The Concave Cambered Blade

[matthewwh]

Two questions:

Are you using waterstones to hone the iron?

Is the centre of the cutting edge still reasonably sharp?

If the answer to either of the above is yes then you may wish to check the flatness of your stones first. The friable surface of a waterstone will, over time, deform to the shape of the blade it is honing. So if you are doing a lot of edge jointing without flattening your stones regularly, they will allow a profile like the one you have to develop - the edge will still be sharp so you don't necessarily notice until the cutting performance of the tool changes. Other stones will do the same thing eventually but is more common with waterstones.

If you believe that the iron is at fault, I will be happy to replace it for you (with one that I have already cambered and polished if you prefer). A Clifton iron should cut rings around anything else on the market so I'll send it back to Sheffield and have it checked out by the engineers at Clico and report back to the forum.

 

[adrian]

Two questions:

Are you using waterstones to hone the iron?

Is the centre of the cutting edge still reasonably sharp?

If the answer to either of the above is yes then you may wish to check the flatness of your stones first. The friable surface of a waterstone will, over time, deform to the shape of the blade it is honing. So if you are doing a lot of edge jointing without flattening your stones regularly, they will allow a profile like the one you have to develop - the edge will still be sharp so you don't necessarily notice until the cutting performance of the tool changes. Other stones will do the same thing eventually but is more common with waterstones.

I have not directly tested how sharp the center of the edge is. Note, however, that if I look at the edge I can see a glint indicating that some sort of rounding over or edge failure has occurred in the centre region. (I used the plane for a long time since the last honing so it would be surprising if it was really sharp.)

I am using Shapton ceramic stones. I flatten them often, usually after finishing each blade I hone.

I have two responses to this, a sort of theoretical one and a pratical one.

Theoretical:

Based on what people here have said, the shape of a blade should not change significantly in use unless something is wrong with the blade (e.g. it's not hard enough). So even if I'm just working on edges, I should keep the same blade shape. This means that if I take bad care of my water stones, the stones will become concave not because they matches the shape of the blade, but because I tend to use the middle of the stone more than the edges as I hone. This concavity will then give rise to a convex, cambered edge. (I did, in fact, spend years using insufficiently flat water stones for sharpening and it made the task extremely frustrating.) But unless I made a practice of working only the periphery of my stones, I don't see how they could turn convex as required to produce the profile exhibited by the blade.

Practical:

This is not something that has been happening gradually as the stones wear and I hone and rehone. Each time I have ground the camber back onto the blade and each time, when the plane stops working properly it does so without going anywhere near a stone. The pattern of use is that the plane works properly for quite a while and then I suddenly notice that it's cutting at the edges instead of in the center.

Unfortunately I don't have a "before' picture to show the blade profile that I started with, but there was a single contact point in the center of the blade and the blade would rock on my straight reference. (I used a wooden straight reference to avoid damaging the edge when I did this final check.) Now the plane contacts the straight reference in two points and does not rock.

If you believe that the iron is at fault, I will be happy to replace it for you (with one that I have already cambered and polished if you prefer). A Clifton iron should cut rings around anything else on the market so I'll send it back to Sheffield and have it checked out by the engineers at Clico and report back to the forum.

I honestly don't know what to believe at this point. The theory that the blade is just too soft seems to be weakened by the scratch testing. You think a Clifton iron should perform better than an A2 iron?

The possible explanations I see at the moment are

1. Something is wrong with the blade (it's too soft or otherwise flawed)

2. Maybe my bevel angle is to blame

3. Maybe I'm doing something bad to the blade just occasionally and as luck would have it, I've only done the bad thing while using the Clifton.

I'm at a loss to decide which one it is. Do you think it's the blade? I was leaning towards getting a Veritas replacement blade (which costs half as much as the Clifton, at least here in the USA) and see if the problem recurs. (This blade would presumably have identical metallurgical properties to the blade in my other planes that have not exhibited this problem, so that would control for blade composition.) If I took you up on your generous offer to trade blades, I must note that it might be a long time before I'd be able to report on the performance of the new blade because I've finished almost all of the jointing for the project at hand and I'm moving on to the joinery, so I won't be doing much edge jointing for a while, possibly several months. (And actually the next jointing job will be on curly wood which might not respond well to the 45 degree cutting angle of the clifton.)

 

[matthewwh]

I used the plane for a long time since the last honing so it would be surprising if it was really sharp.

