Flattening waterstones

[Izzy Camire]

Hay Everyone,
I just realized my Norton stones are no longer flat and they need to be flattened. I have the flattening stone. My question is on the amount of water needed to flush the grit away. I am thinking the best way to do this would be in a small plastic tub. Put in a couple inches of water and do the flattening in the water. Does this sound reasonable? Any input would be welcome.
Izzy

[Phillip Mitchell]

I don't know how other folks do it, but I leave my stones flat on the bench/table/etc and take the flattening/lapping plate to it. Just douse it with water enough to keep is lubricated, just like you would with sharpening something that spanned the full width of the stone. I tend to rub the lapping plate over the stone in a figure 8 pattern to make sure I'm getting coverage on the entire stone. I normally rub in figure 8s for a little while (10-20 seconds), check my progress, wash the stone off clean and repeat as necessary.

I also put a slight chamfer on the edges of the stone so I don't slice myself when working close to the edges. Pretty straightforward really.

[Nicholas Lawrence]

It does not take a ton of water. I use sandpaper when I need to flatten, and an occasional splash is enough (for 1000 and 8000 anyway).

[Steve Tripp]

I used to drown my waterstones whenever I used or flattened them. Then I realized I got the same or better results by being a little stingy with the water. When I'm flattening I'll just get the sandpaper wet enough to stick to my flat surface. Works pretty well.

[Mike Henderson]

The Norton flattening stone has to be flattened on a fairly regular basis or it will transfer its shape to the working stones. Generally, the flattening stone will become convex which will cause your working stone to be concave.

I found that out the hard way.

A better way to flatten your working stones is with a diamond plate.

Mike

[After all, if you have to flatten the flattening stone, why not use whatever you're going to use to flatten it on your working stones?]

[Izzy Camire]

Glad I asked this question. Lots of good info. Thanks to everyone who responded.

[Patrick Chase]

Glad I asked this question. Lots of good info. Thanks to everyone who responded.

Sorry to jump in late, but I'd suggest learning how to use either loose SiC grit (cheap) or sandpaper (not so cheap) on a flat surface. You're going to have to do that no matter what to keep your "flattening stone" (which is actually just a fairly dishing-prone coarse-grit waterstone) flat.

[Prashun Patel]

If Mike Henderson has you thinking about a replacement, I have an Eze lap coarse 2x6" diamond plate ($38ish on AMZN). David Weaver recommended it to me and it has worked fine and has stayed flat.

Like others, I take the plate to the stone. Brian Holcombe has taught me to wipe the stone clean with a paper towel, spritz a little water, rub the plate on it. After completion I just spritz the plate and stone with water to loosen the grit, and wipe with a paper towel. This removes 95% of the grit. Any minor residual can be rinsed at the sink.

[Allen Hunt]

Check out this article by Chris Schwartz. Good information here I think.

http://www.popularwoodworking.com/woodworking-blogs/chris-schwarz-blog/dmt-introduces-its-dia-flat-plate

[george wilson]

AT LAST,a subject that has NEVER been discussed!!!:):):)

Again,I warn you all to NOT clog up your sink and pipes with stone slurry. It won't EVER go away!

[Patrick Chase]

AT LAST,a subject that has NEVER been discussed!!!:):):)

Again,I warn you all to NOT clog up your sink and pipes with stone slurry. It won't EVER go away!

Out of curiosity do you see a difference between classic clay-based stones and either ceramic or resinoid ones in that regard?

After the first time I saw you make that comment I pulled and checked the trap in my shop sink - no waterstone slurry, but then again I've never used a clay-based stone. I'd sent the equivalent of ~2 standard sized ceramic stones an a smaller amount of resinoid through it by that time. The resinoid ones shouldn't resolidify at all (at least not without a lot of heat/pressure, and even then only for thermoplastic resins as opposed to thermosets), and I *think* the same should hold for ceramics.

EDIT: As should be clear from the fact that I pulled my trap, I take your remarks very seriously. I'm just curious to understand the context in this case.

[Warren West]

[After all, if you have to flatten the flattening stone, why not use whatever you're going to use to flatten it on your working stones?] I took it one step further than that. I started actually sharpening with Diamond and go to ceramic or arkansas if I need a finer edge than 1000 grit.

When I did have waterstones I flattened them with a diamond plate held under a trickle of water outside from a hose. What kills diamond plates is the swarf from the waterstone grinding away the Nickel. The water gets rid of the waterstone swarf nicely.

[Tom M King]

340108340109I use Atoma film on a granite surface plate in a sink for Sigma stones. I'm not worried if it clogs up the trap, other than maybe losing that much of the stones, which I don't see happening. Those stones don't lose much anyway, like the Waterstones of old. This setup lasted about a year until we moved on. I replaced the old metal trap with a plastic one when we left anyway. The drain for the sink in the shop exits the wall behind the sink, and drops right into an Azalea bush.

I just included the picture of the other side of the sink in case anyone was interested who hadn't seen it. The sink to the left holds a 9x12 granite surface plate (less than 30 bucks on sale from Woodcraft. To the left is a 140 grit Atoma diamond sheet, and to the right is a 400. Between the two diamond sheets is where the sharpening takes place on a rubber stone holder base. The rubber holder stays in place just fine without bothering to tighten. Lapping takes place in a few strokes on the Diamond Lapping Film on the granite surface plate on the counter. The whole process takes a few minutes from whatever state the edge needs, to final polish.

