Bevel angle on double bevel chisel

[DavidRa]

A recent present was the book Letter Carving in Wood by Chris Pye. As a result I am now also the proud owner of some carving chisels including double bevel straight & fishtail chisels.
I am struggling to get these razor sharp and am looking for advice on the best bevel angle to use. I have tried 35 degrees as I am having to use a mallet but it does not give a clean cut , seems to bruise the wood rather than cut it.
Any word of wisdom from those with more experience would be welcomed.

 

[Jacob]

30º is the default edge angle for most purposes and best to aim for.
But the actual sharpness of the edge is paramount whatever the angle. I'd look at that first.
Carvers tend to have rounded and highly polished bevels, not "double bevels" which is just a sharpening guide for beginners; start at 25º finish at 30º and then polish on a strop.

 

[DavidRa]

Thanks , will start with 30 and examine the edge. Would you out a micro bevel on these of 25?

 

[Jacob]

Thanks , will start with 30 and examine the edge. Would you out a micro bevel on these of 25?

Sellers shows it well. No micro bevels - just one bevel "slightly convex" as he says

 

[DavidRa]

Thanks

 

[Ttrees]

I don't recall much use of a mallet whilst watching Chris Pye's videos,
it was seemingly quite a bit more delicate than say Follansbee's work for example.
I'll bet if you have a re-read of his book, you might have the answer.
It could be amongst mention of "flat gouges" somewhere,
or perhaps mentioned regarding clearence with knuckles.
He does mention folks differ quite a lot regarding geometry,

Perhaps there maybe some online guide if you were to add Norton into your query,
as he helped develop a range of hones.

Sorry not much good to you, perhaps some carvers if any about could advise better.
I don't see many of them about, well not here anyway.
Adrian is doing a wee bit of letter carving on the other place, if you type in the search "Re: Step on it – Part 7 PAENE EFFECTUS"

 

[mudman]

I have his letter carving book and it doesn't go into any detail about sharpening. However, his 'Woodcarving Tools, Materials and Equipment' does and is a great book to have with a wealth of knowledge in it and goes into great detail about sharpening.
You shouldn't need to change the angle on your carving tool bevels, the one established by the manufacturer will be a good compromise and is probably about 25 degrees. You may need to change it to suit the wood you are carving but I would leave it at that.
You definitely do not want a rounded bevel. If you have one, you will find it difficult to maintain the cut as you have to move the chisel up and down to keep the edge on the line you wish to cut. A slight hollow is okay but try to aim for a flat bevel. I was taught on the course I took that a slight secondary bevel could be put on the inside but Chris Pye does not recommend this, which puzzled me.
I found sharpening of gouges one of the most difficult things of all to get right. You shouldn't need to regrind at first, although this will be needed eventually. But honing on a stone of your favourite flavour will be required. The trick is to do this whilst maintaining the flat bevel. Many are able to do it by pushing and pulling on the stone but I found that for me, it was easiest to use a sideways motion whilst rocking the gouge. However, do not move the arms. Keep them locked at your side and use the legs to move the gouge whilst imparting the rolling motion.
Once honed, you should be able to go for a long time by stropping on leather when the edge starts to dull.
Anyway, if you can get hold of Chris' book, that will give you everything you need although I expect there is a lot out in the internet as well these days.

 

[Jacob]

Just had a look in the Pye book. He suggests looking in his other book for full sharpening details and in fact does go into a lot of detail there. Buy another book?
His rule of thumb seems to be 15 to 20 on the cutting side and 5 to 10 small bevel on the inside or topside, giving an effective angle of 20 to 30º. And polish, no scratches.
As a beginner I'd perhaps stick to just 30º and well polished slightly convex bevel, but the other book details do look good.

 

[Jacob]

..... a slight secondary bevel could be put on the inside but Chris Pye does not recommend this.
...

He does, on page 26, but says optional, some don't do this but he prefers to.

 

[Argus]

A topic on carving is a rare beast on this forum and one on letter-carving is even more scarce, so a welcome to DavidRa for raising the subject.

As a carver, the first thing that emerges in this branch of cutting wood is the dreaded issue of sharpening.
By its nature, gouge and twin-bevelled chisels (No: 1 on the Sheffield list) takes the art along an ancient path..... one that does not use jigs.

