Blade Dulling/Sharpening Question

[Harvey Pascoe]

Being relatively new to bevel up planes, I'm a little disconcerted at what is happening, which is that the blade edge is rounding over on the back or non bevel side. This is not visible on the bevel side. With a rounding that is visible to the eye, say .002" this is more than what can be removed by normal sharpening (I use mostly sandpaper and micro paper on glass), and it has occurred on both of my new BU planes used for less than a week, admittedly on VERY hard wood. Blades are both A1 and O1. My other new plane, a standard angle block, this has not happened.

Seems the only way I can remove this rounding is by regrinding and if this is going to be a regular occurrence, its going to be a problem as I just had to regrind the blade on my LN #102 to get rid of it. I should add that this rounding over does not seriously degrade performance YET - but its much less than optimal.

Anyone else have this problem and if so what is your solution?

[David Weaver]

It's just the wear bevel on a BU plane. That's just the way it goes when you use a low angle BU plane. If it's not happening on a standard angle plane, it's because the higher clearance angle keeps the back side from taking as much wear from the wood you're planing.

It might not be as deep as you think. Work the wear bevel on your paper with finger pressure at the end of the bevel, and you should be able to get rid of it just as part of your normal routine.

I have one BU plane left. I used to have a fair amount of them. For all of their benefits, I'd rather camber a BD plane iron and have that wear on the bevel side instead of the back of the iron.

[Terry Beadle]

I agree with Mr. Weaver. You should be able to freshen the cutting edge on a BU blade with a simple honing of the flat. I would think that a .002 wear bevel is indicative of going too long between honing or polishing stone maintenance. You should not be getting such a thick wear bevel. Since you are using micro paper on glass, I'd keep a hard maple contact cemented hone handy near the bench and use it after every 10 ~ 15 min of work to refresh the BU edge. You may need to increase the cutting angle of the bevel by another 5 degrees or so to toughen it up for trouble grained wood.

[glenn bradley]

+1 on what has been said. I'm no expert but, being able to even go through a decent planing session without stopping to freshen the edge is rare let alone "less than a week". Touch up often and be happy.

[Derek Cohen]

You should be able to freshen the cutting edge on a BU blade with a simple honing of the flat.

... or use the Ruler Trick. This will remove wear in the area where a wear bevel develops.

Regards from Perth

Derek

[Tony Shea]

I'd have to agree with Derek. If you're planning on using these BU planes on very dense wood then this is the price you pay for BU planes. The fastest method to get rid of it is using the ruler trick, a slight back bevel. I personally hate the ruler trick but do use it when I have to. I like my sharpening consistant and using the ruler trick on a couple irons and not the others gets kinda confusing.

The other method to maybe cut down on the wear is to make sure you lift the plane off the wood on your back stroke instead of dragging it back towards you.

[Tri Hoang]

The wear bevel is more profound when the BU planes are used on abrasive/hard/dense wood as well as when taking thicker shavings. So if you can't avoid those kinds of wood, take lighter cuts. If you are using the Veritas BU planes, get their M2 HSS blade for more abrasive wood. I could not get the M2 HSS as sharp as A2/O1 on my stones but it's sharp enough and loooooong lasting.

[Harvey Pascoe]

Oh, I do take very light cuts, striving for .002". Now, can you enlighten me on what the Ruler Trick is?

>>>A simple honing of the flat.<<< Does this mean the non bevel side? If so, then I end up with a double bevel, right?

I have a micro bevel that is so low that I cannot visually see any change in angle. It is there merely because I don't want to polish the whole bevel. On a 25 degree blade what is the maximum you'd want a micro bevel to be?

For working very hard wood, would I be better off regrinding this blade to a higher angle, such as 38 degrees?

[Tri Hoang]

The profound wear bevel is cause by low clearance angle (12* bed) on these BU planes. Increasing the micro/primary bevel will strengthen the edge but does not solve the wear bevel problem. Using the ruler trick may make it worse.

You may want to grind back the blade a little (1/16" or so) and re-sharpen to see if it helps since sometimes the heat treating process left a weaker edge on new blades.

[Andrae Covington]

...Now, can you enlighten me on what the Ruler Trick is?

>>>A simple honing of the flat.<<< Does this mean the non bevel side? If so, then I end up with a double bevel, right?...

David Charlesworth's Ruler Trick is to place a very thin metal ruler on the sharpening medium in a position to slightly elevate the non-cutting end of the blade, with the non-beveled face down. Then as you slide the blade back and forth perpendicular to the ruler, applying pressure near the cutting edge, you are creating a very shallow double bevel.

Here's a PW link with Charlesworth describing the process (http://www.popularwoodworking.com/techniques/the_ruler_trick/2)... it's the last section at the bottom of the page. However this FW link with Thomas Lie-Nielsen describing the process (http://www.finewoodworking.com/pages/w00177.asp) has an illustrative photo.

