Waterstones Not Cutting

[Dan McCallum]

I've had good success with Norton waterstones for the past few years. I use a Lee Valley truing stone to keep them flat, and I flatten the truing stone as required on 150 grit sandpaper on a granite surface plate.

Recently I have noticed a dramatic reduction in the cutting abilities of the stones, the truing stone, and the sandpaper. ie, my whole system. It has become very difficult to flatten the Norton stones on the truing stone, it's like the truing stone is no longer cutting, hardly any swarf is formed even when I rub them together for much longer than I used to have to. (I recently purchased a new truing stone but it made no difference.) Similarly when I am sharpening a blade on one of the waterstones, it seems to take much longer than it used to. Flattening the truing stone itself is also a problem, but not as bad as the others.

I wonder if they have become contaminated with something that is interfering with the cutting action, or if they have become burnished, or some other problem?

Dan

[Joel Goodman]

Not sure if I have any explanation but have you tried scubbing the stones and then using fresh sandpaper on a flat surface to explose a fresh cutting surface-- without using the truing stone?

[george wilson]

Use a diamond bench stone to rub your water stones on.

[Mike Holbrook]

I have never used the Norton stones but, some stones are prone to loading with contaminates acquired from the work. I know these contaminates can be hard to remove. The process of removing this material may also remove a sizable amount of the stone.

I just switched to stones I acquired from Stuart Tierney at Tools From Japan for this and another reason. My other stones were having a very hard time cutting the new harder steels and HSS. There are quite a few new & old steels out there that are much easier to work with stones designed for their specific qualities. The Sigma Power and Sigma Select II stones Stuart sells are working much faster on all the steels I work and they are not loading up on me either. Lee Valley offers three of the Select II stones as their premium stones, Stuart carries the full range of these stones. I have used Shaptons and they are nice but I don't think they compare to the Select IIs or the Sigma Power stones. I like the fact that the Sigma stones are thicker, less delicate and much less prone to loading.

Stuart may chime in here, but he stays very busy. might be worth dropping him an email for more info.

[Jim Matthews]

" My other stones were having a very hard time cutting the new harder steels and HSS." MH

Mike has alluded to my suspicion - are you cutting a new piece of steel, or the same tools as when the system worked quickly?
I have a set of Blue Spruce chisels that take ages to sharpen. (But they hold that edge a long time, too.)

[Mike Brady]

The solution to your problem is not buying another set of stones. You simply need to find out what is wrong with your technique in using your existing Norton stones, which should be perfectly adequate. I have no idea what the "Lee Valley truing stone" is, but set that aside for now and concentrate on getting your stones flat and clean. Since you have a reference plate, just put a wet sheet of 220 grit wet/dry paper on the granite and lap the faces of your stones, rinsing the paper well between each stone. That will get you to zero. Norton stones will cut well until they finally get so thin that they crumble.

Sharpen a iron from a tool that you have gotten sharp before. Flatten the stones again as above and try an iron that is giving you problems. It could be that you have acquired a new tool that is made from tougher steel than you are used to, although I have many edge tools and not one has ever failed to sharpen well using !000-through 8000 grit Norton. If the truing stone is the one from Norton with the diagonal channels cut into it, throw it away. A continous diamond media hone is a far better flattening answer, as David Weaver pointed out.

[Stuart Tierney]

Umm, contamination?

Any oil will affect the cutting rate of a waterstone, but it won't stop them. The amount of oil needs to be significant though, and I think you'd notice it by a 'wet' appearance when the stones should be dry. A few drops of oil generally isn't noticeable in my experience in a soaking stone like the Nortons are.

Harder steel than normal as has been mentioned is a possibility. It may well be that even though you might not have a new tool, there may be a hard spot in the tool that's affecting the effectiveness of the stones.

But, and I'll veil what I think my suspicion is here otherwise I'll get yelled at, what I'd like for you to try is one of two things.

#1, take one of the now slow stones and find a piece of nice, flat concrete. Rub the stone on it using a lot of water. Clean off the stone with water (some dishsoap is ok too) and your hand and try some steel on it. If there's a difference, then there's something in that information.

