive backed sandpaper?

[Jim Koepke]

Whoa, what is that? Just a big piece of granite / whatever tombstones are made of?

Yes Luke that is a big piece of granite the tombstone shop had laying around the yard. He often uses scraps like that to make smaller stones for markers for people who want to have a memorial for a pet.


I really like your large stone. Do you sharpen on the stone, or, do you use adhesive backed sandpaper?

Andrew, I purchased a bunch of rolls of adhesive backed sandpaper from > https://www.supergrit.com/ < many years ago. Now that my tool restorations are fewer and further between it isn't used as much as in the past.

jtk

[Chuck Hill]

I have the coarsest Atoma plate and love it. It cuts fasts and does not degrade quickly like some other ones (DMT in particular, I have a dead one of those). If you go for diamonds, go for Atoma.

[Scott Clausen]

I get a offcut from a granite countertop installer about three feet long. Cover it with painters tape and apply from a roll 90 grit PSA paper. I can move up to 120 and 220 before going back to diamond plates. Primary use is flattening the sole of the plane.

[Assaf Oppenheimer]

A grinder can be found pretty cheap on clist.

slim pickings in Israel

[Assaf Oppenheimer]

thanks everyone, I ended up deciding to get the 3m Stikit gold 80 grit and stick it on the atoma. I was using porter cable junk and it would wear out within 10 strokes. hopefully this will work better.

[Rafael Herrera]

Just an example of using a silicon carbide type of stone (a Carborundum in this case, but a Norton Crystolon would be equivalent), this freshly made plane iron needs its bevel to be ground for the first time. What you see is the rough bevel ground prior to heat treatment. There's a bit less than 1/32" of steel to remove. On that combination stone in the picture, it took about 15 minutes to get an apex ready for further honing.

469860

After grinding.

469861

why do it this way? it's just a different method, one small stone and plenty of oil. A PSA sandpaper strip and a honing guide would have worked, but you have to watch and not burn your fingers.

[Tom M King]

The big, coarse stone came a couple of days ago, but I haven't had a chance to try it on an edge yet. It is Big, and I recognized it from rub "bricks" for tile work. It is nice, and flat on all surfaces.

I was looking through Bon Tools stonework tools, and ran across their selection of rub stones. Those are only 6" x2", but I ordered a 24 grit, and a 46 grit, mainly to see what they will do to a beat up chisel. If they are way too coarse, I'll use them sometime for their intended purpose.

https://www.amazon.com/gp/product/B00BC2HIBE/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

[Andrew Pitonyak]

Okay, now that's very interesting.

[Tom M King]

The 24 grit and 46 grit stones came today. I played with them a little bit, because also some chisels I bought off ebay came. These chisels need to be reground, so I wasn't worried about them.

MAN!! do these things eat metal! I don't think you can skip grits though, because the scratches are pretty deep. The 46 made quick work out of the 24 scratches, and the 80 made pretty quick work out of the 46 scratches.

I just played with them for not even a minute. I'll need to set up to check the bevel angles before I do any more with them.

It would be nice if the really coarse stones were larger, but they're useable this size.

Even the 80 grit stone is pretty fast. I used to have an X-coarse diamond plate, that I never really liked. I already like this 80 grit stone better.

[Joe Bailey]

After Tom, brought this to our attention, I ordered one of the coarse SiC stones from Sharpening Supplies (the link is back up in Tom's post #9)

I recently gave it a go, and it is everything I'd hoped for. This is a 12" x 3" x ¾" man-made stone containing 80 grit Silicon Carbide.

My woodshop has absolutely no power tools of any kind. (electricity is used for lighting and music only). Though I have about 20 vintage hand-cranked grinders, they are annoying to use.

I've had my share of coarse diamond plates (short-lived) and experimented with sandpaper, but so far, this thing is the best.

I freehand ground a couple of nicked and chipped #6 irons as well as two or three chisels in the same condition. None had a recognizable bevel angle when I started.
I have ground and honed freehand for decades now, and can get within 2 or 3 degrees of 25° with no problem. The coarse grit and long runway had the steel shaped in no time.

As recommended, I used only water as a cutting agent.

Time will tell how long this stone lasts, before potentially loading up like every other Crystolon-style stone I've ever encountered. But for now, this is a fantastic substitute for a powered grinding wheel.

[Tom M King]

Thinking about loaded up Cyrstolon stones, and others that I have no idea what they are, just in the accumulation of old stuff, started me thinking about cleaning them. One thing I haven't tried is a pressure washer. I haven't really tried anything, because these are old stones that I have never used. I have a small, convenient to use 120v pressure washer now, so I'm going to try that.

[Tom M King]

This one just came today. I'm just putting it here so I won't forget it whenever I get to try them out.

https://www.amazon.com/gp/product/B00849ZSV0/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

I'm going to need to set up the 20" wet masonry saw pretty soon. When I get around to that, I'm going to use an old diamond blade to try slicing off some of one of the old, loaded up stones that I found here, just to see how it works.

I bought one of the knock-off Eclipse clone jigs to use on the coarse stones. I have two originals, one that I bought new, but I don't want to roll them on these rough things.

[Luke Dupont]

The big, coarse stone came a couple of days ago, but I haven't had a chance to try it on an edge yet. It is Big, and I recognized it from rub "bricks" for tile work. It is nice, and flat on all surfaces.

I was looking through Bon Tools stonework tools, and ran across their selection of rub stones. Those are only 6" x2", but I ordered a 24 grit, and a 46 grit, mainly to see what they will do to a beat up chisel. If they are way too coarse, I'll use them sometime for their intended purpose.

https://www.amazon.com/gp/product/B00BC2HIBE/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Do these load up? Do you use water / oil with them? Do they stay flat / can they be flattened?

As someone who also lacks a grinder and who has been somewhat unsatisfied with sandpaper for flattening the backs of tools in need of much TLC, I'm really interested in a good coarse stone that is better than your standard crystolon and longer lasting than super coarse diamond plates.

[Rafael Herrera]

Crystolon stones don't stay flat. Fresh 60 or 80 grit PSA sandpaper should get any tool's flat side clean and ready for a diamond stone or whatever else you want to use. There's nothing more aggressive than crystolon, but one has to use it where it's lack of flatness doesn't matter as much.

As per loading, if one uses plenty of oil, it's not an issue, at least it's not for me and I use them quite a bit when refurbishing a damaged blade.

[Luke Dupont]

Crystolon stones don't stay flat. Fresh 60 or 80 grit PSA sandpaper should get any tool's flat side clean and ready for a diamond stone or whatever else you want to use. There's nothing more aggressive than crystolon, but one has to use it where it's lack of flatness doesn't matter as much.

As per loading, if one uses plenty of oil, it's not an issue, at least it's not for me and I use them quite a bit when refurbishing a damaged blade.


I think I've only tried crystolon-type stones that were not oil filled in the past. Water and oil both soaked right through and couldn't prevent clogging.
I'll have to try one of Norton's oil filled crystolons at some point.

Or, just figure out what the equivelent of "PSA" sandpaper is called here...

[Tom M King]

I'm not able to answer questions about them yet. Been too busy with other things to do anything but play with one of them yet. My to-do list is long. They do EAT metal.