[Terry Beadle]

To answer your question, yes the recommendation is to hone the flat side of the blade. A ruler trick would be of some use but it would not be as Mr. Pan says as good an idea on a BU plane. The point of the wear burr problem is that even if you put a ruler trick process to the blade, you would still get the wear issue. Honing more frequently more likely will solve the problem.

The recommendation of grinding off another 1/16th of the blade to get past possible heat treating aftermath issues is a good one but it's possible that's not the problem. We would need to know how frequently you hone or how long you go between honings and the woods you are planing in that causes you this issue. Also how new is the blade? When you say new...do you mean a couple weeks or this year? But all that aside, if it is new, really new as in a couple days or weeks, then the heat treat recommendations are a good guess as to the culprit.

Another thing you can try is to put a 35 ~ 37 degree micro bevel on the blade and see it that doesn't solve the problem. The higher angle than the standard 25 ~ 30 degrees that most blades come with would give more support to the cutting edge.

[David Weaver]

You should be able to freshen the cutting edge on a BU blade with a simple honing of the flat.

... or use the Ruler Trick. This will remove wear in the area where a wear bevel develops.

Regards from Perth

Derek

I agree. I have not done it on my lone remaining full-sized BU plane, but if I had a wear bevel that seemed to be obnoxiously prominent, I wouldn't be afraid to. I can't see a lot of difference between a relief angle of 10 degrees and one of 12. To reduce the length of the wear bevel, in my limited "paying attention", relief has to be a lot higher than 10 or 12 degrees.

Care for someone just learning the ruler trick should be exercised to avoid making an unnecessarily long back bevel from the ruler trick, though, it only needs to remove the wear, and to the extent that it is made overly long / deep into the blade, it's just more work later.

I have accumulated a lot of planes, sold off a lot of them, but noticed that in most cases, the user who had the plane before me would've benefitted from using the ruler trick - as there was significant wear or an edge that wasn't fully honed on the back side of the iron, while the bevel side was fully polished.

Back bevels and microbevels are especially helpful if the polish stone being used is not able to cut the blade too well, or in a case of sharpening a smoother, where the iron is superbly hard and the finish stone is also exceedingly fine / slow. There's no great reason to try to polish even all of the hard steel if the blacksmith did not do a good job of stretching it, and the layer is left thick, unless someone likes to exercise their re-enacting skills, or they just enjoy swirling the iron around on the stone. the wood will certainly not reflect the effort.

Everyone has opinions about it, I guess, and whoever is doing the planing and sharpening can decide what they like to do.

[David Weaver]

Oh, I do take very light cuts, striving for .002". Now, can you enlighten me on what the Ruler Trick is?

>>>A simple honing of the flat.<<< Does this mean the non bevel side? If so, then I end up with a double bevel, right?

I have a micro bevel that is so low that I cannot visually see any change in angle. It is there merely because I don't want to polish the whole bevel. On a 25 degree blade what is the maximum you'd want a micro bevel to be?

For working very hard wood, would I be better off regrinding this blade to a higher angle, such as 38 degrees?

On hardwoods, you want it to be at least thick enough that the edge is supported. I don't think that's very thick, but it does negate the objective of making it razor thin or near invisible, unless you like to see chipouts. You also need to actually be able to see it to be sure that the polish goes all the way to the edge.

I would try a minimum of 30 degrees for whatever the final bevel is, you haven't got a great reason to smooth hardwood at 37 degrees in a bevel up plane, and the iron will lean toward wear instead of chipout at 30 degrees, especially if you bull it some.

As far as how deep the microbevel can be, or the chord length of the edge, or whatever you want to call it, when it takes too much time to refresh the microbevel (if you use two bevels) or to move the secondary bevel back so that you can polish the third bevel (if you use 3), then it's time to grind or do whatever you do to work the primary angle and thin out the second bevel.

Experience, and not much of it, will tell you what takes the least amount of time to get the best results.

[Wilbur Pan]

To answer your question, yes the recommendation is to hone the flat side of the blade. A ruler trick would be of some use but it would not be as Mr. Pan says as good an idea on a BU plane. The point of the wear burr problem is that even if you put a ruler trick process to the blade, you would still get the wear issue.

Although I am not sure whether Terry was thinking of me when he wrote this, I should point out that it was Tri Hoang who said this in this thread, not me, and last time I checked, Tri and I seem to be two separate people. ;)

I do fully agree with what Tri said and what Terry agreed with — if the issue is a wear bevel, using the ruler trick on the back isn't going to fix it, and it may make the problem worse.

[Derek Cohen]

To answer your question, yes the recommendation is to hone the flat side of the blade. A ruler trick would be of some use but it would not be as Mr. Pan says as good an idea on a BU plane. The point of the wear burr problem is that even if you put a ruler trick process to the blade, you would still get the wear issue. Honing more frequently more likely will solve the problem.

The recommendation of grinding off another 1/16th of the blade to get past possible heat treating aftermath issues is a good one but it's possible that's not the problem. We would need to know how frequently you hone or how long you go between honings and the woods you are planing in that causes you this issue. Also how new is the blade? When you say new...do you mean a couple weeks or this year? But all that aside, if it is new, really new as in a couple days or weeks, then the heat treat recommendations are a good guess as to the culprit.

