I recently attanded a dovetail class, where the instructor lambasted my use of microbevels on my chisels. I have used a 30deg microbevel for years and he was adament that you do not need a microbevel with the various jigs and power tools to sharpen your edge tools to a consistent bevel.
I let the instructor take one of my chisels to sharpen it on his power tool sharpen contraption. He sharpened it to a flat 25deg bevel. Razor sharp sure; however, when I started to chop out the waste for a halfblind dovetails in oak the edge just crumbled. Now I know if the chisel had a 30deg bevel it probably would not have crumbled.
My question is simple, are microbevels worthwhile or should I just sharpen the chisel to a consistent 30deg across the entire bevel?
Replies
Personally I don't put a microbevel on. I find it easier to sharpen when there's a larger flat.
I also don't use any jigs, or blade holders so for me just a flat face works best.
I also have no idea what angle my chisels are sharpened at. And they are all probably a little different.
When I notice they are getting a little dull I sharpen them quick, about 10 seconds on the stone and there good to go again.
But I belive whatever works best for you is what you should do! And if the instructors edge crumbled while chopping oak, he needs to learn to sharpen!
I usually hand sharpen my tools. usually just a touch up on the 8000 waterstone or leather strop works for me. If the edge gets too jacked up I will take it to the slow speed grinder and work from there to 8000 grit. My last 6-12 strokes on the highest grit stone to create a 30deg microbevel.
But like you said, if it ain't broke don't fix it.
Barry
A couple of things come to mind:
1. Any instructor who "lambasts" an adult student need not be taken seriously about anything.
2. I usually microbevel, but not consistently. It seems to help the longevity of the edge.
3. 25º is pretty shallow. My expensive Lie-Nielsen chisels will roll over if less than 30º.
4. Everyone works differently and expects different results. Do whatever your experience dictates.
Hi Barry
A note about terminology. I thik that you mean "secondary bevel". This denotes a bevel that is added to the primary bevel and at a higher angle. A microbevel is simply the size of a bevel. You can creat a microbevel on a hollow ground face that lies coplanar with the face.
On chisels, I avoid any secondary bevel that is at a different angle to the primary bevel. I plan to hollow grind the bevel face, then freehand hone. A coplanar face is easier to balance on the sharpening medium.
However the main reason for maintaining a coplanar face is that a chisel with a secondary bevel makes it much harder to use when paring bevel down. Bevel down is a common option when paring fine detail or when having limited space. When bevel down the bevel face becomes the blade "back" for registration. A secondary bevel reduces this area making registration difficult.
If you want to strengthen a chisel bevel with a higher secondary bevel, then this is goes to limit the chisel's use to one side of the blade. For example, my mortice chisels have a primary bevel of 20 degrees and a secondary bevel of 35 degrees. This is OK since they are only to be used for chopping in the vertical. You could get away with this in a chisel for chopping dovetails, but then they would again really only be good for this type of task and not for paring bevel down.
Regards from Perth
Derek
Derek, As always an informative response. I'm curious as to how often in your woodowrking you find occassion to pare bevel down? And in what particular applications? I have rarely done so, but perhaps I'm missing the boat as far as a better way to do certain things? Thanks.
Samson,
Two thoughts come to mind. When you want to get to an area where there's something in the way, like molding when it's between you and an area/spot that you want to pare beyond it. You want to keep it flat but the molding will be in the way when using the flat back of the chisel.
Another is when you want better control of how the chisel wants to dig into the workpiece. Probably a bad analogy but kinda like ridin the bevel and tilting the blade into the workpiece.
These are two instances where it has worked for me, your mileage may vary.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I'm curious as to how often in your woodowrking you find occassion to pare bevel down? And in what particular applications?
Hi Samson
I'm sure that you would surprise yourself in this regard. I cannot imagine only working from one side of the blade.
Here is a picture of paring the end of a dado ..
View Image
(Don't ask where I get all these pictures - sometimes I'm amazed to find them on my harddrive. I think my wife puts them there. This one was from an article I wrote on the LV Small Plow plane).
Regards from Perth
Derek
Derek,
I use chisels a lot, and often do carving. I'm sure you'll be relieved to know that I do not readily limit myself when trying to get a woodworking task done to one side of any blade or otherwise. ;-)
As far as paring the end of a dado, were I making one like this, I'm pretty sure I would think to use the chisel bevel down as you demonstrate, but I tend to make dados with my router (plane or electric), so haven't run into the situation you kindly show in your picture.
