True or false.....?

[Odie]

Two gouges......one sharpened at 25°, and the other sharpened at 30°. Both are sharpened using exactly the same method.

True or false.......the gouge sharpened at 25° is sharper.

True or false.......the gouge sharpened at 30° will hold an edge longer.

Tick, Tick, Tick, Tick.........Buzzzzzzzz! 😀

ko

 

[Jamie Straw]

What I suspect you're expecting is:
25° = sharper
30° = lasts longer

Not at all sure this is technically true, especially the "sharper" part. 5° isn't all that much on the fine edge of an M2, M42 or V10 gouge edge, yes? What technique do engineers use to measure sharpness? Neither lasts long when I'm beating up a piece of Black Locust.😛

 

[hockenbery]

True true

 

[Owen Lowe]

I will disagree with true/true.

Both can be equally sharp but will have differing resistance to severing and pushing material out of the way. (Though 5 degrees would probably be difficult to measure for most of us.) Additionally, the included angle at the respective edges would yield different surface qualities after the cut. In other words, the higher angle may cause more tear-out due to the more acute angle of the severed material exiting from the tool edge.

The 25 degree edge will be more susceptible to edge-rolling or dulling abrasion, but, a dull 25 is exactly as dull as a dull 30 degree edge. Sharpness being equal, there is more to consider than edge longevity.

 

[Odie]

True true

That would be my guess, as well Al......but, it does look like there is some disagreement with that assessment. 😵

It's only my guess, though.

Suppose the hypothesis is 25° vs 40°.....would that make a practical difference?

ko

 

[Odie]

Both can be equally sharp but will have differing resistance to severing and pushing material out of the way.

Now that I think of this a little.......Owen does make some sense here.....😉

.....and, assuming that is true, then the correct answers would be false/true.....!😱

ko

 

[Bill Boehme]

I agree with Owen.

What you're really asking isn't sharpness, but rather how well one edge cuts compared to another. A 20° edge and a 60° edge can both be perfectly sharp ... that is, the edge is the intersection of two perfectly smooth surfaces such that the edge itself has zero width.

The more acute edge would work better for cutting a tough steak and you could also say that the more acute edge would last longer because the fatter edge would be unsatisfactory from the get-go. However, if you're shearing heavy sheet metal, the more acute edge would fail too soon to be of any use. Wood falls in between these extremes and there is a wide variation in wood hardness as well as what type of cutting we need to do. Sometimes one is better than the other and other times, the opposite is true. How long the edge lasts is generally of secondary importance.

 

[john lucas]

Yes the equally sharp in terms of the two edges coming together at a point will make more difference than an angle of 5 degrees. Woodturning magazine did a study to find out if sharpening to a finer grit would accomplish anything. What they found was the finer grit produced an edge that held up longer. The hypothesis was that what we would consider dull is the peaks are a certain bluntness. The tool sharpened to a finer grit had taller peaks and tool longer to wear down.
But back to your original question. the more acute angle will cut cleaner most of the time than the blunter angle (your using the term sharper but if you read what I put above I think the term acute or blunt is better). I recently changed my spindle roughing gouge from an angle of 35 degree included angle back to 45. doesn't cut as clean but the edge doesn't chip as easily. As you can tell by this I use my spindle roughing gouge a little different than most people. Most SRG I see are ground really blunt, like 60 to 75 degrees. They use them more like scrapers. I use mine to almost completely turn my mirror handles so the more acute edge cuts cleaner and saves me a lot of work with the skew.
when I do a demo I turn my mirrors with a bowl gouge sharpened about 55 degrees or so. I usually will make a pass with that, and then a partial pass with my 35 degree spindle gouge and then another area with my Hunter Osprey that has an edge somewhere around 27 to 30 degrees. On some woods it's really noticeable the difference in the quality of the cut. Some woods, like curly maple or birds eye maple will actually have less tearout with a blunter edge. I guess that's what the hand plane guys learned years ago.