That may well be the root of the problem. If you are just working one part of the blade then you will naturally get wear on that part and not the rest. If the blade is fully engaged the wear will be consistent and although the edge will dull, the edge shape will not alter. You should sharpen as soon as you feel the performance start to drop off, because a sharp edge will wear less quickly than a dull one.

Bevel angle may also be an important factor. The famed longevity of A2 blades has more to do with the fact that it has to be bevelled at 35 degrees in order to remain cohesive than the physical wear resistance of the steel (6% or so higher than O1).

Each Clifton iron is individually hand forged from a 4-1/2lb round bar of O1 carbon tool steel. Their primary reason for using this material is its capacity to take a superior edge and therefore produce the finest surface possible on the timber. It has much better cohesive properties than A2 and can therefore be ground at low angles, so they install a 25 degree primary bevel as standard because lower angles produce a sharper edge. Adding a secondary bevel at a higher angle will increase wear resistance substantially.

the next jointing job will be on curly wood which might not respond well to the 45 degree cutting angle of the clifton.)

A 5 or 10 degree micro back bevel on your Clifton blade will allow you to change the effective pitch of the plane. I have surfaced loft matured, heavily burred, English oak successfully with a Clifton 4-1/2 using this method. Until I tried it I would have sworn that nothing short of an infill would touch the stuff. Again, for consistent results you need to be in the habit of touching the edge up as soon as you feel the performance diminish though. Lower angles for timbers with prominent medullary rays or other inconsistencies of hardness can be achieved by skewing the plane to the work.

I have recently taken to honing my blades on a powered polishing mop with green polishing compound as an automated alternative to stropping. I can now go from dropping the blade out to taking the next shaving in 90 seconds flat, including curved blades, with a visit to the stones (glass in my case) for a proper sharpening once for every 6-8 stroppings. This reduced effort has made me much more active in feeling for the performance change, maybe even anticipating it, rather than trying to squeeze a few more shaving from a dull blade.

I hope all this helps, if not the offer still stands. I am a fully paid up Clifton dealer and take the role of product support just as seriously as I do the supply of new tools (to be honest, I'm very surprised that your local dealer isn't interested in helping to resolve your issue.)

 

[Aled Dafis]

I have recently taken to honing my blades on a powered polishing mop with green polishing compound as an automated alternative to stropping. I can now go from dropping the blade out to taking the next shaving in 90 seconds flat, including curved blades, with a visit to the stones (glass in my case) for a proper sharpening once for every 6-8 stroppings. This reduced effort has made me much more active in feeling for the performance change, maybe even anticipating it, rather than trying to squeeze a few more shaving from a dull blade.

Matthew

Care to expand on this method? Is it something I could rig up in my woodturning lathe, seeing as it gets very little use when I'm doing flat work? As usual, it never happened unless there are pics to prove it :wink:

Cheers

Aled

P.S. What bevel angle is normally supplied on the new AI chisels, I seem to remember reading recently that it was around 23deg, which sounds about right, but I have a feeling that mine are substantially higher at around 30deg - I've not measured them, so I cant give an accurete measurement. It's no problem for me to regrind them, but I was just wandering, as it seems a little high to me.

My first impressions are that they're GOOD!!! they feel much nicer to handle than my LN's, and polishing the backs only took me a couple of minutes on my 8000 grit Norton stone.

 

[matthewwh]

Hi Aled,

I just measured a couple (computer in the workshop - brilliant idea!) and one came out at 22.5 and the other at 24 (approximated using one of Mr Kell's magic devices) so the current batch are a tad under the 25 which is what we wanted.

Regarding the mechanised stropping thing, yes it can be mounted in a lathe. All the goodies are on the mechanised sharpening page in the sharpening section of the website. I'll tidy up the metalwork bench and post some photos as soon as I get a chance.

 

[Aled Dafis]

Hi Aled,

I just measured a couple (computer in the workshop - brilliant idea!)

At this time of night, in this weather? are you mad?

Thanks for your reply however, this confirms what I initially thought.

Cheers

Aled

 

[adrian]

I used the plane for a long time since the last honing so it would be surprising if it was really sharp.

That may well be the root of the problem. If you are just working one part of the blade then you will naturally get wear on that part and not the rest. If the blade is fully engaged the wear will be consistent and although the edge will dull, the edge shape will not alter. You should sharpen as soon as you feel the performance start to drop off, because a sharp edge will wear less quickly than a dull one.

Yes, well, I'm still not very good at distinguishing a sharp blade from a sort of sharp blade, so I'm undoubtedly going longer between honings than is optimal. However, the plane was taking reasonably nice shavings up until the end. (Or, at least I thought they were OK.) American Cherry is a very easy material to work except that I do have some tiny knots and grain reversals on some of the edges.

