Different Waterstone Flattening Questions

Re: Different Waterstone Flattening Questions

GolfSteve in Calgary

>The more coarse the stone, the less frequent the flattening. The frequency of flattening depends a bit on what you're doing, but I find that my 1000 stone needs flattening about every 10 minutes, my 8000 stone needs flattening about every 5 minutes.

I don't bother checking with a straight edge, I just flatten by habit. Flattening only takes 20 seconds, so I don't think it's a big deal.

Re: Different Waterstone Flattening Questions

Steve Knight

>of course it depends on the stone. every brand wears differently. it depends on how you use it what the stroke pattern is what steel you use on it how well you flatten it.

usualy the courser stoens wear faster so need more flattening.

How often to flatten

Steve Elliott

>When I flatten a blade back, I keep working on the coarsest stone until I'm getting an even scratch pattern on the entire blade area to be flattened. Then I flatten the stone and go back to work. The middle of the blade is invariably a little high because it came off a stone that was dished out. By the time the entire blade back is again touching the stone, it's almost flat and the stone is only dished a little. Depending on the softness of the stone and the original condition of the blade, another quick round of stone flattening may be a good idea.

It's worth taking the time to get the back really flat while using the coarsest stone because it reduces the time spent on finer stones.

When flattening the stone, there are several ways I can tell that it is not flat:

1. The way the stone moves on the W/D sandpaper changes as it becomes flat. A stone that is high on the ends tends to want to twist around as I move it, and its movement changes as the high end of the stone goes past the edge of the sandpaper. (I always move the stone back and forth parallel to its long dimension, to reduce its tendency to roll.) As the stone becomes flat, it moves more evenly and predictably.

2. By watching the grit left on the sandpaper, I can tell which parts of the stone are high. When the stone leaves an even amount of grit wherever it touches the paper, it's flat.

3. The stones I like are a different color after they've removed some steel. Light-colored stones are the best this way, although my dark red 800x King stone also shows gray areas clearly. These darker areas grow smaller and then disappear when the stone if flat. A few stones have natural variation in color, and some retain rust-colored stains that go below the surface even when the stone is flat, but most stones will be even in color over their entire surface when they've reached flatness. One of my least favorite stones is a Shapton 320x, which is such a dark blue that I can't see any color change. The 120x Shapton is a lot better due to its white color. If I buy any more Shaptons, I'll be careful to pick grits that are light-colored.

Twenty years ago I used oilstones. While they wore more slowly, they definitely did go out of flat, as I found out a couple of years ago when I tried using them again. Stones that I had considered perfectly serviceable were actually way too dished out for me to use today.

Re: Different Waterstone Flattening Questions

Alan Hamilton

>Dave,

With my waterstones, unlike GolfSteve's, the coarse stones dish much, much more quickly than the finer stones. I remeber reading somewhere why that is so; IIRC it has to do with the size of the abrasive chunks and the clay--or whatever--that forms the matrix.

Sorry I cannot be more scientific. Perhaps someone else knows.

As to how often to flatten them: I flatten my 800 grit stone after every tool I sharpen and/or flatten; even more often if there's a lot of steel to remove.

My finer grit stones I flatten less often. I believe this is because the really heavy work is done on the coarser stones, and the fine stones are really just erasers to get rid of the scratches left by the coarse stones.

I reaize this isn't all that helpful. I remember when a friend was showing me how to grind valve seats. The tool was put in the valve stem hole in the head, and then turned around and around. I asked him your question. "How long do I have to do this?" He answered, "until it's done." Not very exact, but it really is the only correct answer.

Alan

Re: Different Waterstone Flattening Questions

Jim in Burlington Ontario

>Starting with 220 is way to course IMO your making more work for yourself.

Re: Different Waterstone Flattening Questions

GolfSteve in Calgary

>I have Norton waterstones. The 1000 grit stone definetely wears the least. The 8000 grit stone wears fairly quickly.

I also have a 4000 grit stone. I didn't mention it because it seems to be an anomoly. It wears so incredibly fast that I rarely use it unless I am trying to flatten a large area (such as the back of an iron). I've worn off about 1/4 of the 4000 grit stone (rarely using it), but have hardly dented the 1000 and 8000 stones that get regular use.

