30-35 Degrees, or 20-25 Degrees?

Good morning Dave...

Scott Burr in Ben Lomond CA

>(Said in my best H.A.L. voice;)

The Hock blades come at 25 so when you hone them at 30 deg. you�re removing a minor amount metal.

As for ebay and flea market planes, well just about anything can happen here. From inexperienced users, old carpenters going by hand on a job site, quick and dirty sharping (so to speak). Only God knows with some I've seen.

So that being said, I grind my blades to 25 deg. and hone to 30 deg.

2004: A Woodworking Odyssey

Dave (Arlington, VA)

>Hi Scott -

No question this has been a journey for me. I'm no Odysseus, but Wood Central/Hand Tools is my Argo, ya'll are my fellow wood-lovin', hand tool-totin' Argonauts -- and actually making a respectable piece of furniture is my Golden Fleece.

I appreciate your thoughts on my flea-market blades and their bevel angles - and you're sharing of your blade sharpening habits. You're probably right, but there are no secondary or micro-bevels on these babies - so they were just straight 20-25 degree bevels.

Thanks again for your post.

Regard -

Dave

L. Lee Response...

Rob Lee

>Hi Dave -

I took the liberty of firing your question off to LL...

His verbatim reply follows!

Cheers -

Rob

First, you need at least 5 degrees of relief on a blade or else it will tend to ride up on the sprung-back fibers that are released behind the cutting edge. This is another generalization. If you are cutting with a very sharp blade, you get very little fiber spring back; you might be able to get away with 3 degrees relief with a light cut. If you are using a blade in desperate need of resharpening, you might need ten degrees. All varies with species being planed as well.

Regarding chatter, a 45 degree bed invites it much more than a 20 or 12 1/2 degree bed because the force triangle is so different. Unless you are accustomed to keeping your cap-iron close to the blade tip and well tightened, you can get some substantial chatter at 45 degrees, much more that you get at lower angles which is why you usually have a dual purpose cap-iron/lever cap on planes with low bed angles. If you have a low grind angle, the forces can distort the blade tip more easily than with a high grind angle. The blade tip stiffness varies in relation with the angle. Higher angle, stiffer tip; lower angle - springier tip.

But a well-placed, well-tensioned cap-iron can defeat much bad-tip geometry. I suspect you are finding a lot of blades around with 25 degree grind angles because manufacturers usually grind them at that angle and users follow the manufacturers lead. Manufacturers usually grind all chisel tips at 25 degrees also but that is not always the correct angle for them in many uses either.

I wrote that sharpening book for two reasons. The first was to avoid answering a seemingly endless stream of sharpening questions, which it did except for the insistently curious (read "Dave" here), and because I wanted people to understand why edges are shaped differently for different tools and different uses. I wanted you all to be masters of your own destiny. Well, OK, that last sentence was a bit trumped up but most of what lead up to it was serious. Use your own judgment and experience as your guide in all this and you may not always be right but you will learn a lot quickly and fret about it all less.

Leonard Lee

Re: 2004: A Woodworking Odyssey

Adam Cherubini, NJ

>Dave,

I think you are on to something. I've noticed the exact same thing in both plane irons and chisels, but especially the former.

I'm in no way chastising anyone here when I say its pure arrogance to assume what was done in the past was done in ignorance. In my experience the ignorance is all mine. The frequency with which I see these low bevel angles causes me to think it was intentional.

You may find on closer inspection that the cutting edge is sharp, but dubbed over somewhat. I suspect and have for some time (though I lack any real data) that the dished stones used created a rounded sort of micro bevel.

Todd Hughes has eluded to this in the past. I'm not sure if this is his belief, or reflects his own examination of period tools. One wonders how, before the days of scary sharp, workers could hone blades sufficiently to do the work we know they did.

Adam

Wow, Rob. Thanks to you and your Dad!

Dave (Arlington, VA)

>Hi Rob -

This was much more than I had ever expected. It was awfully thoughtful and gracious of you to check with your Dad - and for your Dad to reply. I had carefully read his section on bench plane blade sharpening and I think I understand his explanation (both here in his post and in the book - which I highly recommend to anyone interested in hand tools! It is probably my most used woodworking reference book, and invaluable for those new to this craft).