As Bob mentions, I tend to think bevel down when paring long grain that would invite my chisel deeper than I'm aiming for - bevel down allows one to come back up much more easily - as one often does wih a drawknife.
Anyway, thanks again.
Bevel down in my shop -- roughing/cutting a rabbetroughing/cutting a groove starting/cutting a mortiseflushing a pegremoving waste from a concave curve of an apron, leg, etcremoving dovetail waste after an initial vertical chop, pare bevel down toward that stop cut.I'm sure there are many more, I'd have to stop myself and make a note when I find I am using a chisel bevel down, but it is quite often.Edited 7/29/2008 2:08 pm ET by deanjEdited 7/29/2008 2:09 pm ET by deanj
Edited 7/29/2008 2:15 pm ET by deanj
roughing/cutting a rabbet
I'd use my 78, my 'lectric router, or potentially my 10.
roughing/cutting a groove
I'd use my router plane or my 248 plow. - or the 'lectric router or dado stack in the TS.
starting/cutting a mortise
I'd use my mortising machine or my Isles mortising chisels.
flushing a peg
I'd use my flush cut saw and block plane - maybe a chisel, but bevel up works fine for me.
removing waste from a concave curve of an apron, leg, etc
I'd tend to use my gouges and carving tools for interior curve work.
removing dovetail waste after an initial vertical chop, pare bevel down toward that stop cut.
works fine bevel up for me.
I'm sure there are many more, I'd have to stop myself and make a note when I find I am using a chisel bevel down, but it is quite often.
Don't get me wrong, I appreciate hearing about other folks methods of work, and certainly appreciate you answering my question. That said, I thought I'd say how I typically perform these applications for the sake of discussion. Thanks.
"flushing a pegI'd use my flush cut saw and block plane - maybe a chisel, but bevel up works fine for me"
---------Okay, fair enough though I'd cut out that block plane and think twice about the risk of saw scratches...and still use a chisel bevel down- one tool does all.
So how are you going to shape raised pegs??? (four or six angled flats).Philip Marcou
You make a good point about the faceted raised peg. I would indeed use a chisel bevel down to do that. I've never built anything with such pegs, but if I did, that's no doubt the best way to make the facets.
As far as saw scratches when flush cutting, I never have had any. If someone gets them, it's either their saw or their technique.
Mind you bevel down to flush up pegs is not a bad way to do it at all. I must say, getting them flush, no matter how you do it, is a job that takes only a minute. It is not a big part of woodworking nor particularly challenging to do well no matter how accomplished.
philip,
though I'd cut out that block plane and think twice about the risk of saw scratches
Perhaps you know this but Lee Valley makes a flush cut saw with teeth on one side that I have and it works very well flush cutting plugs, etc. - doesn't leave any scratches. Sometimes a wee bit of sanding and Bob's your uncle.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Hi Bob,
Is it a left flush or right flush ? (;)
I do know of this saw but the hidden point I was making is that of a dozen tools to do a simple job.
Philip Marcou
Hi philip,
Ahhh, so true about the many ways to skin the cat. In many cases it seems the best solution is to use what one has/is comfortable using to get it done.
As to this micro-bevel thang would you think we should establish a nomenclature so folks don't trip over the various uses of the terminology?
How about secondary bevel vs primary bevel where the secondary bevel size is micro in relation to the primary bevel. Back bevel would be a secondary bevel established on the back side of the blade.
To me this whole business of tertiary bevels is a bit confusing, seems like a lot of extra work and I question the return on investment, especially in bevel down applications. It would seem one could achieve the same results with but just a primary bevel at the proper angle.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
THere is a nominclature - the problem is not everyone subscribed to it.
A primary bevel is the main bevel a tool is ground to.
A secondary bevel is a smaller bevel, ground on top of the primary bevel.
A micro-bevel is a minuscule secondary bevel of a few thousands width that is easily removed by honing the primary bevel. see: http://www.antiquetools.com/sharp for more informationJoel
http://www.toolsforworkingwood.com
joel,
I get all that but I'm thinking that the main reason for a secondary bevel is to preserve the edge. Could I also take it to mean that one would only want a secondary bevel for coarse work/chopping?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
A secondary bevel is mostly used as a shortcut to honing - strengthens the edge, but also reduces penetration. A micro-bevel can strengthen an edge without significantly altering penetration as long as the width if the microbevel is less than the thickness of the pared shaving. But has no effect on performance (other than strengthening the edge) on plane irons or chopping.Joel
http://www.toolsforworkingwood.com
Joel, the confusion will continue despite your best efforts to simplify the nomenclature.
