Woodworking Tool Sharpness Levels

[SteveG]

I'm a hobbyist woodworker. I use a Tormek to grind my plane/chisel blades, but not for sharpening them. For that I use stones, either with a Veritas jig or freehand (the hollow grind makes freehand sharpening of plane blades, and most chisels, easy). When I first got my PT-50A, I measured after each sharpening, and found I could usually hit BESS 100. I usually polish to 8000, sometimes finer (I have up-to 30000 stones), and I usually strop with CrOx (and sometimes dull my edge in that process; I'm not very good at it). BESS 150 or less is easily achievable with my methods, BESS 100 usually achievable; BESS 150 is usually good enough, though for shooting I can tell the difference with BESS 100 giving me much nicer results. I grind at 25 degrees, and sharpen at 25-30, depending on the blade (sometimes higher, but I've never measured any of those).

[Ken S]

Steve,

Very thoughtful post.

Irwin (formerly Marples) 3/4” Blue Chip chisels are my go to learning tools with the Tormek. They are bench chisel length, have properly ground non radiused backs, and are inexpensive. I have around a dozen, all 3/4”. Having several allows me to compare different stages of grinding and different grinding wheels side by side.

I did some testing of 80 and 180 grit CBN wheels with my Tormek. As part of the testing, I ground chisels (standard 25° bevel) with both CBN wheels. I am recalling the BESS numbers from memory. The 80 grit wheel used alone produced a reading just under 500. The 180 grit wheel produced a reading of around 400. Both edges looked gnarly, or in knife people terms, had very adequate toothiness.

I wanted to see how much I could lower the BESS readings by going directly to the leather honing wheel charged with Tormek's standard PA-70 honing compound. After around a minute, I was surprised with BESS readings around 130. Not bad for a cheap and dirty two step. The bevels cleaned up considerably with the long honing time, but still would not win any smooth polish awards.

As a control, I also sharpened an identical using the traditional three step method with the Tormek SG-250 aluminum oxide wheel. Again, relying on memory (not terribly scientific at my age), this more careful method yielded a BESS reading of 100. The CBN wheels win hands down for reshaping turning tools. I much prefer the traditional three step Tormek method for sharpening chisels and plane irons.

I know your combination method of using the Tormek for grinding and stones for honing is popular and effective. I understand the logic behind it. Please do not be offended by my next questions. is your preference based on side by side comparison after becoming very proficient with the stone grader and leather honing wheel? Or are you basing your preference on the higher grit numbers of the water stones (8000 to 30,000 compared with 6000 for the honing compound)? 

I realize that the stone grader can seem tedious and the leather honing wheel problematic. They were for me for several years until I made an intense effort to understand them. (another plus for having some sharpening/practicing chisels) I am not defending Tormek; I am just curious. I am well aware that the answer may be "It depends", factoring in the application and species of wood.

Ken

[SteveG]

Ken,

Your question is valid, and I suspect your skills on the Tormek surpass mine, otherwise I might just do everything there. Note that I've never measured the sharpness coming off the Tormek, but the reason I don't use it for full sharpening isn't that, rather it's that if I use the leather wheel on chisels I inevitably "unflatten" the back, and I want my chisels to be perfectly flat, especially when paring. And the reason I don't use it for plane blades is that I sharpen them the way I sharpen chisels! (IOW, for no particularly good reason.)

I do use the Tormek leather wheel for stropping my woodcarving tools, usually with good results. But for those I don't use it for grinding, since I want a flat or convex edge; concave edges don't pull out of cuts with the same control.

And finally, for turning tools, I use only the tormek, unless I need to do some serious reprofiling, where I find the Tormek just too slow on HSS (I only have the stock/standard wheel).

As far as the Tormek grit, I think it normally behaves much finer than the 1000 they advertise. Mine doesn't seem to stay coarse for very long, and when it's smooth I think it produces a finer scratch pattern than my 1000 grit stones. And the leather wheel with the Tormek paste also seems finer than the 3 micron they advertise, so I have no need to refine past that. But my eyes aren't so good, and I often misjudge the angle and dub the edge, so it's not my go-to tool of choice for things like knives.

Don't worry about offending me (which you didn't), I'm here to learn, and critical questions are always best for that. If I'm doing something stupid, I don't mind if someone tells me (well, I do mind, but I still prefer it to remaining stupid).

I've reread your last paragraph, thinking about how it applies to me, and realized that when I'm sharpening woodworking tools, my goal is to get back to woodworking, so while my skill with the Tormek is lacking, my current method is good enough and quick enough that I wouldn't be motivated to make that intense effort that you have. But when I sharpen knives, my goal is to understand the steel, the geometry, and to further my skills. I don't sharpen knives on the Tormek, but with that nudge from you I might give it a shot, and see what I can learn. Thanks.