In fact, he had persuaded me - that's why I was grinding blades to 30 degrees last night. But then I began to wonder why the five or six people who'd owned some of my various bench planes before me not been privy to your Dad's observations and reasoning (other than the obvious - i.e. they'd not read his book), and instead ground/honed their blades to shallower angles. And that is what had led to my question.

Thank you for your post and please convey my thanks to your Dad to his reply.

Regards -

Dave

Williamsburg

Dave (Arlington, VA)

>Hi Adam -

Thanks for your post. As it turns out I'm headed down to Colonial Williamsburg in a couple of weeks for some weekend fun with the family. This ALWAYS means a visit to the cabinetmakers shop. It's the one thing that Dad gets to do.

This time I'm going armed with a couple of questions. First, I'm curious what the bevel angle is on their bench irons. I know they use woodies - but I'm still curious. I'm pretty sure they don't whip out an angle guage - like I do :-)

Second, I want to know how they flatten their oil stones.

Third, I want to know if they flatten the back of their blades -- and, if so, how much.

Fourth, I want to know what pattern or motion they use across the stone when flattening the backs of their blades.

Fifth, I would love it if I could persuade them to demonstrate some freehand sharpening.

Whew. I just realized, that's alot to cover. I may have to con (I mean, pursuade) my family to make two visits to the Hay shop this time - an "AM" stop and a "PM stop." I may also have to wear a disguise in the afternoon so they won't recognize me the second time through.

On the issue of shallower bevel angles on in-the-wild blades, one thought I've had is: freehand sharpening. I have played with freehand sharpening, and it seems to me that it's easier to lock your wrists if the bevel angle is shallower (i.e. the back of the blade is closer to the stone). Just a thought from one who's very ignorant of such matters.

Thanks for your post!

Regards -

Dave

Re: Williamsburg

Dave Anderson Chester, NH

>Hi Dave- The guys at the Hay cabinet shop will be more than happy to answer all of your questions. They love to talk with real woodworkers, it's a great change of pace from the sometimes inane questions they get from the general public.

Re: Williamsburg

William Claspy in Cleveland

>Dave-

A couple of weeks ago, I visited CW with my two young daughters. We spent a couple of days, and my two gals were kind enough to allow three visits to the Hay shop. For the third visit, I made sure they had some goodies to occupy their time in the "front" of the shop (where they have examples of completed work) so I could ask questions at will.

The guys at the shop are very helpful and more than willing to entertain questions. They will, however, just keep talking, and take the topic wherever they want it to go. Not that there is anything wrong with that! Just plan on plenty of time. They also trade off who is doing the talking. So if you go back, chances are there will be someone else for you to bore, er, entertain with questions. :-)

On one of my visits, I was delighted to find Mack Headley in the "front" room, and nearly no one else in the shop. We had a very nice talk about apprenticeships, joinery, plane making and wood species. I found that I got brain lock though. Seriously. It's like when I've been to Powell's Books in Portland- so many books that I find myself unable to think of any *one* book that I'd like. Even browsing is impossible. At CW, I didn't even remember Mack's name until we were eating dinner later that day. "Star struck" maybe? Dunno. So maybe write down your questions so you don't forget 'em.

What a fabulous place to visit though- for the Hay shop and the rest of the experience as well. We were there two full days and still didn't see everything. My girls are well trained though- even before I saw it, they spotted the original of a music stand I am currently making (nearly done) in the ball room of the Governor's Palace. So *that* is where Roy got the inspiration!

Have a great trip. I can tell you that I'm looking forward to our next visit.

Bill

Re: Wow, Rob. Thanks to you and your Dad!

Don Thompson - South of Miami

>One thing that "stuck" from LL's great book was his recommendation (and I paraphrase here) that one should use the shallowest angle possible that will not result in edge failure with the tool and medium combination for the task at hand.

The flip side, of course, is that one should increase the bevel angle if edge failure occurs, until it ceases.

