Maintaining Sharpening and Honing Stones

Solid advice on selecting and using water stones and oil stones, and about how to keep them clean and flat. November 16, 2010

Does anyone know of a good way to clean a honing stone? I use a Norton abrasives, synthetic stone for honing chisels and plane irons. I use water as a lubricant and get great results, without an oily mess. The problem is that over time the pores of the stone become filled with the grindings, and the stones surface seems to be glassed. Would paint, or lacquer thinner be suitable to clean the stone? Maybe worked with a fine brass brush? Or would something else work?

Forum Responses
(Furniture Making Forum)
From contributor Z:
I have a Norton waterstone 1000/4000 grit. I have not had a problem with the pores of the stone becoming clogged. The slurry that builds up on the stone should just wipe right off. Even if I forget to clean it off and it sits overnight, I have been able to clean it with just plain water. You can get a flattening plate for your waterstones. Norton sells one on their website. Every so often they should be flattened. This might cure the problem that you are having also.

From contributor U:
Just get yourself a piece of thick (1/4" or more) glass and some 400 grit or so wet-dry sandpaper, and spray it down with some water. Put the sandpaper on the glass and then flatten and resurface the stone. You can also use a piece of granite instead of the glass. The surface just needs to be flat.

From contributor J:
I have a Norton 4000 grit waterstone, too. Norton makes stones not intended to be waterstones, and their use/care is different so you need to be clear about which you have. If you do have waterstones, the most important thing is that they be kept wet while in use, not just sprinkled with water but totally saturated. Store them in a container of water, so you don't have to soak them for 20 minutes before use. If you do this, the glazing is unlikely to be a problem.

From contributor W:
I have a flattening stone I use on my water stones. It is much easier to use than the glass/granite method, in my opinion. I just keep the flattening stone in the five gallon bucket with the water stones. Use a bit of bleach in the bucket to keep organic grungies from growing.

From the original questioner:
Ah yes, the stone is not a water stone. It is designed to be used with oil. I have found that a few drops of water work just as well to lubricate the process, and there is no oily mess. Maybe I will try rinsing it in water, with a brass brush.

From contributor K:
I have a diamond plate with fine grit which I use for flattening my stones. My stones are natural and the diamond is very aggressive at flattening. I only need to do this once every couple years as the natural stones do not dish out as fast as the water stones do.

From the original questioner:
Interesting, does that diamond plate have a brand name? What should I look for in purchasing one?

From contributor R:
You can buy a cheap surface plate from Woodcraft which is just the right size to accept a sheet of wet or dry sandpaper (available at auto body suppliers) or use a glass plate. Wet the surface of the plate, lay the paper on it, the water should be sufficient to stick it down and then lap the stone until it is flat, using water as a lubricant. Soap and water can be used to clean when they become clogged. I would use a light oil when sharpening.

From the original questioner:
Thanks for the tip. I will try the soap and water to clean the stone. The surface is still flat, so I don't think that I need to lap it yet. As far as the lubricating while honing, why is the oil necessary when a few drops of water seem to work well? I just like using water because it is less of a mess.

From contributor K:
No the plates don't have a name. They were purchased eight or ten years ago from Garrett Wade. I like the K-1 kerosene even on the diamond plates. The right viscosity of the lubricant used is for keeping the shavings suspended so not to clog the pours of the stone and I think it works better than any other oil or water. If you have the Norton combination India stone oil works best on this type of material. I have an old black hard Arkansas stone that was my dad's from the 40's and it was so plugged up from neglect that it wouldn't cut anything. Put it on the diamond plate with kerosene and in about five minutes it cut like new. About the soap and water cleanup, I would rather lap flat on the diamond plate than mess with the soap and water. It's just too fast and certain to remove any build up in the stone.

From contributor G:
A good part of the reason that your oil stones are clogging up is that you are using water. The water is unable to suspend the particles of iron worn off the tool by the grinding process. The oil stones are open pored and the water, rather than staying on the top, is sucked down (carrying the swarf) into the surface of the stone clogging the surface. An oilstone, after it is conditioned by its original oiling treatment doesn't absorb more oil but rather rejects it, thus keeping the grindings suspended in the few drops of oil you add each time and wipe off after each use. Oil also, by its nature suspends the swarf better than water.

Waterstones avoid this by having a different structure and also by being used saturated in water to start with. Perhaps soaking your oilstone in water might reduce the suction and delay the clogging? Otherwise Google "How to restore an old oilstone" and just get used to having to do that every little bit to atone for the sin of using the wrong lubricant.

With oil stones, one uses oil. To avoid the oil use a waterstone. I am sure to get disagreement here but I can see no use for either and recommend the diamond stones made by DMT, they are dead flat and stay that way, they are happy with water or oil, and the diamond is the sharpest and hardest (most aggressive equals fastest) thing out there.

From the original questioner:
Thanks for the excellent explanation. This makes a lot of sense. The stone that I have is a Norton combination India stone. What do you recommend that I do to condition it, as you referred to in your response? I guess that once it is "filled" with oil, I should keep it in something other than the cardboard box that it came in. Also what does India, in the name, refer to?

From contributor R:
The India stone is a man made abrasive- aluminum oxide. It is inexpensive, which is its primary advantage. In a medium grit it is very useful as a slip stone for initial honing of carving and turning tools. I used to keep a large 3 x 8 stone which I used for jointing card scrapers because of its hardness and relatively fast cutting action however a surface plate and wet or dry sandpaper is easier yet. I have little use for it when it comes to honing chisels, plane irons etc. If you use a honing guide it would be ok for the primary bevel, but again, sandpaper and a flat plate makes more sense. Personally I hollow grind most tools and freehand hone on water stones. They are quick cutting and easily lapped flat when they get out of shape, although I wouldn’t be without my full range of Arkansas stones.

When it comes to sharpening, it boils down to personal preferences and level of skill, there are far too many jigs, gimmicks and gadgets out there, stick to the basics. Get four pieces of ¼” glass and stick a half sheet of sandpaper to each, 220 to 320 for the primary bevel. 15, 5 and .5 micro fine for the secondary bevel, if you use the PSA which I recommend put a little soapy water on the glass before sticking down so you can press all the bubbles out.

Set the projection to 20 degrees for the primary bevel and grind until the full bevel is clean and straight, then set the projection to the secondary or micro bevel to typically 25 degrees. Hone on the 15, 5 and .5 micron paper. The secondary bevel should be kept small, initially about 1/32”, even with the guide you should take it slow and careful, pay attention, so you get a nice even bevel. Remember to lap the back of the tool as well, which can be done with the tool in the jig.