Another thing you can try is to put a 35 ~ 37 degree micro bevel on the blade and see it that doesn't solve the problem. The higher angle than the standard 25 ~ 30 degrees that most blades come with would give more support to the cutting edge.

Hi Terry

I must say, with respect, that I disagree with all this.

As David noted, the Ruler Trick backbevel should be kept small (roughly 1/2" long). It removes 2/3 of a degree. However this is enough to remove any wear bevel that might appear. Indeed, I have been using BU planes (other than block planes) for several years on extremely hard woods, and I have not actually needed the Ruler Trick. Instead I used to strop the back of the blade. More recently I decided that using a small steel rule on my waterstones was easier. I still do not experience the incursion of a wear bevel. There is no accumulative effect once you start using the RT.

Since the OP was referring to a block plane (a LN #102 as I recall), adding a 35-37 degree microbevel would leave him with a 47-49 degree cutting angle - hardly something one ideally wants for end grain. Sorry, this is not meant to sound critical - I think you become sidetracked from the original issue (been there, done that myself) :)

Regards from Perth

Derek

[Harvey Pascoe]

Whoa! I appreciate all the advice but you guys are all using different terminology to describe the shape of the micro bevel and/or back bevel. OK, so the ruler trick adds a back bevel, I got that. I see one advantage in that since it creates a less fragile edge. I tried that on Sunday and it seems to be working, only I used the honing guide instead of a ruler which seemed rather imprecise to me. So now I got a back bevel that is perhaps .010 wide, I can barely see it.

1. My planes are all one week old, get used hard every day and I rehone as soon as I detect a decline in performance, not less than once a day (usually). If I can't take off fuzz instead of a shaving, I consider it dull.

3. I rarely do end grain so that is not an issue.

4. I work with murderously hard tropicals, so yes I know they're tough on tools, but this much wear in week?

2. The wear bevel is showing up the worst on the NV standard block, 45 total angle, 01 blade. The width of the wear bevel is too much to ever be removed by honing less than 220 grit; in other words the wear bevel is easily .015 - .020. too little for grinding, too much for honing.

5. I can't see how a tiny back bevel could make it worse, could you explain?

6 Perhaps I should put in my 38 degree blades and see how they go, though I didn't like in my BU jack, but then I didn't like that plane, period.

7. When I consider the geometry of the blade and the forces working on it, I'm mystified how you get wear on the back side. I could be wrong, but it looks to me like what is happening is not wear but bending of the edge back to a burr that then gets worn away because it sticks up, or down rather. This would also explain the very sudden decline in performance. A very fine edge at 25 degrees has got to be rather fragile. Therefore it would seem to me that reducing the finess of entry while still maintaining sharpness ought to greatly reduce - but not fully eliminate - this problem.

8. Since I have three planes used the same amount daily, the thing to do here is a little testing. I'll keep notes of what I do and how that works out and let ya know. Now that I got a grinding jig its no big deal to experiment.

[Bill Moser]

Harvey -
I have no answers, but I'd love to hear what others say to your Q no. 7. Have you looked at your blade under magnification when you sense that it's dull? Also, Derek says that the Ruler Trick should leave you with a 1/2" bevel. Maybe he meant 1/12"? Or, he has the thinnest ruler on the planet :)

[glenn bradley]

I probably should have added earlier that I have higher angled irons for my BU planes as well as the 25*. I would buy another iron before I re-ground the one I have. You would just have to re-grind again when you wanted that low angle back. I truly appreciate having multiple irons.

[Wilbur Pan]

5. I can't see how a tiny back bevel could make it worse, could you explain?

On a BU plane, the clearance angle is defined by the bed angle. This assumes that the back of the blade is flat. But if you put a back bevel on the back of the blade, such as you would using the ruler trick, the back of the blade by the cutting edge is no longer flat. If you draw this out on a piece of paper, you'll see that the back bevel will make a lower clearance angle.

If the clearance angle is lowered, that may worsen the wear bevel that you are seeing on the back of the plane blade, as the metal is going to be closer to the wood. In any case, it certainly won't improve the situation.

[Derek Cohen]

On a BU plane, the clearance angle is defined by the bed angle. This assumes that the back of the blade is flat. But if you put a back bevel on the back of the blade, such as you would using the ruler trick, the back of the blade by the cutting edge is no longer flat. If you draw this out on a piece of paper, you'll see that the back bevel will make a lower clearance angle.

If the clearance angle is lowered, that may worsen the wear bevel that you are seeing on the back of the plane blade, as the metal is going to be closer to the wood. In any case, it certainly won't improve the situation.

Wilbur is correct in principle ... but we need to define "small" backbevel. The bed is 12 degrees. About 7 degrees clearance is needed (for softwood, less for hardwood). So if the backbevel is 5 or 6 degrees, then we may run into trouble. The Ruler Trick is a mere 2/3 of a degree, so it do not affect the clearance angle. Further, since you are making no more than a back-and-forth movement of 1/2", the amount of metal removed in minimal (imperceptible). What the RT does do is remove any wear behind the bevel, allowing for a sharp edge. That there is now a 1/2" of "unsupported" steel at the front of the blade is of little consequence when blades are 1/8" thick and 1 1/2" wide.