#2, find a piece of glass or steel that's relatively flat and beg/borrow/steal some abrasive grit. Any size is fine, #120 is ideal. Wet down the flat glass/steel and put a teaspoon of grit on the flat 'thing' and rub the wet stone on this. Make sure you work up a goodly amount of mud. Wash the stone off and try it. Again, an improvement is significant. If you can't find some abrasive grit (sandblasting grit is a good source), then fine sand will also work, just not as well.

Above all else, keep any of your existing flattening gear well away from your stones for the time being, and use one of these alternative methods to try and get a fresh, clean surface on the stone. Method #2 is ideal especially with proper abrasive grit.

Not looking for a flat stone here, just a fresh surface. It doesn't matter if the stone looks like a fish bowl, so long as the working surface is fresh and clean by different method to the one you're currently using.

In short, I wouldn't be at all surprised if the flattening stone is contaminated, and it's transferring the contaminant to the proper stones.

If you leave your stones in water permanently, then there could be algae in the stones, which can plug things up as well. Completely drying them out and washing with soapy water may bring them back again, but normally flora and fauna in the stones isn't a death sentence, it just makes them slimy to the touch until the working surface is refreshed.


That's about all I got. I've got a strong suspicion about what the problem is, but won't say anything else until I hear back whether the problem is corrected or not by the above methods.

Good luck, and one way or another the stones can be restored but you may need to change how you go about things...

Stu.

[Mike Holbrook]

I imagine there is a way to restore the stones you have. I have my doubts about repairing major problems with sand paper in what I would consider a reasonable amount of time though. I spent quite a while studying the solutions that my fellow posters on these pages have come up with for this increasingly difficult task. There are an increasing number of steels on the market that are much harder to sharpen. The whole spectrum of solutions to truing stones contaminated or worn by the tougher new steels was daunting.

I determined that I wanted to be able to sharpen much faster and true stones up faster too, so I started looking at diamond devises to do tougher jobs and repair stones. Many people on these pages use the diamond devices for these purposes. Diamond devises are certainly not cheap though and I determined I would need multiple devices to do the work. The cost in time and money to beef up my old stone system was high enough for me to look at alternatives to buying multiple diamond devices. For me, the cost of better stones for the steels I work was close enough to buying diamond devices to consider that alternative. As steels have improved and or become more complex in recent year so have the stones designed to sharpen/repair those steels. I decided I got more bang for my money by getting better stones vs investing in diamond devices. I have a few specialized abrasive grits that I use to true stones if/when I need. Stones that do not load and cut faster tend to need much less maintenance.

Sharpening is a crucial part of using fine edged tools and I determined that I wanted the process to be as quick and pleasurable as possible. I don't regret the money I spent. I wish I had done it sooner.

[David Weaver]

As far as I can tell, the norton flattening stone is just a ceramic stone around 90 grit or so (maybe i'm off about the grit, but judging the way mine behaved several years ago when I took it to a shapton 220, I'd say they were just about made of the same thing).

I would start with the flattener, run it across 60 grit wet and dry paper until the surface is clean, then soak the nortons and hit them with the freshened flattening stone until they also have a good cutting surface, and avoid two things:
* allowing any of the stones to load significantly by not using enough water
* allowing the surface to get contaminated with anything that isn't water or water with a very light amount of dish soap

I'd guess the flattening stone is plugged.

The system itself works fine (the norton stones with the flattening stone), but the flattening stone itself needs flattened when new, and possibly every several dozen times you use it on a norton stone - and you need to make sure you use enough water to keep it flushed when you flatten with it.

[Dan McCallum]

Thanks to everyone for the suggestions!

FYI I am not sharpening any 'new' steel, the blade that I was working on that caused me to post this problem originally was an old Stanley blade, I am sure it is pre-1950's. So nothing exotic, steel-wise.

I notice that looking at truing stones' surface carefully in a raking light, they are quite obviously glazed looking in places.

The truing stones and the Norton stones seem to flatten OK when I use them on 150 grit sandpaper on a granite surface plate, although it still takes way too long.

(As an aside, I was taught to not flatten the Norton stones directly on sandpaper, as it causes them to glaze and cut less effectively, better to use the truing stone to keep them flat, then flatten it with sandpaper. I am sure not everyone does it this way, which is perfectly OK of course, but this is the way I do it)

I think I will try something along the lines of what Stu has suggested, clean all surfaces of everything on concrete in an effort to get rid of any contaminants.

Dan