Steve

[Ken S]

Steve,

One of my father's favorite sayings was "We can be bold in doing something if we are first humble in learning how to do it". You and I seem to share that positive humility.

Like most tools, I think the Tormek is better suited for some tasks than others. For me, it does an adequate job of flattening and polishing chisel backs for most purposes. I used it with the old Buck chisel because it has a nice feel and it has a belly which needed to be corrected. For a fine paring chisel I would use either a meticulously flattened water stone or glass and abrasive paper. I would also use these methods with a new or new to me chisel. Flattening seems a function not quite in the area where Tormek excels. It can handle the laborious part of flattening. For light flattening, I do not feel it is the ideal choice.

Just because the Tormek can do many sharpening tasks very well does not mean that it can do every sharpening task at that level. It is also certainly not the only sharpening tool, and not the only tool I use. Like most of us, I am a creature of habit. I used the same photographic film and developer for over thirty years. I tried to keep an open mind, but I feel the years using the same combination gave me a deeper working knowledge. That knowledge let me focus on making images (getting back to woodworking).

Based on my study of older editions of the Tormek handbook, I believe the stone grader concept began when Tormek switched from the natural grinding wheels mined on a Swedish island to the present manmade grinding wheels. The manmade aluminum oxide wheels are coarser and cut faster. However, the finish was not as fine as the natural, slower cutting wheels. I suspect many users missed that finer finish. Tormek has always included simplicity in its philosophy. The stone grader offers an almost complete substitute for a second, finer wheel.

I agree with you about the honing compound. It works well, however, I believe the micron designation is as much an educated guess as a precise measurement.

Do not underestimate your knowledge and experience. You have much to share. We have a lot of expertise on this exchange. I certainly do not include myself among the experts, however, each post I read gets me a little closer. I like the polite, sharing environment here. It is conducive to growth.

Keep posting.

Ken

[SteveG]

Ken,

Yes, this is a unique forum, and the only one I post on. Occasionally I want to post something ,or ask questions, on other forums, but since I use the BESS scale for evaluation I don't have a common language in most cases. So, between the good company here, and the measurable point-of-reference, this is quite a find.

For my use of chisels, I found (the hard way) that if the edge is beveled even a few thousandths on the back, it lifts instead of cuts, and avoided the Tormek for them ever since. I love the Tormek, just not for everything, as you've pointed out. Hopefully with experience my exclusions will dwindle.

My understanding of the Tormek honing compound is that it "averages" 3 micron, so my assumption is that there is a reasonable latitude in both larger and finer particles. It's also my understanding, and to the degree I've observed it my experience, that on a leather substrate the particles don't fully project from the substrate, so they tend to behave as finer than their actual size. Either way, for my carving tools, where I notice polish the most, the Tormek leather wheel works great (unless I dub the edge).

Interesting piece of Tormek history, I wasn't aware of that. Makes sense, and obviously a good solution.

I'd like your father - I sadly don't hear many people talk like that nowadays.

Steve

[Mike Brubacher]

Steve and Ken, your comments make this all worthwhile. Thank you.

[Ken S]

I am grateful for an exchange where I can grow from others' experiences and have the opportunity to occasionally add something to the group's knowledge.

Thanks for the opportunity, Mike.

Ken

[Bud]

I'm a guy that knows about 10% of the average member here but I feel comfortable posting. I've got a BESS tester and I don't sharpen a knife without it. It's very helpful to see numbers reported here because it tells me when I'm up to snuff and when I've got a ways to go. I have to give Scott a special shout out here. He practically gave me the recipe for exactly what I want to do with files. It just gave me the confidence to go ahead and do it. When the parts for the wife's ceramic kiln come in I'm going to do it. The conversation is friendly here without a bunch of king size egos weighing in. Great and friendly home I've found here and thanks to all who have welcomed me.

[Ken S]

Bud,

Good post. I think a lot about learning curves. I have become convinced that being exposed to genuine expertise, particularly early on, is the best key to learning. I certainly do not count myself among that group, however, we do have some real deal experts on this exchange. You will be surprised with how much your knowledge will grow and with how much you can add to the conversation. We bring many backgrounds to this group. I believe this diversity adds to the scope of the topics.

Enjoy being part of the group.

Ken

[Ken S]

Bud,

A second thought and another key to learning. I may be known as the guy who wastes his precious Tormek grinding wheel by truing it too often. I do that intentionally and, for the record, I don't think it wears down my grinding wheel any more than ignoring it. Several times in the past I noticed my sharpening was not going well. An initial very light truing cut told the tale. The light cut was only touching the high spots. I continued making very light cuts (about half a number on the microadjust) until the first cut which ground consistently. I don't really know how much of a problem a slightly untrue wheel is. I do know that by developing the habit of consistently keeping my wheel true, I can check one more thing off my list of potential trouble sources.

My point is if we control what we can with good work habits, we can cut down the number of gremlins.

Ken