Regards from Perth

Derek

[Tri Hoang]

I have tons of respect for Derek and hate to sound contrary to him but...if the OP got a significant wear bevel based on 12* bed, wouldn't another 1* or so created by the ruler trick make it worse? I wonder if you could cite a reference for the magic 7* clearance angle required for softwood.

[Larry Williams]

Whoa! I appreciate all the advice but you guys are all using different terminology to describe the shape of the micro bevel and/or back bevel. OK, so the ruler trick adds a back bevel, I got that. I see one advantage in that since it creates a less fragile edge. I tried that on Sunday and it seems to be working, only I used the honing guide instead of a ruler which seemed rather imprecise to me. So now I got a back bevel that is perhaps .010 wide, I can barely see it.

1. My planes are all one week old, get used hard every day and I rehone as soon as I detect a decline in performance, not less than once a day (usually). If I can't take off fuzz instead of a shaving, I consider it dull.

3. I rarely do end grain so that is not an issue.

4. I work with murderously hard tropicals, so yes I know they're tough on tools, but this much wear in week?

2. The wear bevel is showing up the worst on the NV standard block, 45 total angle, 01 blade. The width of the wear bevel is too much to ever be removed by honing less than 220 grit; in other words the wear bevel is easily .015 - .020. too little for grinding, too much for honing.

5. I can't see how a tiny back bevel could make it worse, could you explain?

6 Perhaps I should put in my 38 degree blades and see how they go, though I didn't like in my BU jack, but then I didn't like that plane, period.

7. When I consider the geometry of the blade and the forces working on it, I'm mystified how you get wear on the back side. I could be wrong, but it looks to me like what is happening is not wear but bending of the edge back to a burr that then gets worn away because it sticks up, or down rather. This would also explain the very sudden decline in performance. A very fine edge at 25 degrees has got to be rather fragile. Therefore it would seem to me that reducing the finess of entry while still maintaining sharpness ought to greatly reduce - but not fully eliminate - this problem.

8. Since I have three planes used the same amount daily, the thing to do here is a little testing. I'll keep notes of what I do and how that works out and let ya know. Now that I got a grinding jig its no big deal to experiment.

How many years has this been going on now--is it six or seven? Someone comes on a woodworking forum and says they're having trouble with wear bevels on the flat face of 12º bedded bevel-up plane irons. Some say it's lack of clearance and others say "no, all one needs is 7º of clearance." Well, no one is mentioning these problems with 20º bevel-up planes or bevel down planes that have about 15º of clearance at common pitch. Some say to use the ruler trick which further reduces clearance angle if only by 1/2º but this is more than a four percent reduction and if 12º isn't enough 4% less can't be better. If it's not clearance, what's causing this recurring problem? If 7º is adequate clearance, why is this an issue at all in 12º planes? I don't recall those who deny it's clearance offering an answer. Somehow, I don't think Harvey and the others are imagining this, especially since some have posted photos.

[Jim Neeley]

6 Perhaps I should put in my 38 degree blades and see how they go, though I didn't like in my BU jack, but then I didn't like that plane, period.

7. When I consider the geometry of the blade and the forces working on it, I'm mystified how you get wear on the back side. I could be wrong, but it looks to me like what is happening is not wear but bending of the edge back to a burr that then gets worn away because it sticks up, or down rather. This would also explain the very sudden decline in performance. A very fine edge at 25 degrees has got to be rather fragile. Therefore it would seem to me that reducing the finess of entry while still maintaining sharpness ought to greatly reduce - but not fully eliminate - this problem.

8. Since I have three planes used the same amount daily, the thing to do here is a little testing. I'll keep notes of what I do and how that works out and let ya know. Now that I got a grinding jig its no big deal to experiment.

Harvey,

FWIW, I recommend that you try a higher angle on one of the plane blades (perhaps your 38*, or 33* [to equal a 45*], or whatever is easy) and see if it goes away. You've said that you work on very hard wood and we all know that you need a higher angle on a chisel in hardwood than in softwood to avoid folding the edge.

Keep in mind that you don't have to regrind the whole bevel for this test; all you need is a secondary bevel that has some substance, such that the blade is thick enough where the bevels meet to provide rigidity, but then I'm sure you already knew that. :)

Jim

[Derek Cohen]

Larry is correct insofar as this topic comes up regularly. The trouble is it ends up as a debate, similar to the benefits of BU versus BD planes as advocated by their proponents, and there is little actual discussion.

BU and BD configurations have their pros and cons. Neither is perfect and both play an indispensible part in some workshops, certainly in mine. I value BU planes for their ability to plane at high cutting angles as much of the wood I use has significant interlocked grain. They work at these high angles more easily than do BD planes. I value BD planes for the ease of sharpening blades - my preference is to freehand blades with a camber, and BU planes with high included angles really do need a honing guide. I use both BU and BD planes equally for high angles, only BD planes for the middle range, and more BU planes for the low range.