Those angles you gave names to as primary and secondary bevels are also known amongst certain ranks of woodworkers, ie, me and a whole load of other British English speakers as the grinding angle and the honing angle.
I don't know what a micro-bevel is, except to assume that whoever was doing the sharpening messed up on the job a bit and mistakenly cocked the chisel or plane iron a bit higher as they did the last bit of their honing, ha, ha.
Lastly, I've never really had a clue what angle I use for grinding, nor for honing. I just hold the tool at either the grindstone or the bench stone at angles that feel right. It's as unscientific as that, except I do know what angle to hold the tool at to get a good grind and a good edge. Slainte.
Richard Jones Furniture
Edited 7/31/2008 10:52 am by SgianDubh
Richard,
If you hone as I do where the tool is flat on the stone after being ground your grinding angle is the same as your primary bevel angle. Actually the grinding angle is always the same as your primary bevel angle. If you lift up the tool to hone you are creating a secondary bevel. I was taught to use microbevel to improve edge longevity, and improve performance. I stopped using them for years, then about 10 years ago I went back to them. I means I can have a really low primary bevel and get much better paring control -without having my edges roll over or chip. when honing I always go pack to the primary bevel.
Joel
http://www.toolsforworkingwood.com
joel, I tried the one angle grinding and honing thing too for about three years or more. I went back to two distinct angles.
I've never bothered with this micro-bevel thing that some people use. It all seems a bit finicky when you start doing things like that.
I'm just a sharp'n'go type myself. I've always kept the whole sharpening thing dead simple and completely freehand, and very quick to boot. I just can't get very excited about the idea of complicating what I find is no more than a basic and rudimentary task.
I'm one of those that tends to think that if you can't sharpen your standard planes and chisels quickly and simply without a lot of fiffing and faffing around, then woodworking will probably never be either accomplished or profitable or even, for the amateur, enjoyable or fun; although I suspect some people just find sharpening as an end goal itself enjoyable. Slainte.Richard Jones Furniture
I sharpen freehand too. And I fully agree with you and the need for simplicity and speed. I find I get better performance with a microbevel, and it's easy to do free hand, and since I don't let it grow I can go years without having to regrind - although I like a hollow just to save time. joelJoel
http://www.toolsforworkingwood.com
It's clear from your post that your twenty-plus year career in woodworking has been a figement of your imagination. It would be impossible to use handplanes whose irons were worked up in such a haphazard manner.
(musically) Life is but a dream....
Ha, ha. Slainte.Richard Jones Furniture
Bob,
Joelm has just confirmed the , er, correct terminology. Possibly, if one wanted to leave no doubts about what one is waffling about one could refer to the primary angle as the "grinding angle" and the secondary as the honing angle.
Meanwhile, just to keep the nasal scribes to the grindstone I just have to say that I believe those who hone at the same angle as the grinding angle have must have unnatural desires....
Philip Marcou
Derek,
You pretty much summed up my sharpening technique. I have heard the "microbevel" called a secondary, and I pretty much can see them used interchangebly.
I never really thought about the reaction of the cutting edge when conducting bevel-down paring. You do bring up a good point. With the bevel down with a secondary bevel the the cutting edge is not flush with the wood as intended. Thanks for the info.
I think the use of that chisel answered your question in a way. Now, had he put a flat 30 degree bevel the edge would have held the same as your 30 degree microbevel. But, especially when chopping dovatail waste, that larger higher bevel angle reduces the amount of penetration. Add into that the modern thick chisels and I'd lean toward a low primary bevel with a small higher angle bevel for edge retention. As others have pointed out, you may not like this configuration if you pare bevel down and ride the bevel. Give it a try, you can still pare bevel down with chisels set up like that, so your milage may vary.
I grind and hone bench chisels and bench plane irons at 25* with no microbevels/secondaries/"ruler trick" back bevels, nothing, zip, nada. Simplicity itself - an unobstructed ramp with a sharp intersection. Geometry you can believe in.
Some of the old literature refers to a chisel or plane iron "cutting sweeter" with no secondary bevel. They were right.
