Question
Does a Tormek really offer a time/cost benefit? I have a six-man shop and we do a lot with hand planes and chisels. Although the planes are tuned constantly, the chisels are not and require a lot of time to bring them back up to par.
Forum Responses
(WOODnetWORK Forum)
From contributor F:
I believe the water bath slow grind machines do a great job but are slow compared to high speed grinders. It's not for everyone, but there are grinding/honing methodologies that rely on hand/eye skill instead of specialty jigs and equipment. These methods are employed by serious hand tool using craftsmen that are bent on getting it sharp and getting back to work.
For instance, at the grinder, the tool rest is not set to a specific angle and the chisel or plane iron set flat on it and slide back and forth. The rest is set to a somewhat shallower angle at a lower height and left alone. Instead of relying on the tool rest for the grinding angle, with the grinder off and the wheel at rest, the chisel is placed against the wheel so that the existing hollow grind is aligned with the wheel surface and will approximately maintain the 25 degree grinding angle.
So with the tip of the chisel in position with its existing hollow grind meshed with the radius on the motionless wheel and the shank of the chisel resting on the outer edge of the tool rest, the chisel is grasped on the shank between the thumb and two fingers of the user's secondary hand while purposely having the index finger of that hand bumped tightly on the bottom edge of the tool rest.
Once this grasp on the chisel shank has been made, it will not be released until the grinding process is completed. This is because the outer edge of the index finger on that hand is your index for placement of the chisel on the wheel again after you remove it to switch the grinder on and also when you momentarily stop grinding in order to quench the chisel in water.
Now with chisel clamped in the secondary hand and removed from the wheel, the grinder is switched on. With your more educated hand, grasp the chisel as close to the tip as possible without getting so close to the wheel as to grind your flesh.
Now, while keeping the tip of the chisel pointed upward, bring your secondary hand to the bottom edge of the outer edge of the tool rest and tightly bump the outside edge of your index finger to that surface. Then slowly pivot the tip of the chisel forward until it contacts the wheel and begin grinding. As long as the finger grip of the secondary hand is not released or shifted, the grinding angle will remain constant when the chisel is removed from the wheel to be quenched or inspected for grinding progress and then brought back to the wheel for further grinding.
The educated hand that is grasping the chisel closest to the tip can be removed at will when not actively grinding. This hand works with the clamp hand to move the chisel side to side on the spinning wheel.
A finer point is that the hand closest to the wheel can be used to feel when the chisel is getting too hot and should be quenched before further grinding.
Lastly, good hand grinding is all about the pressure. You will learn to use a fairly light touch (pressure) while grinding that will remove steel quick enough while not causing heat to quickly build in the tool steel.
Also, all of the above applies to plane irons, spokeshave irons, etc. as well as chisels.
When it comes to honing the freshly ground edge, again, the serious hand tool user has no time or need for training wheels, angle guides or other commercial gadgetry to hone an edge. The bevel is simply placed flat on the stone as the tool or iron is held at that angle only by human hands and rubbed until a burr is evenly formed on the flat back of the tool. Care is taken that the tool is not allowed to rock during this process and cause rounding of the cutting edge.
Use a chisel with a wider bevel to learn. Practice on a piece of glass for a moment. Lock your wrists and hands and rock your upper body to and fro as you hone. Most people have a tendency to hone more than necessary and defeat the side benefit of the hollow grind, which reduces the amount of steel being honed away.
Lastly, there are two separate but equally important planes (surfaces) to any cutting edge. The flat back opposite the bevel must be perfectly flat and polished to have a truly sharp tool. This is easily accomplished with black silicon carbide sand paper glued to a sheet of thick glass(3/8" or thicker) with spray adhesive.
The flat back of the tool is simply held perfectly flat on the sandpaper and rubbed until all millmarks and any pitting have been ground out. The starting grit is determined by the condition of the tool being worked.
I usually go up to 600 grit and even finer if I am ambitious. It should be noted that fortunately this process need only be done once per tool. If the polished surface is never scratched or otherwise damaged it need not be repeatedly polished. The only thing that is done to that surface in future sharpening is a quick rub on the finest grit used in its polishing to remove the burr formed by honing the bevel.
It should be mentioned that glass is used because it is perfectly flat. Stones become less than flat with use and are fine for the short surface of a bevel but not recommended for flattening tool backs.
I agree, a good craftsman doesn't need jigs or guides to maintain a 25 degree angle. Which is not a problem with my journeymen. And inasmuch as they're constantly tuning the planes, it only takes a couple of minutes at the 4000 waterstone or diamond plate to bring them back to a good working order.