The next point of relevance is that the blades of BU and BD configurations wear on both the back and the face sides of the bevel. There is wear from wood as it abrades both sides of the bevel. The wear that Larry focuses on is from the wood springing back. The argument is that this creates more wear where it counts on the BU blade, and that subsequent honing is made more difficult. What I have written before is that I do not argue the presence of this wear bevel, but I do see the amount of wear being exaggerated by some. The proof of the pudding is in the eating ... I have used these planes on very hard and abrasive woods for many years now, and just do not experience the degree of wear described here. Further, there are many thousands of happy users of BU planes who do not complain of their planes suddenly not working. I would argue that the numbers of expreme examples are rare.

What of the Ruler Trick when honing a BU plane blade? The amount of metal removed is extremely tiny. Don't forget that wear occurs on both sides of the blade, which means that one will also end up grinding/honing the face bevel. I honestly cannot say that I treat my BU plane blades too differently from my BD plane blades. Both have to be honed on both sides of the bevel. My single concession to the BU set up is to add a ruler-tricked micro backbevel rather than leave the back flat. If this created an acculative backbevel, that is, a greater angle and one that then encroached on the clearance angle, then I have not ever noticed it occuring.

Regards from Perth

Derek

[Derek Cohen]

6 Perhaps I should put in my 38 degree blades and see how they go, though I didn't like in my BU jack, but then I didn't like that plane, period.

7. When I consider the geometry of the blade and the forces working on it, I'm mystified how you get wear on the back side. I could be wrong, but it looks to me like what is happening is not wear but bending of the edge back to a burr that then gets worn away because it sticks up, or down rather. This would also explain the very sudden decline in performance. A very fine edge at 25 degrees has got to be rather fragile. Therefore it would seem to me that reducing the finess of entry while still maintaining sharpness ought to greatly reduce - but not fully eliminate - this problem.

8. Since I have three planes used the same amount daily, the thing to do here is a little testing. I'll keep notes of what I do and how that works out and let ya know. Now that I got a grinding jig its no big deal to experiment.
Harvey,

FWIW, I recommend that you try a higher angle on one of the plane blades (perhaps your 38*, or 33* [to equal a 45*], or whatever is easy) and see if it goes away. You've said that you work on very hard wood and we all know that you need a higher angle on a chisel in hardwood than in softwood to avoid folding the edge.

Keep in mind that you don't have to regrind the whole bevel for this test; all you need is a secondary bevel that has some substance, such that the blade is thick enough where the bevels meet to provide rigidity, but then I'm sure you already knew that. :)

Jim

Jim is spot on. The situation that Harvey now presents does NOT sound like a wear bevel issue, but sounds like a steel issue. Simply, he is planing hard wood (as he reported) with an edge that is too fragile for the circumstances. A 37 degree included angle is too low, and the steel is bending (not just abrading).

Harvey, please use your 38 degree bevel (for a 50 degree included angle), and report back to us.

Regards from Perth

Derek

[Hans Braul]

I used to have the exact same problem until I discovered the ruler trick. Problem gone.

Regards
Hans

[David Weaver]

Wilbur is correct in principle ... but we need to define "small" backbevel. The bed is 12 degrees. About 7 degrees clearance is needed (for softwood, less for hardwood). So if the backbevel is 5 or 6 degrees, then we may run into trouble. The Ruler Trick is a mere 2/3 of a degree, so it do not affect the clearance angle. Further, since you are making no more than a back-and-forth movement of 1/2", the amount of metal removed in minimal (imperceptible). What the RT does do is remove any wear behind the bevel, allowing for a sharp edge. That there is now a 1/2" of "unsupported" steel at the front of the blade is of little consequence when blades are 1/8" thick and 1 1/2" wide.

Regards from Perth

Derek

The difference in back bevel or no back bevel with the ruler trick on a BD or BU iron is so small in practice that I can't believe that it is ever even discussed as a clearance issue. I am totally baffled by it ever even being brought up.

[Terry Beadle]

My apologies to Mr. Pan. It was Tri Hoang's comments I was referring to. I've read Mr. Pan's comments so often as being good advice I some times bite my toes as I cram my foot in my mouth.

Derek,

I'm not sure I got side tracked or just was not clear in my advice. Unfortunately, the results are the same. Thank you for your patience.

In my own defense, I was thinking of David Charlesworth's recommendations of using back bevels on BD smoothers that resulted in 65 degree final edge angles. On a BD plane a wear burr is a different problem than tough wood grain. Doing a back bevel on a BD plane probably would not solve the wear burr as it would occur any way. Mr. Charlesworth also states that you must take less than 2 thou shavings for these back bevels to work weather it's using a BD or BU plane. Using the ruler trick or just honing the flat are both solutions to getting rid of the wear burr.

I think your comment that it's probably a steel issue is right and the planes he's talking about in the OP are very new.