The whole process takes place under a light stream of warm, running water. I use the sides of the stones for the back, lower edges of chisels and irons. If I didn't have a sink to use Waterstones in, I'd use the oil stones. Oil stones will do as good of a job, but just a Lot slower, but then there's less of a mess than using Waterstones anywhere but in a sink. No buckets, or recycled dirty water for me.

The Norton stones were my first water stones. The 4000 and 8000 flatten just fine on a surface plate with a good 80 grit wet-or-dry sandpaper, but the 1000 will eat sandpaper too fast. I used old window panes and carborundum (silicon carbide) grit for the 1000 stone. What takes 10 strokes on the Sigma stones takes 50 on the Norton stones.

[Steve Beadle]

I wonder if I have been flattening my waterstones correctly. Before starting a sharpening session I flatten them DRY on sandpaper affixed to a plate glass base. Of course, when flattening during a sharpening session, I either rub the wet stones together until they stick, or rub them on a wetted diamond "stone". Anything wrong with the way I do it?

[Luke Dupont]

I wonder if I have been flattening my waterstones correctly. Before starting a sharpening session I flatten them DRY on sandpaper affixed to a plate glass base. Of course, when flattening during a sharpening session, I either rub the wet stones together until they stick, or rub them on a wetted diamond "stone". Anything wrong with the way I do it?

Dry is fine. It's a lot easier to flatten them dry actually. I read something to this affect somewhere, tried it, and my (limited) experience verifies the claim. Granted, I rarely use waterstones so take that all with a grain of salt.

[Gene Davis]

I use the Veritas stone pond, glass top lapping plate with stick-on wear sheets, and silicon carbide grit plus water. Seems to work OK.

Have a pair of King stones, one 4000 and the other 8000. I go face to face with them and it keeps them pretty flat.

[Robert Engel]

The Norton flattening stone has to be flattened on a fairly regular basis or it will transfer its shape to the working stones. Generally, the flattening stone will become convex which will cause your working stone to be concave.

I found that out the hard way.

A better way to flatten your working stones is with a diamond plate.

Mike

[After all, if you have to flatten the flattening stone, why not use whatever you're going to use to flatten it on your working stones?]This is correct!

I don't use the flattening stone anymore, either, just a coarse diamond plate like you.

[Stanley Covington]

1. Have two stones of the same grit on hand. Use one stone a while until it's face is just a bit out of tolerance, then use the other stone of the same grit until it too is slightly out of tolerance. Wet and rub the two slightly-out-of-tolerance stone's faces together. Cross hatch the faces of both stones with a carpenter's pencil. Rub some more. Check with a straightedge. With practice, your stones will seldom need more flattening than this. This is the most cost effective and time efficient way of maintaining waterstones. If you pay attention, it will also help you see your sharpening tendencies, and show you how best to work your blades on your stones to reduce the amount of time spent flattening stones. Remember, while not entirely unavoidable, material removed while truing a stone's face is wasted money, and the time spent truing a stone, while not entirely unavoidable, is wasted time. Minimize both.

2. For precise flattening, have a piece of thick float glass on hand. Scratch the face up badly with a carborundum stone. Clean carefully with brush and running water. Rub stones on this glass to make them very flat. Clean stones afterwards with a brush and running water.

3. To flatten a stone badly out of tolerance quickly, use a stone a few grits rougher to true the face. 800 grit for 1000 grit. 1000 grit for 2000 grit. Etc.. Keep stones very wet while doing this to flush mud. Scrub with a very stiff brush and running water afterwards to dig out any embedded grit from rougher stone. For finish stones, use nagura as a final step to remove embedded grit. Then flush the surface. Grit contamination is going to happen with this method, so be sure to dig it all out.

4. Some of your stones, especially the rougher ones used to sharpen axes and drawknives, may become badly dished. The best way to true these stones quickly and cheaply is to start with a piece of sloped flat concrete as in a driveway. Be careful to chose a spot that does not have high foot traffic since it will become polished and slippery; consider yourself warned. Use running water from a garden hose to flush the stone. Rub it on the concrete, turning end for end frequently. Check frequently with a straightedge to ensure you don't go too far. Use your stiff brush and running water to remove stone particles. This will remove the high spots, but it will quickly make the stone's face convex if you don't pay attention. Finish up with one of the methods above for more precise truing and to remove the rough scratches.

Diamond plates work well, but they are neither time nor cost effective. I will spare you my opinion of sandpaper.

[Patrick Chase]

I use the Veritas stone pond, glass top lapping plate with stick-on wear sheets, and silicon carbide grit plus water. Seems to work OK.

The glass plate that LV sells with the stone pond is just an 8.5 x 14 1/4" sheet of tempered glass. You can do a little better in terms of flatness with 3/8" untempered float glass, but you're probably into diminishing returns at that point anyway. It's more than good enough for just about everything.

The PSA laminating sheets that LV sells are great. They're 5 -6 mils thick and very durable. Note however that they aren't just "wear" sheets. Soft materials preferentially lap harder ones, and using a plastic laminating sheet on top the the glass to provide a softer surface dramatically speeds up waterstone flattening. In my experience SiC grit on those laminating sheets are second only (and by not that far) to diamond plates. I've tried to find a cheaper substitute for the LV laminating sheets but haven't had much luck so far.