Flattening waterstones with fine sand possible?

[ali27]

I flatten my waterstones on floatglass with SiC powder. The glass is
protected with mylar/polyester sheet. Sic powder is IMO just too hard and
It breaks down very quickly. I am looking for a loose abrasive that is fast and doesn't
break so quickly.

I am using 120 and 220 grit sic powder. After a few seconds the SiC
becomes much finer. Sometimes I also notice tiny black spots in my
waterstones which I am sure about is SiC particles. SiC is super hard,
9.3 on Mohs scale. I think because of the extreme hardness, the SiC
not only abrades, but also cuts in the waterstone and can get stuck.
I use practically no pressure, so I am not pressing the SiC in the stones.

I was googling for a softer abrasive. Found aluminium oxide which
is only slighlty ''softer'', 9 on Mohs scale. Too hard. Zirconia would be good
at 7.5 mohs scale. I have used Zirconia belts in the past and they
lasted a long time. Unfortunately I could not find zirconia abrasive
powder. I think the loose abrasive is also very expensive, but don't
know.

Sand has a hardness of 7 Mohs scale. It is about 5-6 times softer than
SiC. I know that Egyptians about 5000 years ago used sand as abrasive,
but I wonder if it would flatten waterstones. I am pretty sure sand will
do it, but it has to be reasonably fast.

Anybody tried this with sand? Would it matter if it were beach sand or
mason sand?

I have used wet and dry on glass and I did not like it. PSA 3m paper
is much better, but pretty expensive. Loose abrasive works, but I need
something less hard than Sic for the aforementioned reasons.

Thanks.

Ali27

 

[bridger]

go ahead and try it. how about the sand used for sandblasting? masons sand is probablt something like 30 grit, which sounds way too coarse to me.

 

[bugbear]

I have used wet and dry on glass and I did not like it. PSA 3m paper
is much better, but pretty expensive.

The majority of waterstone users use SiC on glass, "dry wall screen", diamond stones, or other waterstones.

I would be inclined to try these proven solutions before launching in to experiments, unless you particularly enjoy experimenting.

BugBear

 

[mu]

Drywall screen on granite or glass work well for me...

 

[Evergreen]

I occasionally flatten my combination waterstone on the large concrete pavings slabs in my garden. They're the plain surface ones. No water, no sand. It's rough and ready but it works to my satisfaction. And it cleans up the slabs a treat!

 

[ali27]

I have used wet and dry on glass and I did not like it. PSA 3m paper
is much better, but pretty expensive.

The majority of waterstone users use SiC on glass, "dry wall screen", diamond stones, or other waterstones.

I would be inclined to try these proven solutions before launching in to experiments, unless you particularly enjoy experimenting.

BugBear

Tried regular sand. Was way too coarse and it tore(?) through the mylar. So back
to Sic powder for now. And yes I do enjoy experimenting. Be prepared for a tiny
revolution in terms of flattening the back of plane blades very soon.

Bugbear, what thickness glass do you recommend for flattening waterstones? I have
12mm now, but I used the glass without mylar before and I am pretty sure it isn't
as flat as it should be. I was thinking of buying a piece of 50cm by 30cm, thickness
6mm. I want to use 6mm because it is cheaper and twice as light as 12mm, but not
sure whether 6mm would be stiff enough for waterstone flattening. If I remember
correctly a 12mm thick plate is 8 times stiffer than a 6mm thick plate.

Thanks.

 

[Jacob]

If you sharpen carefully you don't ever need to flatten your stones.
Saves a lot of bother!

 

[ali27]

Guys what about waterresistant mdf? MDF supposedly has good
flattness, but I am not sure whether even the green MDF stays flat
when water is used on it.

 

[woodbrains]

Hi.

I use wet and dry on my planer bed to flatten my coarsest stone and then use that to flatten the next coarse and then that for the next etc. if you use more. I only use 3 so that does it for me. The beauty is, you do it much more regularly so they are never very hollow and it is quick and easy to do. You could do it every time you sharpen if you had the mind to and three or four strokes is all it takes so it doesn't become a chore or a separate operation at all.

incidentally, Jacob, if you don't know what a waterstone is, then don't try to give advice. You cannot avoid making waterstones hollow with use and they will need flattening regularly. It is no biggie, it takes seconds and since they sharpen your blades five times quicker than oil stones you are still up on the deal.

Mike.

 

[János]

Hello,

Man made Japanese stones have aluminium-oxide as abrasive (the coarse ones silicium-carbide), natural waterstones contain Silicium-dioxide in the form of crystalline quartz, or as cryptocrystalline or microcrystalline material, that is: sand. So natural stones are hard as sand itself. Glass sand is a proven abrasive material.

Have a nice day,

János

 

[Jacob]

....You cannot avoid making waterstones hollow with use ....