Thanks for the encouragement!

Dave (Arlington, VA)

>Hi Dave -

I was thinking of you yesterday. I finally got around to de-barking and splitting one of the two sections of black locust I've had drying in my shop for the last year or so. Although it still checked and split (in spite of having both ends sealed), I'm hoping to be able to get a number a decent sized quartersawn sections out of it.

This is where my thinking of you comes in: eventually I want to take these (what will be) QS Black Locust blanks and turn them into a bowsaw. That piece of artwork you crafted and call a bowsaw still lingers in my head and fires my imagination. That in turns, brings us to the present and your post above - Congrats on the inauguration of Chester Tool Works. I'm sure it - and you - will be a success. But my main hope is that you have fun at it.

Again, thanks for the encouragement on asking questions at the Hay Shop. I'm looking forward to it.

Regards -

Dave

A wonderful time!

Dave (Arlington, VA)

>Hi William -

Glad to hear about your recent, positive experience at CW. We were down there last this past February and had one of the best family weekends we've ever had. Our four kids (and their Dad) got recruited into the Colonial militia and were drilled in flintlock firearms on the grounds of the Arsenal; my daughter got to sit side-saddle on a ladies saddle in the saddle shop - to only mention a few of the fun and interesting things we did.

It's a great place for families. And the Hay Shop is a great place for woodworkers. I lingered there last time and listening an extended discussion on veneering, and wood selection. But this time I have an "agenda." Thank for the thought on writing down my questions. Probably a good idea.

Thanks for sharing your experience. It was fun to read.

Regards -

Dave

Re: Williamsburg

Adam Cherubini, NJ

>Dave,

Please report back. If its not too much trouble, it would be helpful if you photographed any demos regarding this subject.

You might also want to ferret out, as politely as possible, what they do, how they do it, and how often they do it in regards to this subject. You may find that tools are prepped in a back shop somewhere. We shouldn't assume they do this type of work in front of the public.

Currently, my home shop is Pennsbury's backshop. We have a few modern stones and a sandstone grinder that doesn't work well at all. All sharpening is currently performed off site.

Last time a tool was sharpened on site, our own Jeremy Osner did it! He made the mistake of coming for a visit and was instantly pressed into service. You should be careful about how much they know about you or you could end up with a similar fate!

I would wear bandaids on many of my fingers and one across my forehead, if I were you. You might also try dropping things the whole time you are speaking with the interpreters there. That might throw them off the sent.

Have a nice trip,

Adam

Good reminder

Dave (Arlington, VA)

>Hi Don -

Thanks for the reminder. All the recent discussion of chisels and edge failure serve as a useful reminder that different steels (including plane blades) respond differently to the stress of shearing or severing wood fibers. I've got a fair range of blades from modern Hocks to SW laminate blades, and from different makers from Stanley, to Sargeant, to Dunlop, to Millers Falls.

But for me - as a relative novice - I'm looking for a rule of thumb knowing that as I gain experience (and specific knowledge of my particular tools) I'll be either modifying or creating exceptions to the rule.

Still, one of Mr. Lees points - if I have understood him correctly - is that while bevel up tools (such as block planes, low angle bench planes, and most applications of bench, paring and butt chisels) have to trade off between edge retention and effective cutting angle, in a bench plane you (almost) only have to worry about edge retention because it's the bedding angle (not the bevel angle) that establishes the cutting angle for the bench plane (assuming no back bevel).

I appreciate your post and the reminder of one of Mr. Lee's main points.

Regards -

Dave

Wow!

Tony - Memphis

>Having Mack to yourself for a while is indeed a rare treat! I took a class from him at Marc Adams and a big part of the class for me was him talking furniture/history while we "worked." He rattled off more that week than I'll ever learn. There were a couple of lads in the class that were quite up to speed on such matters, so the conversation was quite good. Mack is a real treasure to the sport. We asked him about a book, and he kinda shrugged it off. Not sure he realizes how much he knows! I had met him at Williamsburg several years before and he was the one that pointed me towards Dover books for reprints of the Chippendale etc. books. Can't wait to go back to Williamsburg someday.

