How to flatten coarse stones?

[Jacob]

Its like pineapple Jacob it happens and then you deal with it #-o

Yebbut it's talked about as normal routine procedure. Every time you use a stone by some accounts.
I've hardly ever done it in my life.

Worth watching those Jap sharpeners on youtube and seeing how they spread the load over the whole surface of their stones.

 

[Modernist]

Cambering plane irons on a 1000 grip prep stone causes it to become high in the centre so you then simply change to running the centre of the blade along the edges of the stone and use the high centre to create the camber. When that wears away you simply change back to using the centre of the stone. Rocket science?

Re the 46 grit - bin it

 

[Tom K]

Cambering plane irons on a 1000 grip prep stone causes it to become high in the centre so you then simply change to running the centre of the blade along the edges of the stone and use the high centre to create the camber. When that wears away you simply change back to using the centre of the stone. Rocket science?

Re the 46 grit - bin it

Great except the OP had hollowed his stone and wanted a square grind. So if you have used your stone to produce a camber and hollowed it and you want to do a square grind at the earliest opportunity then you f_a_t_n it. see if you can fill in the missing letters. :shock:

 

[Modernist]

Cambering plane irons on a 1000 grip prep stone causes it to become high in the centre so you then simply change to running the centre of the blade along the edges of the stone and use the high centre to create the camber. When that wears away you simply change back to using the centre of the stone. Rocket science?

Re the 46 grit - bin it

Great except the OP had hollowed his stone and wanted a square grind. So if you have used your stone to produce a camber and hollowed it and you want to do a square grind at the earliest opportunity then you f_a_t_n it. see if you can fill in the missing letters. :shock:

I'd discounted the original stone as not fit for purpose and a waste of the OP's time. Normal stones are not a problem to flatten unlike his experience with the 46. so ---- --- :lol:

 

[Tom K]

Excellent recovery there Brian, how is your lovely tool cabinet settling in?

 

[Modernist]

Excellent recovery there Brian, how is your lovely tool cabinet settling in?

Fine thanks and glad you saw the joke. Just off to do some work from said cabinet and am looking forwards to the pleasure.

 

[Jacob]

Cambering plane irons on a 1000 grip prep stone causes it to become high in the centre so you then simply change to running the centre of the blade along the edges of the stone and use the high centre to create the camber. When that wears away you simply change back to using the centre of the stone. Rocket science?

Re the 46 grit - bin it

Great except the OP had hollowed his stone and wanted a square grind. So if you have used your stone to produce a camber and hollowed it and you want to do a square grind at the earliest opportunity then you f_a_t_n it. see if you can fill in the missing letters. :shock:

Perfectly possible to do a square grind on a hollow stone, but not easy. Basically you work the high points of the stone and keep an eye on the edge at intervals. In the process you flatten the stone. It's quite easy to go over and make it convex so it's all down to hand and eye skills, as ever. More than rocket science!

 

[Tom K]

Yebbut why make life hard?

 

[Jacob]

Yebbut why make life hard?

It's easier. You don't have to flatten your stones :roll: .

 

[Tom K]

Obviously you are right Jacob (at least in your reality) to produce a square edge use an out of square medium and fiddle. :roll: :lol:

 

[Jacob]

Obviously you are right Jacob (at least in your reality) to produce a square edge use an out of square medium and fiddle. :roll: :lol:

OK you do it your way!

 

[Tom K]

Yeah right I can suss you Butler your just lulling me into a false sense of security before you let leash with one of your profound and enigmatic anti toolie diatribes. :shock:
What would happen if we all did it our own way.....that way lies anarchy sez I (homer)

 

[Fat ferret]

How can hollowing stones be avoided? I use a figure of 8 pattern and the coarse side of my norton india stone has got quite bad. I have to grind things side on now.

 

[LuptonM]

I've flattened my dads india stones on some float glass using a sheet of coarse sandpaper. Oil stones take a while to hollow but my problem was that this coarse stone hollowed very quickly but I don't have anything coarse enough to flatten it. I just use coarse sandpaper on float glass /mdf for grinding now. Only problem is that I hate the clean up involved removing the spray adhesive/ ripped buts of sandpaper. I think a better solution would be to find cheap self adhesive rolls of coarse sandpaper

 

[Jacob]

How can hollowing stones be avoided? I use a figure of 8 pattern and the coarse side of my norton india stone has got quite bad. I have to grind things side on now.

Spread the load so it wears more evenly. It's easy to understand and easy to do, I don't know why so many find this a problem. It never used to be. Watch some of those Japanese plane sharpening videos.