 

[hockenbery]

Anyone ever seen a fat razor blade?
While you can get an axe sharp enough to shave with it will never be as sharp as a razor.
Acuter angles get sharper.

Most people using a side ground gouge take advantage of the different shapnesses the edges.
In the Ellsworth grind
The nose is 60 degrees being less sharp it is less grabby and is used to begin cuts.
The edge off the nose at the beginning of the wing is about 45 degrees this is the part use for most of the cutting it is sharoer and holds the edge a long time
The wing is 25-30 degrees and use in the pull cut will often cut punky wood that the less sharp 45 degree part tears out.
There are of course changes in the cutting angles too.

 

[robo hippy]

Hmm, I would say that sharpness is the same if you use the same metals and the same sharpening process. As to which lasts longer and cuts cleaner, there are a lot of variables. Presentation makes a huge difference. Higher shear angles will cut more cleanly than low shear angles, and the bevel angle plays a very minor part if it plays any part at all. If you have a 45 degree bevel, and present it at a 45 degree shear angle, that makes it a more acute/pointy angle. A higher shear angle does not make for a good way to do heavy stock removal, where a more scraping type cut does. Yea, it may not be pretty, but it works.

I have always been suspicious of the sharper/finer edge lasts longer than the coarser edge more serrated edge. I tried with my Tormek, and unlike some claims that the Tormek edge lasted much longer, I could tell no difference. With my 600 and 1000 grit CBN wheels, the finer wheels would make a cutting edge that would cut more cleanly, but would dull very fast when used for heavy roughing. One theory, not mine, was that a more serrated edge had fewer teeth to wear down. Possibly. The scraper burrs from the fine wheels are not nearly as heavy duty as the ones from the coarser grits, and wear out and/or dull much faster.

robo hippy

 

[Raul McCai]

True or false.......the gouge sharpened at 25° is sharper.

I think it's a question of vernacular.
More acute for sure
But I did feel a sharp pain very acutely when the keen knife cut me

True or false.......the gouge sharpened at 30° will hold an edge longer.
ko

Probably so.

 

[Zach LaPerriere]

One theory, not mine, was that a more serrated edge had fewer teeth to wear down.

I think that's a fair theory. I figured the spaces between the teeth may also stay sharp longer and possibly don't don't dull as fast as the teeth, but I really don't know.

I tried sharpening my 3/4 gouge for roughing at 400 for a couple of days. No question it's sharper at first, but it really doesn't last. My rough estimate was 400 lasted half as long as 80.

Make me wonder about a courser CBN wheel and how long that edge would last for roughing. I'm sure there's a limit in trade-off at some grit, I just wonder how much lower you could go.

 

[Roy Hennagir]

I'm a firm believer that learning to sharpen tools is a huge problem with all types of woodworking. Of course angles make a difference but first you need to know what sharp is and how to get there. I don't believe (insert famous name of choice) signature grind works any better than any other grind when it's dull. If you understand how to get to sharp then a couple degrees in angle won't matter. When it gets dull and you can feel it then you sharpen.

I might be wrong but if you understand what sharp is and you can get there consistently can't you just copy (inset famous name here) signature grind if you have the same tool steel in the same shape?

Isn't the key is the ability to sharpen?

 

[Mike Johnson]

blas·phe·my
ˈblasfəmē/
noun

1. the act or offense of speaking sacrilegiously about God or sacred things; profane talk.
   "he was detained on charges of blasphemy"

😉

 

[hockenbery]

Isn't the key is the ability to sharpen?

A few degrees in bevel angle is not important.
Sharpen and profile are critical.

A gouge has to have a continuous convex edge (flats allowed) wing to wing.
And an edge angle some where between 80 degrees and 20 degrees
A sharp gouge with dips in the profile is just going to catch more effectively than a dull one with dips in the profile.
A gouge with a bevel angle above 80 will not cut well. A gouge with a bevel angle less tha 25 is going to be uncontrollable but will cut great for a while.