Tony

Re: Williamsburg

Dave (Arlington, VA)

>Hi Adam -

I enjoy following your posts so I remembered that your shop is at Pennsbury - and that's way cool!

I'll do my best to report back. Not sure what I can do on the pic front as we currently lack a digital camera.

On sharpening in the shop, you may well be right, but I do recall that on my first visit to the Hay Shop they were truing and flattening the sole on a wooden jointer. It wasn't really a demonstration - at least for the public. It appeared that someone was showing a colleague (an apprentice?) how to do it - including the use of small winding sticks. Very Way Cool. Wish I knew then what I know now - but then again I'm sure I'll be saying that two years from now.

No need to worry about then enlisting me in the shop. With all that I need to learn, after a few minutes I'm sure they would (graciously) show me the door.

Thanks for your post.

Regards -

Dave

Re: Williamsburg

Tony - Memphis

>I posted below about a class with Mack, but his sharpening technique was interesting...his sharpening stones look like they have been around since the original Hay shop!!! The thing he taught us that I remember was to push the tool down until you saw the oil get squished from under the bevel and then start sharpening. Please report back to us with what you learn! Mack is a quite a pc guy, maybe we could get him to sign on sometime. I have some drawings he had done in CAD of some cabriole legs.

Tony

Re: Williamsburg

Dave (Arlington, VA)

>Hi Tony -

Interesting observation about the squishing oil. I wonder it the same would apply to waterstones?

Also a good idea to ask Mack on to one of Ellis' Chats. I was on for a while with the one with Roy Underhill. Great fun and very informative.

Thanks for your post.

Regards -

Dave

Re: Williamsburg

Verne in Northeast NJ

>Went with the family the first week of April. Try to spend more than one day at CW. We were really rushing around, plus it was a big school vacation week so it was really crowded.

Spent far too little time in the cabinetmaker's shop. Really interesting. Didn't get much time to chat because I had to meet up with the family and there were LOTS of people coming thru. I don't know the names of the interpreters I talked to, but they were nice guys.

In both the cabinetmaker's shop and the wheelwright's shop they had C&W bench planes and hollows and rounds. All the interpreters I spoke with raved about them.

I hope to submit some pictures soon.

Re: Good reminder

Lyn J. Mangiameli

>"Still, one of Mr. Lees points - if I have understood him correctly - is that while bevel up tools (such as block planes, low angle bench planes, and most applications of bench, paring and butt chisels) have to trade off between edge retention and effective cutting angle, in a bench plane you (almost) only have to worry about edge retention because it's the bedding angle (not the bevel angle) that establishes the cutting angle for the bench plane (assuming no back bevel)."

Practically, edge retention is an issue with both styles of planes, the difference is that bevel up planes with their lower bedding angles (usually 12, but sometimes 18 degrees) make possible lower effective cutting angles than are possible with the typical bevel down plane. As normally delivered, a bevel up plane will be prepared with a primary bevel angle of 25 to 30 degrees giving an effective cutting angle of 37 to 42 degrees (and so you may also not that nominally low angle planes are really not that much more low angle than their common bevel up counterparts). That 25 to 30 degree bevel angle on the bevel up plane blade will have essentially the same edge retention as a bevel down plane as they are typically configured.

So yes, there is a trade off between edge retention and effective cutting angle for a given steel, the practical differences in the two plane types is moot. Where this becomes more of an issue is with chisels.

Indeed for the same effective cutting angles usually used, the bevel up plane will typically have slightly higher blade bevel angles (e.g.,12 bed plus 33 degree bevel to get a 45 degree effective cutting angle, versus typically a 25 to 30 degree relief bevel angle used with a 45 degree bedded, and thus effective cutting angle, plane.) Is it consequential, most likely not; but it certainly isn't a cause for additional mental consideration or "worry."