Re: Different Waterstone Flattening Questions

Dave (Arlington, VA)

>Thanks for letting me know your experience with the Nortons. I still haven't gotten off my 220 yet. So I'll be interested to see if my experience mirrors yours with the 100, 4000 and 8000.

Your 20 second "no big deal" flattening comment has me a bit depressed. So far I've been working on the backs of a #78 blade, and six bench plane blades and while I can get the 220 stone flat dry, I still am struggling to keep it flat during the sharpening sessions.

I a blade back for 30 strokes on the right hand side of the stone, then rotate it around and flatten again for 30 strokes.

Then yesterday I would take it over to a piece of 220 grit W/D sandpaper to flatten the stone - with only limited success. Then tonight I'd follow the same flatten procedure of the blades but to keep the stone flat I used a piece of 220 grit drywall screen.

In both evenings, by the end of the session, the stone were still dished in the middle - not a lot, but enough to be annoying.

Oh, well - I guess the experimenting will continue.

Again, thanks!

Dave

Re: Different Waterstone Flattening Questions

Dave (Arlington, VA)

>Steve -

Thanks for the post. I use a figure eight motion when I sharpen, and my blades are mongrels picked up at flea markets, garage sales and estate sales (except for two Hock blades).

Even with my limited experience I'm finding your right - different blade are sharpening differently. They even make a different sound when being flattened.

Again, thanks.

Dave

Re: How often to flatten

Dave (Arlington, VA)

>Steve -

Thanks for your post. I especially appreciated your detailed observations on how the stone moves and the swarf behave as the stone gets flat on the W/D sandpaper. I've been looking for that kind of pattern, but I haven't seen it yet. I'll keep looking!

I was a bit confused by your first couple of sentences. I didn't really understand how sharpening with a slightly dished stone seems to work out in the end. Forgive me if I misunderstood you - because later in the post I know you encourage me to make sure I keep my stones flat (especially the course grit one).

Again, thanks!

Dave

Re: Different Waterstone Flattening Questions

Dave (Arlington, VA)

>Hi Alan -

Thanks for your post. It takes me quite a while to get a blade flat with my 220 stone. I imagine that an 800 would take even longer.

Also I certainly don't mind the "you just know" answer. That's the way it is for many, but sometimes you stumble across someone who's figured out how it is that they just know.

I still think I must be doing something wrong because I flattening my stone multiple times during the flattening of each blade and I'm still ending up with a mildly dished stone.

Oh, well.

Thanks again.

Dave

Re: Different Waterstone Flattening Questions

Dan Donaldson

>I have a Norton 220 and it seems to wear down very fast. In fact, so fast that it is almost irritating. I am thinking of trying a 220 Shapton to see if it is better.

Re: Different Waterstone Flattening Questions

Don Thompson, Cutler Ridge, South of Miami FL

>FWIW, Harrelson Stanley of Japanese Tools (also the distributor of Shapton stones, I believe) recommends sharpening chisels on waterstones as though you were trying to flatten the waterstone with the chisel, i.e., trying hard to use all of the surface, in order to avoid premature dishing. It seems as though your Norton 220 may be a bit soft, so perhaps this approach would be of help.

Just a thought...

Three surfaces or three stones?

Dave (Arlington, VA)

>Hi Dan -

Sorry to hear of your frustration with your Norton 220s. Since this has been my experience too this is making me wonder about the woman who did the sharpening methods comparison a while ago in FFW where she rated Nortons as "excellent" in ease of use.

Oh, well. In my quest to keep my 220 flat during sharpening, I'm now leaning toward getting another 220 (good money after bad?) and using it to keep my first 220 flat.

I've heard that you need to be able to abrade three surfaces (? - I can't remember for sure if it was three stones) to keep all three flat. Two surfaces will leave them mated, but one will be convex and the other concave.

What I don't know is - if I'm using only one side of one of my 220s for sharpening could I use both sides of another to keep all three sufaces flat? Would you happen to know the answer to this question?

Seems like I could just keep a plastic tub of water next to my sharpening station (with the "extra" 220 soaking in it) and periodically take my "user" 220 and abrade its surface with the two surfaces of the "extra" stone.

Seems like this might be slightly less messy - but more importantly might give this relative novice better feedback on when my stones were flat again. Then I could use my flat 220s to keep my other stones flat. Am I dreaming?

Any thoughts?