Chris Pye has also written other books on carving, which describe getting an edge in detail, as we've already seen. He also has a subscription video channel that will, through demonstrations, answer your questions much better than we can here. Worth a few quid to see how it's done. There are a number of very detailed videos on sharpening all the worst shapes, including the Vee tool, which is a new level amusement in its own right.

https://www.chrispye-woodcarving.com/woodcarvingtutorials
I have one of those straight No: 1 chisels that I must have bought over 30 years ago and I honestly cannot remember that last time I used it.
Certainly not for lettering, which I do a lot of recently and when it comes to lettering, a mallet is the last thing you need......... it is all hand-work. Using a mallet is fine for roughing out large baulks of timber to shape, but detail is all done by hand.

Next, you said that the chisel just bruises the wood. From that we assume that the edge of your tool may need 'improvement', but you don't mention what type of wood you have. Put simply, some wood carve and take detail well - Lime, Poplar or Jelutong ( if you can still get it) whilst other types do not. Hardness and curly grain is something that you do not need, certainly when you are just starting out, and most definitely not for basic lettering.

However, when you get further into wood carving, you will read all about the rules, then the shapes and angles to the cutting edges that you must have - and the ones that you must never have., such as rounded corners, rounded heels to the bevels, secondary bevels...... then you'll start to break them all when you find a reason to do so.

Good luck.......

 

[D_W]

However, when you get further into wood carving, you will read all about the rules, then the shapes and angles to the cutting edges that you must have - and the ones that you must never have., such as rounded corners, rounded heels to the bevels, secondary bevels...... then you'll start to break them all when you find a reason to do so.

Good luck.......

if all of the carving experts wrote their "rules not to do" on grids and you made a grid of all possible sharpening methods and overlayed them, you'd have a solid picture with no cell showing as an allowable method.

 

[D_W]

here's a generalized rule of thumb on sharpening, unless you need the bevel in a specific place at a specific angle because you're riding it as a guide.

sharpen to a shallow angle until the edge takes on damage if the edge seems blunt. When it takes damage, add a degree or two until it doesn't.

if it still seems to blunt once you find that, shallow the angle again and buff just the tip instead until the edge doesn't take damage.

I've run into carvers who buff only (even includes randall rosenthal who used to be kind enough to post a little on sawmill creek) and carvers who say they never modify the tip of a tool but have a stropping regimen and sharpening regimen that never fully removes the apex (though they say they do, they sharpen lightly to leave just a bit of it, which allows the apex to remain ever so slightly rounded). they will say things like "the edge won't behave properly until it's been sharpened a few times".

Unless you need a perfect apex and a specific fat bevel to ride, a combination of bevel and tip treatment will get much closer to a good carving edge that doesn't chip and doesn't crush fibers needlessly.

Same thing is true of carving knives, kitchen knives, etc.

 

[Ttrees]

Chris suggests in the video somewhere about 20 degrees, honed the same cutting angle as the work, and a softened heel to avoid scoring the work,

and does suggest suggest an inside bevel of about 5 or 10 degrees, honed whilst close to the chest for rigidity with the nice hones from Norton.
Aim for a flat bevel, but if slightly rounded still OK actually preferable, (but that's no excuse to aim for a rounded bevel he mentions. !)
so long as one can still cut without tipping the chisel up, i.e keeping the 20 degrees "low cutting angle" which is just about enough to get the knuckles underneath.
I see it correlates with Jacobs book.

One can see the "low cutting angle" he emphasizes on, and the inside bevel.

 

[mudman]

I did check what I was taught against what Chris says in the book I have and he has a section on secondary bevels on page 117. and re-reading it, he was talking about a secondary on the outside rather than the inside. So I mis-read it. I am rather glad of that as it means that my old tutor was right.

 

[Argus]

Chris suggests in the video somewhere about 20 degrees, and does suggest suggest an inside bevel of about 5 or 10 degrees, and a softened heel
Aim for a flat bevel, but if slightly rounded still OK actually preferable, (but that's no excuse to aim for a rounded bevel he mentions. !)

That's the essence of Chris Pye's basic layout.
Combining the two gives a total angle around 25-30 degrees.