My problem is with the chisels: long shank mortise chisels to short shank Stanleys and Japanese. These get abused quite a lot for various reasons, and fortunately not often for hitting a nail. But the sharpening of the chisels is left to apprentices, and this is time-consuming; teaching them to stand correctly in order to maintain a 90 degree edge while stroking, maintaining the correct angle, etc, etc. It's a one-day process, and it drives me crazy. (I've my own set of chisels that nobody touches and I only need a couple of minutes at the waterstones to bring them back up. But I can't seem to bring my workers to deal with the chisels as they do with the planes.) I have to live with this. I've tried to establish a schedule where the chisels are sharpened daily, but this has been difficult given our workload and other chores seem more pressing.
So, I come back to my question: would a Tormek, with all of its jigs and guides, hasten this process? And, if a Tormek is the way to go, how much advantage would I achieve with a 10" wheel as opposed to the 8" (i.e. the hollow grind)?
Or should I put my foot down and schedule daily chisel sharpening? As I write this, it seems this is what I should do. Why spend $600 when it's always better for workers to develop and maintain good work habits? I think I've answered my question.
Although it seems safer to for you and your men to always hone and not grind, I think you are missing out. It is easier and faster to hone a hollow ground edge instead of a flat bevel especially after you learn not to hone more than necessary. You can get several honings per grind. Your tooling will have a sharper and longer lasting edge from a honed hollow grind. Flat grinds tend to be rounded due to the increased honing time and they are also harder to feel "flat on the stone" than a hollow grind which only touches at the tip and heel.
Take a chance and try my method with the shop beater chisel and a cheap high speed grinder. Always grind any nicks out first by grinding into the wheel in such a way that the grind is 90 degrees to the flat back of the tool or plane iron. This is faster and less likely to burn an edge than trying to remove nicks will grinding a 25 degree bevel.
For most work, a chisel and even most plane irons need not be perfectly square… just close. The edge does not even need to be perfectly straight off the grinder (think wide tools, narrow wheel) because the surface of the honing stones will bring it straight the second the wire edge is all the way across.
The bit about holding the blade in the index finger - and indexing with such finger - is particularly helpful since it repositions the blade at the same angle after inspections/cooling. This grinding advice also works for short run tooling grinding where a cutter or two need to be made to make several feet of an otherwise unobtainable molding. Fast and economical, this type of ability and know how is what has built profitable shops for centuries, and will go a long way even in today's shops.
While I have used methods as contributor F describes for 35 years, recently I have added a 1750 rpm grinder fitted with two cardboard discs as shown in the Razor Sharp Edgemaking System on the recommendation of a carver. These are used after grinding. This is undoubtedly the fastest way to get perfectly sharp edges on everything from chisels to carving tools to even shaper tooling (HSS). Safe and easy, mirror finish edges come out in less than a minute, and you can easily shave a forearm - our shop test for hand tool sharpness.
I believe that most garden variety bench grinders turn about 3600 RPM. There are adjustable speed grinders on the market but I cannot give you any advice on what speed to use if you had one. My non-adjustable speed grinder turns 3500 RPM and works great.
When it comes to wheels, the grey ones that come stock on most grinders will work once you learn the right touch and grinding pressure and when the tool is hot enough to be quenched.
A better choice for tool steel are the white colored wheels and the ruby colored wheels. There are even some blue colored wheels that are better for tool steel than the grey. I like and use the ruby colored ones although I can grind a chisel on any wheel that happens to be mounted on a grinder.
60 grit is a good grit choice for grinding tool steel. The grit need not be super fine for hollow grinding...this is the rough side of sharpening. We will polish the tip of the chisel when we hone.
I purposely am not getting into all the technical aspects of grinding wheels such as the bond type, etc., and just saying white, ruby, etc. because I want to get across that this process is simple and you don't have to have "the kind" to do this.
When I started responding to this post I took it for granted that you had some sort of high speed bench grinder in your shop. If not you should get one if simply for the reason they come in very handy for so much more than just grinding a chisel.
A few last tips:
Learn on a chisel that is narrower than your wheel. Work your way up to wider tools - they require more skill to keep the tip straight and square. Don't stress if the tip is a little crooked or if there are facets in your grind - the honing process will fix that.
Don't burn your steel. It is better to leave a tiny flat to hone out than to burn the steel. You will need to burn a chisel or two to learn. When you burn one, just grind the tip at 90 degrees to the back to remove the burned steel and start over.
I have noticed that when I grind steel in a cold shop in the morning, say 50 degrees or less, I often have no need to quench the steel.
Lastly, the whole registration process that I spoke of in my first post is most comfortable when the front edge of the tool rest is fairly thin, say about 1/4" or so thick and somewhat wider than the wheel. If your tool rest has a long vertical plane that your index finger will bump against, simply attach a piece of 1/4" material to it that overhangs the front edge by 1/2" or so.
