Grindstone Wear Management

[GIPPER]

I'm faced with sharpening two dozen wood carving and turning chisels of all shapes.  With the first 3 or 4 tools, I found sharpening them with 250 grit, then grading to 1000 grit with each tool was annoying and time consuming.  I wondered how much more wear would occur on the grindstone doing it this way.  So, the question arose, Would it be better to first sharpen all tools with 240 grit, then grade the stone to 1000 grit, then finish the job with each tool?  I wondered how one way or the other affects the wear and tear on the grindstone.  What are your thoughts on this question?  Gipper

[Jeff Farris]

There are two reasons to regrade the grindstone as each tool is sharpened.

First, doing it any any sort of "batch" mode, where several tools are ground at the coarse setting, and then reground at the finer setting would require that the tool be jigged up twice. The chance that the tool is locked in place at exactly the same point is slim to none. Couple that with readjusting the Universal Support twice for each tool, and it isn't hard to see that alignment issues are going to appear.

Secondly, even if you could insure perfect alignment (which you can't), the coarse surface will not remain effective for more than one or two tools before it needs refreshing with the stone grader.

The grading process keeps the stone clean and free-cutting in both modes. Customers who watch me use the system for more than a few tools are always amazed and how often I use the grader. The stone is an amazingly versatile steel cutting device, that can deliver fast cutting or fine finishing, but you as the operator have to tell the stone what you want it to do.

As for stone wear, a full cycle, from fast cutting to fine cutting and back to fast cutting, takes less than one thousandth of an inch from the grindstone diameter. Don't obsess over grading away the stone. You would have to be a very patient person to materially alter the stone dimension with the grader.

[Ken S]

Gipper,

Your post illustrates some common thoughts most of us share (myself included). 

If you have two dozen dull chisels and gouges, this probably did not occur since your last sharpening session last week.  We all want to jump right into the big project.  We want to build the blanket chest or highboy, but spending several hours of practice to become proficient cutting dovetails is not appealing.  Nor is regularly doing touch up sharpening.

Divide your sharpening into smaller units.  For example, try sharpening three or four gouges.  Dress your wheel with the TT-50.  Do your tool set up carefully.  Once you have your gouge fully sharpened, feel the edge.  As you are turning, as soon as you notice the edge being not quite as sharp as this, do a touch up sharpening.

This may seem time consuming.  However, how much time do you want to spend using dull or almost dull tools?

The good side of having two dozen dull tools to sharpen is that by the time you have all of them very sharp, you will be much more proficient, assuming you work smart.  If you do not have the DVD Jeff did on sharpening and using turning tools, you really should get one.  It will jump start your sharpening technique and hone your turning technique, also.

I believe most of us don't like the idea of regrading the stone regularly.  It's the nature of the beast.  If a stone is coarse enough to cut quickly, it won't be fine enough to polish an edge.  Try removing a nick from a chisel with an India stone; it will make regrading the Tormek seem pleasant and very quick.

We worry about wearing out our precious Tormek wheels.  Yet, how often do we jump in our cars to drive just a couple blocks, even though it contributes to shortening the life of the vehicle?

Ron Hock, in his excellent sharpening book, describes using the Tormek as almost "surgical" compared to using a dry grinder.  I think that's a good description.

Try to look at having two dozen tools to sharpen as an opportunity to improve your sharpening skills while restoring two dozen tools, not as a chore.  It could be satisfying.

Ken

[Steve Brown]

Hi Ken,
Good post. BTW, what is a good way to take big nicks off of a chisel? I have tried with the T-7 wheel in the 250 mode, but it seems pretty time consuming. I'm thinking about starting with a dry wheel grinder, but there is something about that idea that puts me off. What do you do?
Steve

[Ken S]

Steve,

I think a nick deserves dressing the wheel with the TT-50 to make sure the wheel is as coarse as possible.

Lie-Nielsen grinds a 30 degree primary bevel on its chisels.  On chisels whih will be struck, that seems like good nick prevention to me, or at least a better defense.

You might ask your carpenter to be a bit more careful, too.

I have found over the years that dry grinding often imparts a nice blue finish on the blade..... Make a mug of coffee and enjoy your Tormek time.

Ken

[Herman Trivilino]

Hi Ken,
Good post. BTW, what is a good way to take big nicks off of a chisel? I have tried with the T-7 wheel in the 250 mode, but it seems pretty time consuming. I'm thinking about starting with a dry wheel grinder, but there is something about that idea that puts me off. What do you do?
Steve

If the nick is pretty deep, I would probably take just a bit of steel off the heel with the dry grinder, being careful to dip the chisel in water often to keep it cool.  I'd move back and forth between the dry grinder and the Tormek, making sure I'm not taking too much off with the dry grinder, and making sure I'm dry grinding at the correct angle.

[Ken S]

Good thought, Herman.

Ken