Any gouge with sharp edge and continuous convex edge is usable for turning however the profile and bevel angle determines what cuts it Will do well.

 

[John Torchick]

Let's expand this thread and define "scary sharp." Interested as I just got my Rikon slow speed grinder and Wolverine jig set up. Watch the chips and shavings fly!

 

[Odie]

I'm a firm believer that learning to sharpen tools is a huge problem with all types of woodworking. Of course angles make a difference but first you need to know what sharp is and how to get there. I don't believe (insert famous name of choice) signature grind works any better than any other grind when it's dull. If you understand how to get to sharp then a couple degrees in angle won't matter. When it gets dull and you can feel it then you sharpen.

I might be wrong but if you understand what sharp is and you can get there consistently can't you just copy (inset famous name here) signature grind if you have the same tool steel in the same shape?

Isn't the key is the ability to sharpen?

Roy.......I've always felt exactly the same way. I can remember telling myself my tools were sharp years ago, and I know otherwise as I look back from today! There are plenty of turners who will swear their tools are sharp, when they really aren't.

You're right......getting sharp is very "key", but only a piece of the pie. Knowing how to use that sharp tool is a whole 'nuther ballgame! 😀

ko

 

[Roy Hennagir]

A few degrees in bevel angle is not important.
Sharpen and profile are critical.

A gouge has to have a continuous convex edge (flats allowed) wing to wing.
And an edge angle some where between 80 degrees and 20 degrees
A sharp gouge with dips in the profile is just going to catch more effectively than a dull one with dips in the profile.
A gouge with a bevel angle above 80 will not cut well. A gouge with a bevel angle less tha 25 is going to be uncontrollable but will cut great for a while.

Any gouge with sharp edge and continuous convex edge is usable for turning however the profile and bevel angle determines what cuts it Will do well.

I'm learning the lathe. That means a new set and type of tools.

I have been a handtool horder/user for about 25 years. The surprising thing is that no matter the place garage sale, eBay, auctions, estate sales and flea markets I have found very few sharp tools. What used to be considered a basic skill in woodworking has turned into mythical voodoo.

To me sharp is sharp. Dull is dull.

Understanding the an edge is ground wrong does me no good if I lack the ability to bring the tool to a sharp edge. If I can't sharpen it how on earth am I going to regrind it to a satisfactory profile? If I can sharpen the tool and I understand what sharp is the regrinding a profile is no big deal. I know I will be able to sharpen it no matter what the profile is.

If I can't sharpen, that dip in the profile of my wing may as well be my signature grind. I'm stuck with it.

 

[Roy Hennagir]

That is an edge at x20 magnification on a round knife for leatherworking. This was supposedly "razor Sharp" to the guy who owned the round knife it was sharp.

This is one an example, of hundreds.

Teach someone to sharpen on something simple like a hand chisel, only one angle. Then teach the same level of sharp on a hand operated carving gouge and the rest is easy. Same sharp applies to all, the angle and tool to get there is what's different.

 

[Roy Hennagir]

Roy.......I've always felt exactly the same way. I can remember telling myself my tools were sharp years ago, and I know otherwise as I look back from today! There are plenty of turners who will swear their tools are sharp, when they really aren't.

You're right......getting sharp is very "key", but only a piece of the pie. Knowing how to use that sharp tool is a whole 'nuther ballgame! 😀

ko

I can get them sharp, I'm far from know how to use them!

 

[Mike Johnson]

Roy,

You should visit a straight blade razor blog, everyone has an opinion on what is sharp and how to sharpen one.
There are plenty of different lathe tools and each one has a variety of possible cutting edge profiles which can greatly enhance the abilities of the wood turner. It takes time to master each tool and learn the endless number of techniques developed over the years by the people that dedicated the time and resources to learn them. Doubtful that you will ever find anyone that knows it all. 🙂

 

[hockenbery]

I'm learning the lathe. That means a new set and type of tools.

