Different Waterstone Flattening Questions

Re: Different Waterstone Flattening Questions

GolfSteve in Calgary

>Dave, it is very hard to keep the stone flat while sharpening. I have not been able to do it. I try to cover the entire surface of the stone while sharpening, but invariably the middle eventually gets dished. For me this takes about 10 minutes on the 1000 stone.

I then flatten the stones as follows:

1. rub two 1000 grit stones together. It is important to use a combination of small circular movement, large circular movement, figure eights, and long straight strokes. I also turn one of the stones sideways for a little bit. The use of the different patterns helps to avoid the "spherical/concave" problem discussed below.

2. Once I have two flat surfaces (one on each of the 1000 grit stones), I can flatten the other side of the 1000 stones if I want using the same process (I use both sides of my stones).

3. Now use one of the flat faces on the 1000 stone to flatten your 8000 stones. Ensure that you use the variety of movements described above. If, after a while, the 1000 stone doesn't seem to be cutting the 8000 stone, rinse the stones in water, then continue flattening.

You can feel when the stones are flat (or at least parallel) by the suction/friction between the stones.

ps. Are you sure that your straight edge, which you are using to check your stones, is straight? I used a 12" steel rule for a while, but then found out that it is a "ruler", not a straight edge - it was a 16th to a 32 of an inch out - enough that I thought my stones weren't flat. In actual fact my stones were flat but my ruler was crooked.

A Qustion for Dave

Alan Hamilton

>Dave,

As I was catching up on this thread today, and read your reply to me--about how long it would take you using an 800 stone--it finally sank in... To me it sounds like it's taking you much, much too long, and so you have to flatten your stones many too many times.

So now the question:

How much of the back are you trying to flatten? Only the bit near the edge? (In practice the tool is flat only near the edge, and the "flatness" tapers off up the back.) Or are you trying to make the entire back mirror-finish flat?

If you're trying to do the latter, I think I know why you're having so much trouble.

Alan

Pressure

GolfSteve in Calgary

>One thing that I don't hear discussed very often is the amount of pressure to put onto the iron while flattening it.

I don't put much pressure on the iron - maybe two to three times the weight of my hand. My knuckles certainly aren't turning white.

When I'm trying to get the final mirror polish I increase the pressure a bit.

Re: Only need two stones

Tom Williams

>But you couldn't arrive at this using a figure-eight motion, could you?

Re: Different Waterstone Flattening Questions

Dave (Arlington, VA)

>Hi Steve -

Thanks for you additional post and observations about how you go about sharpening and flattening your stones.

As far a pressure is concerned, I have wondered about that. I certainly am not bearing down on the blade, but neither is it just skimming the surface. I guess I've considered it to be a light-to-moderate pressure.

As far as my straightedge is concerned. When I flatten the stone dry and can tell because of the difference in the color of the stone that it is flat, no light gets under my straightedge (though it is a ruler whose gradient is only valid for "20 degrees C"). While when I flatten it with W/D sandpaper or drywall screen during flattening, light peeks out between it and the stone in the center (but not along the edges). So I have a fair amount of confidence in it.

Again, thanks for your post.

Regards -

Dave

An answer... of sorts

Dave (Arlington, VA)

>Hi Alan -

Funny you should ask. I have wondered about this question of how much of the back to flatten. I suppose since one only needs two straight planes of metal to intersect one could flatten just a quarter inch or sov(I've never measured it).

But I do flatten more than a quarter inch. No hard and fast size - but I have noticed when I flatten blades that on many (especially older blades) the bottom inch or inch and a half of the blade gets shinnier than the rest of the blade. I have assumed that this was the portion of the blade that was either tempered or hardened (I'm not sure which - frankly I'm not "sure" its either).

So, I generally just flatten the "shinny" part of the blade: on some that's as little as 3/4 of an inch, for most its probably more like and inch or an inch and a half.

I've kinda taken this "flatten blades just once" to heart - though in truth I probably don't have enough time left on this earth to use up an inch and a half of steel on a plane blade. So, perhaps I'm just making their next owner (hopefully my children) that much happier.

What are your thoughts on how much of a blade back to flatten?

Regards -

Dave

Re: Only need two stones

William R. Duffield, on the Cohansey

>With a figure-8 motion, but without rotation, you cannot even guarantee sphericity. You have to slide the pair of surfaces against each other, and also rotate one with respect to the other.

Re: Three surfaces or three stones?

Fred Krow

>Dan,

How flat is your ceramic flattening stone? I was temped to purchase one last week however, the two I checked (in the local Woodcraft store) with a straightedge were not at all flat. The had a dip on ends of about .008-.010

I called Woodcraft main office tech. and requested they check the ceramics in stock,,,,the rep. checked with the $40 straight edge and used a feeler gauge,,,,he stated his was about .008 out at the ends.