I'm going to go stand on my head a while and think about it...that will give me an Australian's view of the problem and probably cure my faulty thinking...hoot!

Thanks again for your clarity !

[Wilbur Pan]

My apologies to Mr. Pan. It was Tri Hoang's comments I was referring to. I've read Mr. Pan's comments so often as being good advice I some times bite my toes as I cram my foot in my mouth.
I'm always happy to be confused with someone giving sound advice, as Tri Hoang did. ;) Actually, Tri should be mad that he was confused with a chucklehead like myself.

Here's an interesting statement that I found today when goofing off at work. It's from From The Wooden Plane: Its History, Form, and Function, by John Whelan (http://homepages.sover.net/~nichael/nlc-wood/chapters/caop.html):


Although softwoods permit a smaller sharpening angle, they also yield more before being cut and thus require a larger clearance angle.

Although no numbers were given to quantify what was mean by "larger clearance angle", I'm extrapolating this to mean that harder woods benefit from larger sharpening angles (not a controversial statement), and we can get away with lower clearance angles with these species.

This may explain why Derek hasn't seen wear bevel and clearance issues when working with the hard Australian species that he uses, while people (myself included) working with North American species, including softer hardwoods and pines, find this to be more of an issue.

[David Keller NC]

A very fine edge at 25 degrees has got to be rather fragile. Therefore it would seem to me that reducing the finess of entry while still maintaining sharpness ought to greatly reduce - but not fully eliminate - this problem.

Harvey - It's worth mentioning here that the included cutting angle when the blade is in the plane is somewhat meaningless as far as edge fragility. The edge of an iron ground at 25 degrees is more fragile than one ground at 30 or 35 degrees, regardless of the bed angle of the plane it's being put into. This isn't 100% true - an iron used at 90 degrees in a scraper plane will wear or spall faster than the same iron used at 45 degrees, but a 25 degree bevel is going to put a lot of stress on the cutting edge regardless.

You also don't say whether the plane is a L-N or L-V and whether the blade is the same make (presumably so if the planes are new). If you're planing rosewood (cocobolo especially), I'd say that you're going to need an incredibly hard iron - an American made Hock may be your only recourse, because IMO cocobolo is about as hard as granite.

If instead you're planing purple heart, ebony, yellow heart, and other common tropical species, I'd suggest that you've probably gotten a bum batch of blades that are too soft. And if they're L-V or L-N, a replacement is a phone call away.

[Harvey Pascoe]

Today I leveled and smoothed a thick veneer of masur birch set as a panel in a frame of Ziricote, both nasty wood to plane. I used 3 planes in a test: LN102 25*BU; LV standard BU block w/25* blade, and LV smoother w/38* blade. Both the LV planes did the job well but the 38* blade showed no ill effects from a lot of hard work as I took down about 3/32 very slowly to avoid tear out. But the 25* blade viewed with magnifying glass reveals very minor edge chipping or galling, enough that I can feel it when I run my fingernail along the edge. The LN 102 proved too small to be effective.

There was definitely a wear bevel on the under side of the blade. Minute, but visible. I knocked this off by putting a slight back bevel of perhaps .005" and retested it. After ten minutes of working, took it out and inspected. Edge galled again. I think Derek is right, 25* is too fine an entry for wood this tough, so I will order a 38* blade for this plane as well.

I will also try adding a higher angle back bevel and see how that goes. I drew this out on paper and it seems to me that there is a favorable change in geometry as far as edge strength goes and I don't see why this should adversely affect the cutting angle so long as the bevel angle remains negative to the sole. If the edge still galls, then I will know I got a bum blade for sure.

That make sense?

[Tri Hoang]

I'm a fan of the BU planes. My initial push into this slippery slope was by the BU jack from Veritas. I like them so much that I had a fleet of 6 at one time. It's down to 4 now. Wear bevel has always been an issue for me until I started making an effort to minimize it.

The first thing I did was to take lighter cuts. The second thing I did was to strop the face (back) of the iron more often to keep the edge fresh. Lastly, I re-sharpened sooner than I would on a BD plane & spent more time on the face.

I don't doubt that some never experience wear bevel on these but I'm certain it's there on my blades every time I resharpen them. Therefore, I felt like I have to say something about it. I'm not a fan of the ruler trick as I believe there is no free lunch. It does not mean that it won't work for someone else.

[Jim Neeley]

I will order a 38* blade for this plane as well.


Harvey,

With a BU plane, there's no need to order a new blade; just regrind it. If you just regrind enough of the bevel to avoid the roll-under, it'll be easier to sharpen than a full 38* beveled blade.

Jim

[David Weaver]

I'm not a fan of the ruler trick as I believe there is no free lunch.

Not necessarily free, more like reduced price.

All of the efforts sound like ...well, lots of extra efforts. Presumably these planes are not being used on rough boards or leveling boards way out of whack?