To me sharp is sharp. Dull is dull.

If I can't sharpen, that dip in the profile of my wing may as well be my signature grind. I'm stuck with it.

Experienced turners sharpen often.

I encourage you not to become stuck witha dip in your gouge profile.
A dip in the wing or nose is removed by sharpening everything but the dip more.

Rolling the tool on the wheel is essential for maintaining a convex profile.
If you hold the tool still on the wheel like you would a flat chisel you get a dip because the flute is curved.
When grinding the nose keep the tool rolling and less pressure.
I have my students grind each wing twice and then once from wing to wing to sharpen the nose and remove any facets.
You will get it!

 

[john lucas]

Well there's sharp, and there's really sharp. When I did an experiment last year to see if HSS or particle metal would not sharpen as well as High Carbon steel I really pumped up my sharpening. For those who didn't see this test there isn't any difference. I was able to get them all "scary sharp". The particle metal needed a yellow honing bar. The green bar worked but just took a lot longer. I think that is part of why people don't get the tools really sharp. They simply stop too soon. What I did on those tools was to use my sandpaper scary sharp system and sharpened to 1500 grit. Then I honed on a hard felt wheel. Cutting paper and hair I could not tell the difference in a fresh razor blade and the edges of those 3 tools.
To back up a little I have played with and planes a fair amount. I'm not good mind you but it's a good learning lesson for what is sharp. Early on I thought I had a sharp blade. It would shave hair. It just never seemed to cut like you see those Japanese guys pulling off huge shavings. So I would go back and tune up my plane and then try a different sharpening method. Better shavings but still not like those guys. A few years later I tried again. Again better but not like those guys. After doing the test on turning tools I went back to my hand plane and used the same method. Noticeable better. No I'm not there with the Japanese yet. What I learned from this is that sometimes you simply don't stay on the proper grit long enough. With my diamond hones when I sharpen I raised a burr on the backside that you can feel. Sharpen the other side and it moves the burr over. When you can feel that bur you know you've gone far enough with that grit. However when you get to strop you really can't feel the burr and it's harder to know when you've done enough. Takes practice.
for turning tools of course we usually don't go that far. However 2 good ways to tell is to look under a bright light. You should not see the edge. If you do it's dull. second you can usually feel the burr on the inside after you sharpen. I often remove this burr with a round diamond hone but it's not necessary since it wears off really rapidly when turning. I just feel refining the inside has to help and you can tell when you cut that it does. The other way to tell. The tool should cut wood with no force necessary. If your having to work at it then it's not sharp. Years ago John Jordan was doing a demo and he usually used just one hand when roughing out the vessel to show people that if done properly with a sharp tool you don't need any force. I stepped up to take a photo and John said wait, and he put the handle in his belly button and continued roughing with no hands. You can only do that with a very sharp tool and proper technique. That photo went in the Journal and boy did we take a lot of flack over how dangerous and stupid it was. We still laugh about that one.

 

[Bill Boehme]

Let's expand this thread and define "scary sharp." Interested as I just got my Rikon slow speed grinder and Wolverine jig set up.

Scary sharp is just another way of saying sharp. Sometimes the adjective scary is used if the Bandaid test was used to check the edge and positive results were observed. Dull is everything that isn't sharp.

... That is an edge at x20 magnification ...

Is that the back or the front of the blade? 😀 Or, were they the same? 🙄

It's a crime to bludgeon wood with a blurt instrument.

 

[Bill Boehme]

.... Cutting paper and hair I could not tell the difference in a fresh razor blade and the edges of those 3 tools.

So, are we now splitting hairs?

 

[Roy Hennagir]

Scary sharp is just another way of saying sharp. Sometimes the adjective scary is used if the Bandaid test was used to check the edge and positive results were observed. Dull is everything that isn't sharp.