Regards,

Fred Krow

Re: An answer... of sorts

Alan Hamilton

>Dave,

I'm sorry not to get back to your sooner. I kind of dropped out for a couple days.

I think trying to make mirror bright the entire back of a tool is an enormous waste of time. Aesthetically it might make the tool more beautiful--but then that's confusing the tool with the work. (No offense to all the tool makers: for tool makers the tool is both).

I certainly don't try to flatten the entire back of anything. When sharpening I lay the back of the tool across the width of the stone and move it in little circles from one end of the stone to the other. This means the bit behind the bevel is always on the stone, but above that the time any part of the tool is on the stone tapers off higher up. Obviously, this means only the bit behind the bevel gets the complete treatment.

Amazingly enough--at least to me--there are some that actually indulge in this enormous waste of time and insist on flattening the entire back of their tools.

Quite a while ago, here or elsewhere, there was a fellow (a woman would never be so stupid) who asked your question, "why is it taking me so long," though he was flattening the entire back of all his bladed tools. No logical arguments or appeals to reason would dissuade him: he was going to flatten--and make mirror bright--all the backs of all his bladed tools. But he still didn't understand why it took so long. Sigh.

Alan

Re: An answer... of sorts

Pam Niedermayer - Austin, TX

>Oh, oh, let me look again, yep, I'm a woman. :) I'll disagree a bit here, I flatten the entire back; but it only has to be done once. When sharpening the bevels/bezels after the first time and a burr is raised on the back, I lightly take off the burr, or sometimes simple pound it off.

Where being a woman comes in handy is that we know why it takes a long time. :)

Pam

Re: An answer... of sorts

Alan Hamilton

>Pam,

As a user of many Japanese tools, do you completely pound out the backs so you can flatten them entirely?

Just kidding. I certainly meant no offense by my previous post; and I hope none was taken. In fact, I was thinking especially of you when I made that unfortunate generalization.

You have always seemed wholly practical and utilitarian (not the philosophical "Utilitarianism" system of ethics as espoused by John Stuart Mill, Jeremy Bentham, et al) in choosing and using your tools, I can't help wondering why you polish the backs of your tools. So why do you?

Alan

Re: An answer... of sorts

Pam Niedermayer - Austin, TX

>Absolutely no offense taken, just a couple of people disagreeing. And just in case anyone may be confused by all this, no, I don't pound out the backs so I can flatten them entirely; although, I would tap out a low spot here and there if one ever occurred.

As to John Stuart Mill and Utilitarianism, I am a fan, am an econ major after all. There's something beautiful in utility; although insufficient to satisfy all aesthetic needs, I enjoy using a good and beautiful tool.

That said, the reason I flatten the backs is to gain a reference surface. I want to know that when I start to chisel or plane, I can count on the back to guide me. If it's even 1� off flat for the last 1/2", I'd lose that reliance, often trying to chisel the air rather than the wood.

Pam

Thanks, Alan !!!

Dave (Arlington, VA)

>Hi Alan -

Thanks for your reply to my earlier post. Sorry for the delay in getting back to you. I hate it when work gets in the way of woodworking and tools.

I'm sure that one of the reasons its taking me so long to flatten these backs is because I'm trying to flatten too much of the back.

But I think it may also have something to do with volume and previous condition. I'm trying to flatten the back on 8 bench plane blades, 4 chisel blades, one #78 blade, three #71 blades, one #271 blade, two #79 blades, two block plane blades, and twelve #45 blades. I feel like I have some inkling of how Steve Knight must feel at times. Sadly, I've procrastinated sharpening these flea-market/garage sale acquisitions over the last couple of years.

Only two of these are aftermarket blades, the rest are "new-to-me" blades. Many are/were pitted - some (especially some of the #45 blades) were severely pitted.

Also most of the blades were previously Scary Sharped. I feel like Scary Sharp has worked for me in the past, but this go-round I was getting serious dubbing on both the leading edge and the sides. In fact, much of what I'm doing on the blade I'm currently flattening with my waterstones is getting rid of the dubbing cause by Scary Sharp. This virtually stunned me because I thought this blade had already been flattened and a had an almost mirror like surface from edge to edge up to 600 grit. Well that almost morror like surface is mocking me right now as it continues to shine after working my waterstones, but only on the edges (about 1/16th of an inch on both sides). I'm at a loss as to how it dubbed that much. I can only assume that somehow I must have started 'rocking' the blade as I tried to flatten it.

Nonetheless, I think your right, and in the future I think I may try to sharpen a much smaller part of the backs of the blades (plane blades, that is).

Regards -

Dave