# What is the best Grinding Stone?



## andy6601 (Aug 23, 2011)

I have been playing around with my hand crank grinder and was putting a new edge on a Miller Falls block plane iron and it took me 1 1/2 hours to remove a knat's rear end worth of steel. I don't know if the iron is really hard or the grinding wheel I have sucks, most likely it is the two combined. I pulled the cheapy grinding wheel that came with my cheapy bench grinder. So my question is what grinding stone do you use in your hand crank grinders and what seems to work the best for you? This was not fun and I still burned one of the ends when I finally got the metal ground away. Oh well…..


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## mtenterprises (Jan 10, 2011)

Have you cleaned and trued up your stone? That would be the only reason I can think of that it would take so long and over heat the metal.
MIKE


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## Loren (May 30, 2008)

For grinding tool steel a white "friable" stone works very
well. The carborundum wheels that come on grinders
when you buy them hold up really well for grinding welds
and garden tools, but they aren't very good for 
neatly grinding tool steel.

Those carborundum stones are very hard and they get 
clogged with metal bits. The soft white stones (Norton)
wear away much easier and because of that they 
don't clog and they also run cooler.


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## andy6601 (Aug 23, 2011)

Loren,
Thanks for the info! I will have to pick up a white stone and give it a try.


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## lwllms (Jun 1, 2009)

I probably make, grind, shape, heat treat and sharpen more plane irons than anyone involved with this forum. I've tried about all the different grinding wheels out there, white, pink, blue, cut-off wheels and everything else I could find. The most effective wheels I've found are the standard gray wheels in the coarsest grit you can find, probably 36 or 24 grit. Keep your grinding wheels well conditioned by dressing with a diamond dresser any time the cutting action slows or begins to generate too much heat.

You didn't say what grit of wheel you have or what technique you're using. Technique is as important as dressing and the type of wheel.


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## andy6601 (Aug 23, 2011)

Lwllms,
My technique is I try not to spin the stone as fast a I can and I spin the wheel so that the wheel is spinning away so sparks shoot up and back. As for a dressing tool I have this plastic thing that looks like a screw driver and it looks like is has a grinding wheel type material inside of it, personally I do not think the thing works very well so I think a am going to by a diamond dresser. Also the grinding wheel I am not sure of the grit I know that it was the courser one of the two. Where can you get a diamond dressing tool? The thing I got was from a big box and the tool selection at those places are starting to become less and less. 
Thanks for the input.


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## lwllms (Jun 1, 2009)

Andy,
I like single point dressers but others prefer diamonds mounted on a rectangular faced dresser. I just buy Grizzly's 3/4 carat dresser for about $11. Don't use a lot of force pushing the dresser into the wheel. Diamonds are like coal and will burn. If you force things, the diamond goes away pretty quickly.

I'd turn the wheel the opposite direction you're going. Make yourself some templates to set the tool rest at the grinding angle. I use 25º for most chisels and plane irons. My templates are about 3/4" wide, 6" long and the same thickness as the tool I'm grinding with a 25º angle on the end. The templates need to be the same thickness as the tool being ground because you're grinding on the tangent of the wheel and the angle will change with each tool's thickness. Use the template to set the tool rest so that the wheel contacts the 25º bevel in the center of the template bevel.

If you're fixing a problem with the tool, first establish the location of the new cutting edge by grinding at 90º to the flat face of the tool. Do this before grinding on the bevel. After the new cutting edge location is established, you can start working on the bevel. Grind the bevel to the point you have a hair-line of the 90º flat left at the cutting edge, don't grind all the way to the new cutting edge. Hone that flat away at about 30º.

Don't force the tool into the wheel, especially as the steel starts getting thin at your new edge location. A properly dressed wheel has a huge number of very sharp little cutting edges on its face. These actually remove material pretty quickly with only light contact of the tool on the wheel but you need to keep fresh abrasive exposed on the wheel so dress when you feel the cut slowing down or more heat being generated.

After you have your tool initially tuned, your grinding will be just to keep the honed bevel at the edge small. Keeping this small will make honing easy and fast. You also need to keep you stones and the flat face of the tool uniformly flat. This allows doing all the work on the flat face of the tool with the coarsest stone you use to correct any wear to the edge on the flat face and subsequent stones are used only to remove the abrasive signatures of previous stones. Remember, your stones are abrasives too and these also need to be kept dressed.

If you keep your honed bevels small and maintain flat on both stones and your tools, honing shouldn't take more than a minute for most tools.


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