Is that the back or the front of the blade? 😀 Or, were they the same? 🙄

It's a crime to bludgeon wood with a blurt instrument.

Bill,
That's the cutting edge facing you. Those round knives are beveled on each side, there is no jig to sharpen them.

I've brought quite a few of these back to life. This is a before and after picture of one of them.

Sharpening this by hand is the only way I know how to do it. It must be sharp or you can not cut leather with them. When people say they hone an edge and use a stone to do it they are still sharpening. I use a leather strop and honing compound to hone.

A handplane will plane leather and a leather knife will cut wood. It's not the optimum use of the tool but they will do it. You only need to keep them sharp.

 

[Odie]

Experienced turners sharpen often.

Roy.....Al hits on a very important point many new turners never seem to get at their stage of learning.....and, it usually takes a little "stick time" before it "clicks". With some turners, it takes a lot of "stick time"!......and, I'm probably a good example of the latter! All tools dull with use.....very little use. Matter of fact, the tool starts to dull the very moment it's put into use. Now, there is a point where that sharp tool begins to not produce as fine a cut as when it was freshly sharpened......and, that point will vary with what you're doing with the tool, AND the specific piece of wood you're working on. It takes a little understanding, or "knack" that will come with experience, to know just when to re-sharpen......and, it won't be the same as it was the last time you used it (because the variables will have changed). It's often that I get less than one minute of use, before I'm truing up the edge again.......that's right.......60 seconds of use!

My tools dull quicker than some turners, because after trying some tools steels that have a longer lasting edge, I've decided there is a real advantage to using nothing but M2 steel. Yes, it does dull faster than some of the exotic steels, but the "window" where you are thinking you might need to true up the edge is much shorter. THAT is an advantage, because you spend much less time deciding whether or not you need to re-sharpen.

The whole point of advanced turning is to not require much sanding. (The more sanding required, the less geometric perfection can be achieved.) Keeping that tool cutting to the very best it can possibly do, is key to eliminating much of this sanding. You'll never get to the point where you can eliminate sanding entirely.......but, you can get much closer to this goal than some people realize. 😀

ko

 

[robo hippy]

Odie, I had used nothing but V10 and M42 HSS for years, and tried a parabolic fluted M2HSS gouge. I was amazed at how fast it went from sharp off the wheel to 'back to the grinding wheel'. The harder steels all will hog off a lot more wood before you need to go back to the wheel. Both need to go to the wheel for a finish cut.

robo hippy

 

[Roy Hennagir]

Odie,
I learned sharpening on handplanes. I completely agree, you have to learn the tool. I had the pleasure of taking two years of courses at Palomar college prior to retirement from the Marine Corps. It was the cabinet and furniture technology course. I would say the 90% of the students struggled with sharpening. You had to sharpen an ordinary chisel to pass the basic course. It was amazing the lengths some of them went through to keep them sharp. They would not use them for fear of having to sharpen them again. These were all adults in thier 40's and up taking the course to learn woodworking. They did not want to sharpen, something I consider basic to woodworking. I believe that is why the carbide tools that are so prevalent in wood turning today are here. Use four edges, drop $20 in the mail and a new sharp tool bit arrives. That to me is a high price to pay for a sharp edge. You are also very limited in what you can do because those are the profiles, no grinding a new shape. Designing the project to fit the tool seems very limiting to me.

Your first post about angles, well that compounds the fear of sharpening. What if you sharpen or grind the wrong angle? If you don't know what sharp is and how to get there those tools will soon be for sale on eBay. They just don't work and this is to hard. Just take a look at the offerings on eBay for used lathe tools. Zoom in and see if you can find a sharp one.

I understand the longer lasting tool steel used for turning tools. At 1500 rpm how many inches of wood will travel across the cutting edge per minute. How much heat is produced? Way more then I'll ever do with a handplane in a week. There are all sorts of long cutting steels for handplanes too. Why is that when they are so simple to sharpen, even by hand?