The big difference between the plane types, short of using back bevels, is that with the bevel up plane you have an easy means to achieve alternate effective cutting angles, while with the bevel down planes you do not. I personally would not consider this a worry, but a feature. With a typical bevel up plane I have the practical choice of achieving an effective cutting angle of anywhere from 32 to 65 degrees (lower and the edge retention is inadequate, higher and it is too difficult to sharpen and to push the plane). With a bevel down plane I have at most one choice of alternative frog to change bevel angle (with considerably greater hassle, expense and down time) or with back bevels I have a wider range of choices but am limited by the relatively high bedding angle to effective cutting angles from 45 to approximately 65 degrees.

As most know, I have more than my fair share of both types of planes, and like and use both. The issues discussed above are only one set of considerations when choosing between them for a given task.

Re: Williamsburg *LINK*

joel

>It does - you also get a solid clunk feeling when the bevel is flat down. - I was demoing free hand sharpening all weekend at LI wood show and once you get the hang of it it's pretty simple.

If you want to see step by step photos of the process (using oilstones but it's the same technique) see the link below. It was written by my mentor and he only teaches free hand sharpening. It's actually the first lesson in his class.


Maurice Fraser's Sharpening Lesson

A little what I think.....

Todd Hughes

>Many years ago when i was just starting to get into blacksmithing I went down to Williamsburg and watched the 'smiths there working making nails. When they got the rod down to a certain lentgh they would just forge weld another section on. I stood there with my mouth open in awe as I had tried everything in an attempt to forge weld somthing with no luck. Read this and that book, tried all kinds of "Special " fluxes and could no more do it then i could fly by flapping my arms.So I asked the smith what the seceret was to sucesseful forge welding. Maybe he had a long day answearing stupid questions or maybe just his underware was tight I don't know but he just answeared " Just got to know how to do it and then do it" and that was it. On the long way home I sure felt cheated. I wanted to hear about some special ingrediant he had in his flux or some other inside info and here he just told me I had to know how to do it and then do it. When I got home I got to thinking about this and figured I would take his advise and just do it.I "Knew" how to do it but I didn't KNOW how to do it if you get what I mean. I got a big bucket of old horse shoes and started trying to weld them together. I'm a bigger slow head then most i know and it took me more then a couple buckets of shoes but then one day I forge welded one together that i couldn't break apart.Once i knew how to do it it was as easy as anything. I think what held me back was looking for that "Special" way to do it, the magic way to make it easy or thinking I would be able to do it if i only could do it the way that guy in the book did using that flux he sold.

I think alot of people are like I was esp. when it comes to sharpening. They are looking for that "Magic" system whether it is some special expensive water stones, jigs or perfectly flat stones etc. that they think will replace thier just doing it.I think some people just like to spend hours sharpening a plane iron because they think they should and they think the seceret to sharpening a tool IS spending hours on it when in reality it isn't.I also think some people strive to hard for perfection when it can really be a flaw. I use a couple stones I got at the flea market, have no idea what grit they are past "fine and a little corser" They are sort of flat but I certainly never did anything to them. I can sharpen a blade in about a min. or so with them so that it will easly shave the hair off your arm. I don't say this to give anyone the impression I am anything great. I'm Not ! I say it to show if a slow head like me can do it anybody can. I am sure you guys that use fancy waterstones or make sharpening a plane blade an hours long ritual can get them sharper but do you really need to? and is the extra effert worth it? I think tradtionaly the answear was probably no.....Todd

Re: A little what I think.....

Dennis

>Well for a slow head your not wrong IMO. One just needs to "do it" to understand. Now i understand lot of folks want to take the trade to the moon but its not required. How sharp is sharp and what bevel,all a lot of hype ,just get the job done and move on.

Dennis

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Re: A little what I think.....

joel

>In a nutshell what you are saying is that there is no substitute for practice and skill development. I agree wholeheartedly. There is also no substitute for real instruction by teachers who understand how to distill processes into steps and to explain it in a clear manner. THe problem of course with trial and error is that it is mostly error and takes time.

Good equipment certainly makes life a lot easier but it's not essentile.

Re: A little what I think.....

Dennis

>As usual your right on with your comments Joel,and i wish years ago i would have had what we have today the people to show us how things are done.

Dennis , who is thinking about all the times he learned life's hard knocks

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