Edited 7/29/2008 3:51 pm ET by BossCrunk
Barry,
That instructor -- is he still alive? or did you do him a favor and put him out of his misery. One of the other respondents already said that such behavior is NOT acceptable on the part of an instructor.
Have fun.
Have the courage of your convictions.
Mel
Measure your output in smiles per board foot.
There are differences in tool steel. There is always a compromise between hardness, brittleness and sharpenability. English Sheffield steel chisels, in particular, won't hold an edge at low angles. The primary bevel is ground at 22.5° +- from the factory but you are expected to sharpen the edge with a secondary bevel of 30° for softwoods and 35° for hardwoods. A micro bevel doesn't add enough edge strength since they are practically invisible and done with light passes on a very fine stone. A secondary bevel may show about 1/16".
If you buy Robert Sorby's large set of bench chisels, they come with these instructions. Their smaller sets and individual chisels don't come with the instructions. Most of the English chisels are similar. It's quite amazing that the edge will fold with one cut at 22.5° but you can work all day at 30°. There is nothing about this on their website.
I bought some Sorby's a while ago, sharpened them at 22.5° and had the edge fold with hardly a tap. I wrote to the supplier and Sorby. They both explained the need for a secondary bevel at a stubbier angle. As soon as I sharpened them at 33° (a compromise), the difference was like night and day. I don't think I have ever seen this discussed. Had I known, I would have bought different chisels, since I prefer 22.5° for paring work. 30° +- gives a much choppier or coarse cut when shaving crossgrain. I sent this picture with my complaint and received a prompt response.
Beat it to fit / Paint it to match
Barry,
The main reason to use a microbevel (I use the term interchangably with secondary bevel) is to save time. Instead of resharpening the entire face, you need only hone the very tip.
Chris @ www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
"My question is simple, are microbevels worthwhile or should I just sharpen the chisel to a consistent 30deg across the entire bevel?"
I think that MICROBEVELS for chisels are not worthwhile or necessary. Anyway after a few honings (especially when there is a full moon). Anyway, that microbevel soon becomes a SECONDARY bevel especially when a honing guide is used, otherwise the tendency is to hone an increasingly steep angle .....
I would consider a Microbevel on a plane blade-but probably not for too long.
I have always followed the instructions from certain chisel makers of note- " grind at 25 degrees and hone at 30 degrees". Seems sensible to me since 30 degrees gives reasonable edge strength and you can do many honings at 30 degrees before that Secondary bevel gets too wide . (It gets Too Wide wide when it takes too long to hone....)
But then again, those maestroes who don't use honing guides are good at saying they are good at freehand honing because they just raise the angle a bit every time, thus conserving steel and ensuring that the secondary bevel doesn't get too wide -and saving steel ofcourse (;).
Barry - The other posters to this thread have many good points, and I think you can see that there would be disagreement over whether to use a small secondary bevel for edge retention within a narrowly-defined bevel angle.
That is, I don't think anyone would advise a 14 degree grinding angle on a chisel (though it would be supremely sharp and cut like a hot knife through butter in an extremely soft wood like Eastern white pine), nor would anyone advise a 50 degree grinding angle or secondary bevel because it would cut like pounding a steel bolt into a wood block (i.e., it wouldn't cut, though it's unlikely you could roll this edge over).
I thought I might add a (very simplified) discussion of the physics of the cutting edge. When you're driving a chisel into continuous wood (such as in the middle of a board), the apparent sharpness of the blade is due to both the degree to which the bevel and back of the chisel meet at a sharp point, and the angle of the entire bevel. A chisel with a very shallow overall bevel (say, 20 degrees) will cut much deeper with a mallet tap than one with a 45 degree overall bevel, assuming the mallet taps are delivered with equal force.
The reason for this is that when driving the chisel into contiguous face grain, the wood fibers are not only cut at the edge, they also have to be crushed and moved out of the way of the chisel as it penetrates the board. A shallower chisel angle means that the the wood does not have to be compressed on the bevel side of the chisel to the same degree as one with a steeper angle.
When paring a thin slice of end grain, however (such as paring down to a line on a set of dovetails), the overall angle of the bevel doesn't play as big a role as the bevel angle at the very tip of the chisel. The reason is that there is "somewhere for the wood to go", and the thin end-grain slice offers very little resistance to being crushed and fractured by the wide bevel of the chisel. In this case, the perceived sharpness of the chisel sensitively depends on how well the edge is dressed and at what angle a microbevel is honed at.