I know that I am using the tools incorrectly and so the catches, vibrations, chatter marks, plowing the chisel into the spinning chuck are all part of learning. I turned a small bowl and got soaking wet, that never happened with a pen blank. I can't even imagine trying to do that with dull tools. I can't imagine trying to learn to turn with dull tools. Learning how to use the tool properly is challenge enough.

 

[Bill Boehme]

My tools dull quicker than some turners, because after trying some tools steels that have a longer lasting edge, I've decided there is a real advantage to using nothing but M2 steel. Yes, it does dull faster than some of the exotic steels, but the "window" where you are thinking you might need to true up the edge is much shorter. THAT is an advantage, because you spend much less time deciding whether or not you need to re-sharpen.

I never thought of looking at it that way, but I believe that you have a valid point about knowing when a tool is dull. My favorite bowl gouge is a ½" M2 HSS Robert Sorby, probably because of the flute shape or maybe it's the profile of the grind.which is something that I came up with while experimenting on the Tormek. I have the same grind on a ½" CPM 10V HSS Thompson bowl gouge. It's an early Thompson gouge from about 2006 or 2007 when that was the only tool he made. It has a rather narrow V flute and I think that it's not the same shape as his current bowl gouges. Anyway, because of the difference in flute shape my "signature" Bill grind looks completely different from the grind on the Sorby bowl gouge. The angle of the wings of the Thompson gouge are much thinner.

This afternoon I was turning some dry hard maple. I started with the Thompson and finished with the Sorby gouge. It's interesting that the Thompson gouge dulled within a few minutes and the Sorby lasted noticeably longer. Was it a valid comparison? Probably not ... the maple blank had warped while drying so there was a lot of interrupted cutting initially. Also the thin wings on the Thompson gouge would dull quicker. The Sorby was mainly used for lighter cuts to smooth and flatten the surface.

I'm a firm believer that learning to sharpen tools is a huge problem with all types of woodworking. Of course angles make a difference but first you need to know what sharp is and how to get there. I don't believe (insert famous name of choice) signature grind works any better than any other grind when it's dull. If you understand how to get to sharp then a couple degrees in angle won't matter. When it gets dull and you can feel it then you sharpen.

I might be wrong but if you understand what sharp is and you can get there consistently can't you just copy (inset famous name here) signature grind if you have the same tool steel in the same shape?

Isn't the key is the ability to sharpen?

Famous name signature tools are primarily a product of manufacturer marketing. In many cases, the grind is the only thing that is different from the standard grind.

 

[Roy Hennagir]

I'm sure this discussion has gone on since man figured out how to temper steel.

I use a lot of handtools that are getting on close to 100 years in age, it's amazing how well some of the hold an edge. They did not have computerized ovens and CNC machines to do the work.

I clean up, sharpen and use old handsaws. They are taper ground with the teeth being the thickest part of the taper and the spine being the thinnest. Try and drill one with a normal drill bit. Please clamp the blade to the drill press. They are everywhere on the second hand market. Now find someone who can sharpen one. That used to be a carpentry basic skill.

In reality if you can sharpen then you only need the tool blank. Take a fluted M (whatever) steel rod of the length in the size you want, profile it, handle it, and sharpen it. Bowl gouge. Why do they come preshaped and not sharp for the most part?

Need a three point 1/4" tool? Dig out the high speed steel 1/4" drill bit, profile the end that inserts into the chuck, sharpen it, handle it and there's a tool. You do have a box of dull drill bits don't you?

Shouldn't the easiest part of turning be sharpening? It's the one thing that is required for everything you turn.