Regards -

Dave

Re: Different Waterstone Flattening Questions

Dave (Arlington, VA)

>Don -

Thanks for the post. At this point, I'm pretty much trying everything I can think of.

I have been using a "figure eight" motion. Maybe now I'll try a staight back and forth (or really side to side) motion starting with the front of the blade and progressively moving the blade closer to the center of the stone. Then rotate the stone and try the same thing from the other side.

I know that's not what you were recommending (specifically), but maybe I'll give it a try and see what happens.

Again, thanks!

Dave

Re: Three surfaces or three stones?

Dan Donaldson

>The three stone method requires that you use all combinations of the three. You would not be able to rub the two sides of the same stone together to get the third set;-) I have a ceramic flattening stone, but it is just that the 220 goes out of flat so soon, and I have already worn about 1/4 of it just keeping it flat. I am still leaning toward a Shapton to see how it works. I have two of them right now, and they seem to stay flat a lot better than others that I have used.

Re: Three surfaces or three stones?

Dave (Arlington, VA)

>Hi Dan -

You know, that was my suspicion - as I thought about this. I knew I could abrade A against B, and A against C, but not B against C - the flaw in my reasoning (and the reason for the "three stone" part of my question). Thanks for the confirmation.

On ceremic flattening stones, won't they go out of flat too? Then what do you do? Diamond stones? I started a thread about them a week or so ago, and found a variety of experiences here at WC in terms of whether they were flat (out of the box) and how long they stayed flat.

As far as Shapton's are concerned. I thought about them, I just couldn't bring myself to fork over the cash for a complete set - not to mention the lapping plate. Would you plan to get the Shapton's with or without the lapping plate? If without, how would you plan to keep them flat? Your ceremic flattening plate? W/D sandpaper (seems like you'd go through that pretty fast)? SiC on glass? Drywall screen?

Thanks for your post!

Regards -

Dave

Only need two stones

Tom Williams

>The three stones method is technically correct, but not necessary. I believe it derived from a technique for making straight edges, where you are comparing three linear objects to each other. If you rub your two stones in a figure eight or some other irregular nonlinear pattern then the only mating shape they can find is flat-to-flat. When they are truly flat you should be able to rotate them against each other in any manner and not see light.

Tom

Re: Three surfaces or three stones?

Dan Donaldson

>I bought mine without the lapping plate. They also go out of flat, but it seems to take a lot longer for it to happen, and they still seem to cut fast. I have a 1000 King waterstone and a 1000 Shapton. The Shapton seems to cut faster and stay flat longer. I flatten the Shaptons on the ceramic flattening stone that I have and it seems to work fine. When I am using them, I just rub the stones on the side of the flattener that is grooved. Periodically, I will use the flat back side of the flattening stone and use carborundum powder and do the stones dry. That way, I can put pencil marks across the stone and they wear off rather than wash off so that it is easy to tell when the stone is flat. This works for me, but YMMV.

Makes sense.

Dan Donaldson

>You are right, I also remember that this was for straight edges. I only use two surfaces to flatten, one is the ceramic flattening stone and the other the stone that is being flattened. It seems to work fine.

Hmmm.... The engineer in me wonders if there is a way to prove this mathemagically;-) Probably is, but I don't think I will attempt it.

Except, Dan...

Ted Owen, Pittsburgh

>you'll rarely use a Shapton that coarse. I have a Shapton 120, and you use it only on really beat up beaters or blades that dropped to the floor and got nicked. For most sharpening jobs, if you use Shaptons, you'll normally start around 1000.

So it takes a long time before a coarse Shapton requires flattening.

Best, Ted

Re: Except, Dan...

Tom Williams

>Ted,

You have been more fortunate than I, as I often start back flattening on a Shapton 320 and once had to make a few strokes on the 120 beforehand. Bevels, however, wouldn't need this unless you were making changes in angle.

Tom

Re: Only need two stones

William R. Duffield, on the Cohansey

>I disagree. With only two stones, the only thing you can guarantee is that both surfaces are spherical, one concave, the other convex. With three stones, you can also insure that the radius is infinite.

Re: Only need two stones

Don Thompson - South of Miami

>Do I detect mirror/lens-making experience?

Re: Only need two stones

William R. Duffield, on the Cohansey

>Vicariously, only. I have friends who have built telescopes, and have absorbed some knowledge of techniques for grinding and polishing mirrors.