This is why I keep two sets of chisels - one for paring by hand only, and one prepared and intended for general (and coarse) chopping. The paring chisels are hollow ground at 25 degrees, and are honed with no microbevel so that the edge is also about 25 degrees. For the general joinery chisels, I hollow grind these at the same 25 degree bevel, but also hone a microbevel at about 35 degrees for edge toughness.
I too have 2 sets of chisels, one for paring the other for "general" work. I tend to grab the latter more so the paring set. When I get home I will try what you and others have suggested to set the secondary bevel to 30+ deg. I should mention that I do hollow grind my chisels on the slow-speed grinder before sharpening and my last step is stropping on an old leather belt glued to a board (I'm Cheap) with some compound. It works well for me.
It's shocking to see how many responses I have receieved from my original question. And no, I did not bump the ol' guy off when he questioned my use of a secondary bevel. But I will say the redneck/military in me wanted to grab the guy by the throat. Being a self taught woodworker and that dovetail class being my first class was a shocker none the less. I highly doubt I will be taking a class with that cat again.
Barry
Camden, NC
Jeff, I took PB to be making a joke to the effect that many of us take ourselves a bit too seriously as far as swearing by some numbers like 25 degrees (not 24 and not 26) in prepping our tools - magazine articles can also give that impression many times. Anyone who has used a plane or chisel pretty quickly figures out that this stuff is much more forgiving than the accuracy some folks spout as absolutely required for decent work. But maybe I misunderstood?
View Image
Edited 7/31/2008 12:42 pm ET by Samson
I took it not as a joke, but as someone who sadly and mistakenly believes these chisel and plane iron bevels actually need to be measured to be effective. Of the 50 or 100 cutting edges on planes, chisels, etc..... in my shop, you probably couldn't find 2 that match exactly. When they're dull, I remove them from service, rub them on my chosen sharpening medium until sharp, and then get back to work.
So, I guess that I agree with RJ that the exact angle is meaningless. What matters is that the angle is large enough to hold up under the forces applied by working the edge against wood.
If I took it wrong, then PB can set me straight. I'll chalk it up to internet ignorance (not being able to see the smile on his face as he's speaking.........)apologize, and delete my post. If he's serious, then so am I.
BTW, I know you know all this gar-bage already. And, incidentally, I find it easier to get the tool sharper...faster....by using a secondary bevel.
Jethro the unknowing
I use secondary bevels too. I like a strop with honing compound when I need a touch up in the middle of something, and no doubt that leaves a micro-bevel too as the leather gives and I do it freehand. Horrors!!
Coincidentally, when I do use my bench chisels bevel down, registration of the bevel face seems rather unimportant - it's such a slight face after all. The registration, such as it might be, would hardly be much different it seems whether on a secondary bevel or a primary one - but maybe that extra 1/4 inch would be a big deal in some circumstances?
I took PanBroil's post as humour Jeff, as I suspect he, or perhaps she, picked up the hint of wry humor in my post -- there was a ha, ha in their to indicate that.
I appreciate your efforts to support me, but I really don't think there was any malice in PanBroil's post.
I know I'm big enough, ugly enough and even perhaps mean enough and knowledgeable enough about woodworking subjects to back up anything I choose say in woodworking forums. And if I do make errors, as we all do from time to time, I generally admit to them pretty quickly. Slainte.
Richard Jones Furniture
It's been a long summer without hockey......I guess I was just looking for a little preseason scuffle.
Sorry to all.........I'll go back in the closet.
Jeff,
My wife calls it somestimers in my case. Somestimes I think and somestimes I............. well you know the rest.
:-)
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Jeff,
Was it Rodney Dangerfield who went to the arena to see a fight, and a hockey game broke out?
Ray
Ray
I used to have a bumper sticker on an old work truck of mine that said that very thing. You can take the hockey player out of the fight, but you can't take the fight out of the hockey player.
ha ha
Jeff
Perhaps you should change your forum name to "MostLikelyToGetFragged," " 'RoidRage," or better yet, "ExponentiallyObtuse." If I happened to be as stupid as you appear to be (or as amped up on Dynabol, or both), I would be damned if I'd use my real name.
It was a joke that apparently everybody else got but you didn't.
Relax Jeff. Take a deep breath.
Edited 7/31/2008 4:56 pm ET by PanBroil
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