I see the wear bevel on mine before I clean it off, it's there, but take a look at a BD iron any time you have clearance similar to the BU plane - the same wear bevel is there, it's just on the bevel side. A plane will cut fine despite the visible abrasion/adhesion marks on the metal, and there's no reason to really worry about it until it's affecting performance.

Caveat, of course, anyone can do anything they want to in their shop, just my opinion.

[Harvey Pascoe]

Harvey,

With a BU plane, there's no need to order a new blade; just regrind it. If you just regrind enough of the bevel to avoid the roll-under, it'll be easier to sharpen than a full 38* beveled blade.

Jim

Duh, hadn't thought of that, but I just discovered that they don't make a 38 for the LV standard block, so to the grinder I go.

Are there some woods that just are not planable no matter what you do? Ziricote seems to be one, cocobolo another which I get that tiny tear out no matter what I do. One of the reasons I'm still in first grade on hand planes is that I learned how to hone my jointer blades to 4,000. There is nothing I can't run over it with zero tear out. However, my hands can no longer take working a scraper for 15 minutes to remove chatter marks, so back to hand planes. Where I really run into trouble is truing up and smoothing small veneered panels with difficult grain. I still find myself turning to the flatbed sander for these problems.

[Andrew Hughes]

Yes Harvey some woods just refuse to be hand planed.Some of the ones i have come across are teak, bulbinga,cocobolo even redcedar has sand in it.Sometimes ya just got put the planes back in the drawer put on a fresh pot of coffee.And prepare a card scraper.And maybe get some paper with sand glued on it. Good luck Andrew

[Harvey Pascoe]

Harvey - It's worth mentioning here that the included cutting angle when the blade is in the plane is somewhat meaningless as far as edge fragility.


You also don't say whether the plane is a L-N or L-V and whether the blade is the same make (presumably so if the planes are new). If you're planing rosewood (cocobolo especially), I'd say that you're going to need an incredibly hard iron - an American made Hock may be your only recourse, because IMO cocobolo is about as hard as granite.

Yeah, I know the total angle means nothing insofar as the fragility of the edge.

I came to the conclusion that 25* is way too little for these hard woods. As a kid I worked as a machinist, so I learned a bit about cutting edge geometry but I simply forgot. On testing I found that putting a back bevel on alleviates the problem entirely with NO degradation of performance. A back bevel strengthens the edge, and since I'm mostly smoothing and not doing end grain, this is the way to go for me. As long as there is adequate relief on the underside of the blade it will cut hardwood not only well, but better than without the relief since the edge is not diving into the wood, then tearing hunks out.

I'm not blaming the blade, it holds the edge when reconfigured. I think most of these guys objection to back bevels has to do with shooting end grain. BTW, if you draw this out on paper at a 10:1 scale you will get a much better idea of what is happening with various angles and bevels.

[Harvey Pascoe]

Yes Harvey some woods just refuse to be hand planed.Some of the ones i have come across are teak, bulbinga,cocobolo even redcedar has sand in it.Sometimes ya just got put the planes back in the drawer put on a fresh pot of coffee.And prepare a card scraper.And maybe get some paper with sand glued on it. Good luck Andrew

Andrew, that makes me feel better! I honed my jointer knives to 4000 and it will plane anything perfectly, so I reason if the jointer can do it, why can't I? Well, the hand plane is not rotary, that's why. I must be doing okay because I can do teak okay and bubinga, even waterfall bubinga if I'm careful. But coco? No way. Many of the rosewoods pose real problems, they'll plane fine untill the grain changes direction then it rips out 1/8" divots and no scraper is going to get rid of that.

So why do it the hard way when I can use the jointer, LOL.

[Derek Cohen]

It is rare that I resort to sandpaper. Just increase the cutting angle of your smoother. I commonly use 60-62 degrees on Jarrah, Karri, She-Oak, etc here in Australia. Sometimes I hone the blade at 65-70 degrees. If this fails, then I go to cabinet/card scrapers. The typical hardwoods I work tend to fail on anything below 55 degrees.

The widest bevel up LV plane blades are 2 1/4". These are easy enough to push at these included angles. The BU Smoother is superb, but I prefer the feedback of the smaller 2" wide LA Smoother. The new and narrower Small LA Smoother should be the easiest of all at these angles (not used one). This is the particular strength of BU smoothers. The highest bed angle currently in a LN bevel down plane is 55 degrees (without resorting to a backbevel to increase this further). I have a 55 degree frogs in LN #3 and #4 1/2 bronzes. These are reserved for less interlocked grain. If LN do eventually produce a 60 degree frog, I would not consider it for the 2 3/8" wide blades - these would be too difficult to push. The smaller #3 and #4, however, should work well.

Regards from Perth

Derek

[David Weaver]

The woods that can't be planed are the ones that are soft or have soft elements (between the rings on quartered figure, etc) in them and are all over the place. The hard ones are generally OK if you figure out what to do with them, because they will tolerate a higher angle and have enough strength to stand up to a plane iron and be sheared off.