In practicality, very few gouges have inside cannals that are free of machine marks, so an inside bevel formed with slips is essential to provide a flawless cutting edge adjoining the main bevel. This is especially true of old gouges which were usually forged. Both of these are formed on stones or slips on the insides, then refined on strops, even when in use. Every few cuts, I give the tool a few slaps on a leather strop.


In many cases the inner bevel is essential for forming the outside faces of cursive work..... 'P' 'D' etc when the gouge is used reversed, or canal-down.

 

[Jacob]

I did check what I was taught against what Chris says in the book I have and he has a section on secondary bevels on page 117. and re-reading it, he was talking about a secondary on the outside rather than the inside. So I mis-read it. I am rather glad of that as it means that my old tutor was right.

Must be a different book. I'm looking at "Lettercarving in Wood" and "Woodcarving Course & Reference Manual" - with in and outside bevel picture on page 26.

 

[mudman]

Must be a different book. I'm looking at "Lettercarving in Wood" and "Woodcarving Course & Reference Manual" - with in and outside bevel picture on page 26.

Yes the one I have is Woodcarving: Tools, Materials and Equipment

 

[DavidRa]

Thanks to everyone who has taken the time to post an answer to my question, lots to absorb, some links to follow up, some experimentation to try and lots to practice.
I also had an answer from Classic Hand Tools, ( bought from them) and they suggest 15 degrees on each side of the twin bevel # 1 which ties on to the combined 30 degrees mentioned by a number of you.

Off to the wood yard for some poplar

 

[Sean Hellman]

With any tool the bevel should be as small as possible without chipping, rolling or degrading. This will depend on how you use the tool for example pushing by hand or hitting. It also depends on the wood and the quality of the steel among other things.
Both bevels need to be flat from the edge to the shoulder for this type of carving. The shoulder of the bevel can be convex.
The biggest issue is keeping the bevels flat and not convexing or rounding over, as mentioned. Mechanical stropping can round the edge over within a second or two.
If freehand sharpening do not push the edge up and down the stone with the edge parallel to the narrow end of the stone, instead skew the chisel to 45 degrees or more to the side of the stone or even parallel to the long edge. I find, as do my students, that a flatter bevel is ground or honed with less chance of rocking the tool creating a convex bevel.

Sharpening for many is an issue, frustrating and sometimes does not work, it is all about practise and objective evaluation of self, process and study of the tool. My study, writing and down the rabbit hole research of sharpening has taught me that observation of the edge is one of the most useful tools in sharpening. Buy a loupe, use a good light, or even use a binocular microscope. I even had the opportunity of using and electron microscope at Plymouth diversity a couple of years ago, the images are used in my book Sharp.

 

[Jacob]

With any tool the bevel should be as small as possible without chipping, rolling or degrading. This will depend on how you use the tool for example pushing by hand or hitting. It also depends on the wood and the quality of the steel among other things.
Both bevels need to be flat from the edge to the shoulder for this type of carving. The shoulder of the bevel can be convex.
The biggest issue is keeping the bevels flat and not convexing or rounding over, as mentioned.

Flat bevels not essential. Two bevels not essential. Just myths of the modern sharpening fraternity. Difficult to achieve anyway if not using a machine or a guide. Slightly rounded bevels is the norm with trad sharpening. Not deliberately, it's just easier to relax a bit!
Rounded bevels can be essential for carving - it's obvious really, a lot of carving involves a scoop action especially gouges which go in and come out of a smooth cut

Mechanical stropping can round the edge over within a second or two.

Not if you are careful. I strop on face of an MDF disc + autosol, on outboard end of lathe. Very fast almost instant polish.

If freehand sharpening do not push the edge up and down the stone with the edge parallel to the narrow end of the stone, instead skew the chisel to 45 degrees or more to the side of the stone or even parallel to the long edge. I find, as do my students, that a flatter bevel is ground or honed with less chance of rocking the tool creating a convex bevel.

Rocking is perfectly OK as long as you dip rather than lift, so that the edge doesn't get dubbed over 30º, or your chosen angle. in fact it's a very efficient way of hand sharpening - you start at 30º and dip the handle as you go, which means you can put a more force into and make it faster, but still control the edge angle.

There's a lot of different opinions about sharpening!