 

[Odie]

Odie, I had used nothing but V10 and M42 HSS for years, and tried a parabolic fluted M2HSS gouge. I was amazed at how fast it went from sharp off the wheel to 'back to the grinding wheel'. The harder steels all will hog off a lot more wood before you need to go back to the wheel. Both need to go to the wheel for a finish cut.

robo hippy

Howdy robo........Any type of steel will "hog out" quite a bit more wood in the initial stages, simply because the requirements of the cut are much less critical.....until you get to the final cuts. In spite of that, the harder steels will still outperform the M2 steel.....there is no denying that. For turners who have spent a lot of time sharpening, and it has become more or less "habitual", sharpening more often shouldn't be much of an obstacle, if it keeps your tool sharpness factor "within the zone". Regardless, from one turner to the next, I'm sure there are some "personality" differences that make perceived goals not quite the same......If that were not the case, then woodturning as a spectator sport would become very boring! 😀

Thompson gouge dulled within a few minutes and the Sorby lasted noticeably longer. Was it a valid comparison? Probably not ... the maple blank had warped while drying so there was a lot of interrupted cutting initially. Also the thin wings on the Thompson gouge would dull quicker. The Sorby was mainly used for lighter cuts to smooth and flatten the surface.

From my point of view, and as you have observed, Bill......it's no mystery that your Thompson tool dulled quicker than the Sorby, because the variables have changed between using one, over the other. If you had used both tools under the exact same circumstances, I suspect the Thompson would have outlasted the Sorby. Given your background, you would be the likely one to pursue the meaning of the "why", while someone such as myself is more accepting of my perceived notion of "what is"! 😀

ko

 

[hockenbery]

In reality if you can sharpen then you only need the tool blank. Take a fluted M (whatever) steel rod of the length in the size you want, profile it, handle it, and sharpen it. Bowl gouge. Why do they come preshaped and not sharp for the most part?

Need a three point 1/4" tool? Dig out the high speed steel 1/4" drill bit, profile the end that inserts into the chuck, sharpen it, handle it and there's a tool. You do have a box of dull drill bits don't you?

Shouldn't the easiest part of turning be sharpening? It's the one thing that is required for everything you turn.

Until a few years ago new gouges came with no profile.
Today most manufactures profile their gouges. They don't really sharpen them.
signature gouges are profiled to the grind of the signature turner. The other gouge to a sort of generic side grind that makes it easier for the buy to grind it to the profile theynuse.

If you true a flute shape on your grinding wheel you can start with round bars and grind your flute too.

Lots of turners make at least a few of their own tools. Some turners are more tool maker than turners.

 

[robo hippy]

Can't remember his name, Roger maybe, who used to write for American Woodworker, but some thing like "How do you know when your table saw blade needs to be sharpened? When it sets off the smoke alarm." Learning when your edges need to be redone is a bit of an art, and learning to 'feel' what the tool is doing. Even when doing heavy roughing, if the tool is dull, you have to expend more energy to cut, which I don't like to do. For heavy roughing the 'lasts 5 times longer' types of metals will keep a working edge, that you don't have to force, much longer than standard M2. True that with roughing, surface is not as important as shape, which is part of why I use scrapers for my heavy roughing. 'It looks a little rough!' 'Well, that's why they call it a roughing cut.'

Bill, your comment on the 'thin wings' on the Thompson gouge brings up another point, which is flute shape determines a lot as to which type of nose profile works best. The problem with the deep V like the Glaser gouges, especially when using jigs to sharpen is that you can end up with really thin wings because you can't roll the gouge over far enough to get a proper angle on them, and that is why they end up so thin, which is why they went dull more quickly. To me, that is one advantage of platform or free hand sharpening as you can control the wing shapes and angles better with more roll. Most of mine have a very tiny cutting bevel, and as near as I can tell, they are similar to what Johannes Michaelson does with his set up. Doug's U flute, to me does not make for a good swept back grind, but does make an excellent 45/45 grind, which is my go to profile for finish cuts. V flutes make lousy BOB tools, but do a fair swept back profile. That thin wing may be good for those that like to ride the wing when going down the inside of a bowl rather than the nose, but that is a cut I don't and won't use.

robo hippy