Cocobolo and other stuff like it can be planed fairly easily if you have a sharp plane (you'll probably have to sharpen a lot, especially if you see glints of silicon in the wood as you plane it), light cut, very tight mouth, and good fit with all of the components in the plane so that nothing is moving or chattering. Somewhere around the 55 degree point that derek mentions is the sweet spot for those woods, steeper than that, and the plane feels like pushing a scraper and the edge life quickly gets shorter and the surface will look more dull as the angle increases, even with a sharp iron. "can be planed" is somewhat subjective, too - you will have areas around knots, etc, where planing will leave you with spots that blotch in finish where the grain changes directions, but there is no tearout. See what you can live with - you should be able to do without having tearout that goes beyond that.

In the US, you shouldn't need anything steeper than 55 degrees to do what you need to do, just keep the mouth very tight to avoid tearout that can't be removed easily (you won't get long gouges with a 5 thousandth mouth). If that doesn't do the job, then sand it and card scrape it afterward if you want a hand-done look. There is a level of reasonability to go with, there's no great reason to spend 3 hours to smooth plane a surface, only to tearout on your last pass and resort to sandpaper - unless you're making furniture for sale and the buyer specifies that.

If you're not sure if something can be planed, tighten the mouth, lighten the cut, sharpen the iron, and plane the wood in every direction you can to see what it tolerates well, it's not always intuitive, no matter how much experience you have. Skew the plane as you're planing, etc, try different things. Increase the effective pitch if that doesn't quite do it but you're close.

[Derek Cohen]

If you're not sure if something can be planed, tighten the mouth, lighten the cut, sharpen the iron, and plane the wood in every direction you can to see what it tolerates well, it's not always intuitive, no matter how much experience you have. Skew the plane as you're planing, etc, try different things. Increase the effective pitch if that doesn't quite do it but you're close.

Good points David.

For the mixed hard and soft striated woods (like ribbon mahogany), plane across the grain.

Regards from Perth

Derek

[Harvey Pascoe]

It is rare that I resort to sandpaper.

I hope to get to that point, Derek, just as soon as I get up the nerve to try to put a curve on my blade edges or round the corners. This morning I just trued up a large block of very hard maple burl using 38* blades in both the standard block BU and the 9" LA smoother. After honing the blades on 0.5 micron paper, equal to about 10,000 grit, I was amazed at how easily and well they did the job, easy enough that I did it sitting down on a wheeled draftsmans chair. Then I put them to the test on some spalted maple with significant rot, fully expecting to see some terrible tear out on punky wood. Wrong, it handled that magnificently.

I've been most surprised at how versatile this heavy little block plane is and the multiple tasks it can handle. No wonder I didn't like that big heavy LA jack with wide blade; it was just too big for me.

[Bill Rittner]

The wear bevel is more profound when the BU planes are used on abrasive/hard/dense wood as well as when taking thicker shavings. So if you can't avoid those kinds of wood, take lighter cuts. If you are using the Veritas BU planes, get their M2 HSS blade for more abrasive wood. I could not get the M2 HSS as sharp as A2/O1 on my stones but it's sharp enough and loooooong lasting.

Where are you finding M2 HSS blades for the Veritas BU planes? I just looked at the Lee Valley site and could not find them.

[David Weaver]

Call LV if you want them, I believe they'll sell them if you request them, even though they're not listed. IIRC, they weren't charging much (any?) premium for them, which is refreshing given the price of all but the muji HSS irons that are already out there.

[Tri Hoang]

Where are you finding M2 HSS blades for the Veritas BU planes? I just looked at the Lee Valley site and could not find them.

Call/email Lee Valley. The part # for the 38* M2 HSS 2-1/4" blade is 05P3463. I'm not sure about the performance of these M2 HSS blades at lower cutting angles (i.e. less than 35*) due to potential chipping. For end grain shooting, I'd stick with O1/A2.

[Joel Goodman]

so to the grinder I go.

Just hone a microbevel (not a back bevel) at a higher angle-- no need to use the grinder at all. I would try 30 and if still some issues then 35 degrees and see how it works. It takes very little time to increase the microbevel angle. Also if the irons are new the very end sometimes has heat treatment issues and it will improve as that is honed or ground away.

[Harvey Pascoe]

David, thanks for the advice. The problem I have is that I work with stock size only 3" wide so its kind of tough planing across the grain. I do skew a lot but I may not have the throat closed enough so I closed it to 1/32". Working with a straight grained piece and using a block plane for greater control, I managed to get a perfect result. On a figured piece, I still got that slight fuzzing along the reversing grain but not so much that it can't be eliminated with a few strokes of my wing handle scraper.

BTW, the block plane is 12 + 35* for total angle of 47*.

I have become highly allergic to cocobolo so its imperative that I eliminate dust from sanding. Plus, I put a mirror finish on it with varnish (yeah, I do varnish coco) so the more perfect I get the surface without sanding/ filling, the better. This seems to do the trick, so thanks for your advice.

Next I tried this on a piece of bocote and it was a total failure, ripped out big chunks no matter what I did. So screw that, make life easy and just run it over the jointer and scrape away the chatter :-)