You can if you use the whole surface and spread the load. Have a look at some of those Japs freehand honing on youtube.

 

[andy king]

....You cannot avoid making waterstones hollow with use ....

You can if you use the whole surface and spread the load. Have a look at some of those Japs freehand honing on youtube.

Over the course of time a stone will go hollow if you hone in an up and down the stone orientation, it's the nature of the beast.
You cannot start and stop a stroke smack on at the ends of the stone, so invariably the middle area tends to get more wear as more pressure is applied through the middle of the stone, easing off at the ends of each.
The old workaround used to be to use wedges at the ends of the stone flush with the top face, allowing that extra bit of surface area to keep the tool on the stone and not dip off the far end or crash into the front edge if you went too far.
Figure of eight honing is so say a better wear pattern for a stone, but in reality, a stone that wears, such as Japanese, natural or Indian, all maybe at different wear rates depending on their structure, will do so because of the way the honing process is done.
It will also end up with a dished effect across its width over time for the same reason - I defy anyone to be able to use the entire surface of a stone to all four edges with exact pressure in any honing operation!
That on it's own will have an effect on the flatness on any stone that wears away with use.

Andy

 

[David C]

Andy is spot on as usual.

There clearly was a need to flatten oilstones from time to time or we would not have the old recipe for flattening them.

"Silver sand and water on a York paving stone."

It is my view that careful craftsmen kept their stones flat.

Hollow stones may be fine for working a bevel but they play havoc with the flat side or back of a blade.

David Charlesworth.

 

[Jacob]

....You cannot avoid making waterstones hollow with use ....

You can if you use the whole surface and spread the load. Have a look at some of those Japs freehand honing on youtube.

Over the course of time a stone will go hollow if you hone in an up and down the stone orientation, it's the nature of the beast.
You cannot start and stop a stroke smack on at the ends of the stone, so invariably the middle area tends to get more wear as more pressure is applied through the middle of the stone, easing off at the ends of each.
The old workaround used to be to use wedges at the ends of the stone flush with the top face, allowing that extra bit of surface area to keep the tool on the stone and not dip off the far end or crash into the front edge if you went too far.
Figure of eight honing is so say a better wear pattern for a stone, but in reality, a stone that wears, such as Japanese, natural or Indian, all maybe at different wear rates depending on their structure, will do so because of the way the honing process is done.
It will also end up with a dished effect across its width over time for the same reason - I defy anyone to be able to use the entire surface of a stone to all four edges with exact pressure in any honing operation!
That on it's own will have an effect on the flatness on any stone that wears away with use.

Andy

In fact it's quite possible to over do it and make a stone convex over the length and width. Or you can straighten a dished stone by distributing the way you use it. I don't know why everybody says these things are impossible. More difficult if you only sharpen narrow chisels perhaps, but easy with wide ones or plane blades.
NB no special skill involved - you just decide what you are doing and keep an eye on your progress.
Jigs make it more difficult (impossible?) as they aren't so easy to run off the edges or ends of a stone.

 

[matthewwh]

Typical,

Can't just get man flu like the rest of us, has to get within feeler gauge range of death and then breezes back into society four months later with a characteristically concise answer as if nothing had happened.

A very warm and heartfelt welcome back David.

 

[David C]

Thanks Matthew!

David

 

[Jacob]

Yes welcome back DC hope you are well. Our posts crossed!

 

[andy king]

Yes, great to se you back David, I look forward to seeing you at a show some time!

Jacob, one word. Nonsense.
I have never seen a stone that has been worked convex by honing! I assume you have examples of this to show us all?
The concavity issue is pretty common, but you seem to be unable to admit the fact. I'd guess that anyone buying a well used secondhand stone putting a straghtedge over it would see a degree of dishing.
I'm sure you make these comments for arguement, they certainly seem to lack rational thought - only a CNC type operation could take any tool to the extremeties of a stones surface and distribute the pressure evenly each and every time, unless you are the one exception to the rule.

Andy

 

[Kodama]

Hello,

Man made Japanese stones have aluminium-oxide as abrasive (the coarse ones silicium-carbide), natural waterstones contain Silicium-dioxide in the form of crystalline quartz, or as cryptocrystalline or microcrystalline material, that is: sand. So natural stones are hard as sand itself. Glass sand is a proven abrasive material.

Have a nice day,

János

I wonder where you got this specific information from? I would love to know more about the subject, especialy if you have any info on the active particals in natural stones.

 

[Jacob]

This could be useful for those whose preferred sharpening method is to hollow stones and then flatten them.
Buy another stone and as you sharpen, hollow both stones, one after the other.
Then flatten them both together, one against the other.
At a stroke you'd no longer need all that kit: granite, glass, yorkshire pavings, diamond plates, silver sand, etc. etc. you name it!