.. this coarse stone hollowed very quickly ...

The stone (itself) didn't hollow at all - YOU hollowed IT!
If you don't want them hollow just stop doing it! It is not rocket science.

 

[pedder]

How can hollowing stones be avoided? I use a figure of 8 pattern and the coarse side of my norton india stone has got quite bad. I have to grind things side on now.

Spread the load so it wears more evenly. It's easy to understand and easy to do, I don't know why so many find this a problem. It never used to be. Watch some of those Japanese plane sharpening videos.

.. this coarse stone hollowed very quickly ...

The stone (itself) didn't hollow at all - YOU hollowed IT!
If you don't want them hollow just stop doing it! It is not rocket science.

Hi Jacob,

this post doesn't help at all. Obviously hollowing is a problem for many woodworker. There are too many bad second hand chisels to deny that fact.

Why not link to one of "those Japanese plane sharpening videos"?
If it is not rocket sience (whatever that is) why not telling how to do in a few words?

Cheers
Pedder

 

[Jacob]

How can hollowing stones be avoided? I use a figure of 8 pattern and the coarse side of my norton india stone has got quite bad. I have to grind things side on now.

Spread the load so it wears more evenly. It's easy to understand and easy to do, I don't know why so many find this a problem. It never used to be. Watch some of those Japanese plane sharpening videos.

.. this coarse stone hollowed very quickly ...

The stone (itself) didn't hollow at all - YOU hollowed IT!
If you don't want them hollow just stop doing it! It is not rocket science.

Hi Jacob,

this post doesn't help at all. Obviously hollowing is a problem for many woodworker. There are too many bad second hand chisels to deny that fact.

Why not link to one of "those Japanese plane sharpening videos"?
If it is not rocket sience (whatever that is) why not telling how to do in a few words?

Cheers
Pedder

Start here
Loads of examples. But very variable. Some are not even Japanese and are using "transitional" methods. But you can see clearly in many of them that they are using the whole face of the stone. Some of them can be seen to freshen up the surface with a quick pass of something or other, but this isn't quite the same as "flattening"
These are mostly water-stones but you do the same with oil stones.
Re telling how to do in a few words how many words are needed in addition to using the whole face of the stone, spreading the wear etc? What is there to explain?
It's similar to flattening a piece of wood - to avoid making a hollow, or a hump, you work on reducing the high points - or better still - spread the work so you don't create them in the first place.

PS chisel sharpening jap style here
This chap seems to have done a load of videos using different sorts of stones and tools.

Here's another. He starts by freshening the surface and then proceeds to use the whole face - changing position and shooting right off the ends.
There's loads of them and an interesting voyage of discovery if you open some of the links to the right. Could take you anywhere!

http://www.youtube.com/watch?v=g69Xj7u3 ... re=related

 

[Modernist]

Life is too short

 

[Corneel]

Long time lurker here. Maybe I can add something to this thread? I like Jacob's posts a lot, but I would like to give some more perspective, from my point of view of course.

First I think everybody agrees that flat stones are nice to have to save time when you go from a coarser to a finer grid. When all the stones are flat you don't need to spend time on the fine stone to confirm the chisels shape to a concavity or whatever.

This week I watched a DVD from Lary Williams about sharpening. That really made me think of this thread. He is a long time, very "oldfashioned", oilstone user. Free hand sharpener etc. He made a point to flatten your stone before each sharpening! Just a few swipes with a coarse DMT in his case.

From my own experience I know that I don't keep my waterstones flat. Of course I try to distribute wear, but nonetheless they hollow after a while. I could intensify my training to keep the stones even flatter, checking with straight edges for example until I get the whole thing wired. At the other hand, I could also pick up the stone and the DMT, walk to the sink and return with a flat stone 10 seconds later.

These are two different strategies. I applaud you Jacob for being able to keep your stones flat without ever flattening them. But the other method is valid too and produces equally sharp edges.

Knowing myself I will of course try to follow Jacob's model, but in the mean time I'm glad with my DMT xcoarse.

 

[Jacob]

....... He made a point to flatten your stone before each sharpening! Just a few swipes with a coarse DMT in his case.

I do the same but just every now and then with a Diapad. But not to flatten (though it will a bit) but just to freshen up the surface

.... I applaud you Jacob for being able to keep your stones flat without ever flattening them.....

Well you shouldn't really as it's not that difficult.
It's horses for courses though - I've got at least one well used stone which is hollow end to end but straight across the width. Doesn't affect sharpening in any way. I've got into the habit of working more on the high ends, so it will be flatter in time.