When I first posted about this issue, people seemed to think that I should not lose my camber in use, that this amount of wear could not occur, despite the use of only the blade center. I mean, it's obvious that the wear is all going to be in the center. But how much wear will occur or can occur? I personally have no deep knowledge of metallurgy to say whether the amount of wear I'm observing is normal or unusual. Suppose you used a plane blade for edge planing 10 times longer than you should (e.g. you should have honed it ten times but you just kept on working). Would you expect to wear away the center of your camber?

Where does the metal go? If we are talking about rounding over and deforming the edge that's a lot of metal to round over, isn't it?

I find it troubling because it takes me a long time to reestablish the camber once this happens.

Bevel angle may also be an important factor. The famed longevity of A2 blades has more to do with the fact that it has to be bevelled at 35 degrees in order to remain cohesive than the physical wear resistance of the steel (6% or so higher than O1).

You mean people who compare A2 and O1 are not doing it at the same bevel angle? (Veritas sells their blades A2 and O1 blades with identical bevels.) Do you think than an A2 and O1 blade sharpened both at 30 degrees should exhibit fairly similar longevity?

Each Clifton iron is individually hand forged from a 4-1/2lb round bar of O1 carbon tool steel. Their primary reason for using this material is its capacity to take a superior edge and therefore produce the finest surface possible on the timber. It has much better cohesive properties than A2 and can therefore be ground at low angles, so they install a 25 degree primary bevel as standard because lower angles produce a sharper edge. Adding a secondary bevel at a higher angle will increase wear resistance substantially.

I know I had raised the angle on the Clifton at least to 27 and possibly up closer to 30. I think the A2 blade in my other plane has an angle around 30, maybe 31 or 32 with the microbevel.

the next jointing job will be on curly wood which might not respond well to the 45 degree cutting angle of the clifton.)

A 5 or 10 degree micro back bevel on your Clifton blade will allow you to change the effective pitch of the plane.

I'll admit that I've been reluctant to back bevel because it seems that it would makes sharpening more complicated---the last thing I need is something that discourages me from honing. I noticed that Charlesworth recommends a 25 degree (!) back bevel in his latest DVD. (But I haven't actually watched that part yet.) Do you see some advantage to using a back bevel on a bevel down plane compared to a bevel up plane sharpened at a higher angle?

I hope all this helps, if not the offer still stands. I am a fully paid up Clifton dealer and take the role of product support just as seriously as I do the supply of new tools (to be honest, I'm very surprised that your local dealer isn't interested in helping to resolve your issue.)

Thanks again for this offer. I think the basic question is whether the problem results from flawed technique or a flawed blade. From what I've posted so far, where do you think the problem lies?

If O1 steel has properties that make it less forgiving of infrequent honing and more subject to wear under these circumstances, perhaps there's nothing wrong with the blade at all and the observed wear is normal for my use. A new blade would do exactly the same thing. I might be better served in this case by either improving my technique (honing more often) or getting a different kind of blade. Perhaps I should reserve the O1 blade for work with a straight edge and get an A2 blade to camber. (Or I found that a D2 blade is available as well. I have no idea how D2 compares to A2.)

 

[matthewwh]

Yes, well, I'm still not very good at distinguishing a sharp blade from a sort of sharp blade, so I'm undoubtedly going longer between honings than is optimal. However, the plane was taking reasonably nice shavings up until the end. (Or, at least I thought they were OK.) American Cherry is a very easy material to work except that I do have some tiny knots and grain reversals on some of the edges.

A properly sharpened blade should produce a clean polished surface on cherry regardless of small knots and reversals. If you see any fluffiness in the surface or the plane feels more difficult to push, then it's time to strop or sharpen.

When I first posted about this issue, people seemed to think that I should not lose my camber in use, that this amount of wear could not occur, despite the use of only the blade center. I mean, it's obvious that the wear is all going to be in the center. But how much wear will occur or can occur? I personally have no deep knowledge of metallurgy to say whether the amount of wear I'm observing is normal or unusual. Suppose you used a plane blade for edge planing 10 times longer than you should (e.g. you should have honed it ten times but you just kept on working). Would you expect to wear away the center of your camber?

As a blade dulls there is more friction and therefore more wear. In normal use on a flat surface you wouldn't notice how much has worn away as you have nothing to compare it with. Although it looks quite dramatic when you hold it up to a straight edge, you have probably only gone a few thou below flat on the centre of the cutting edge.

Where does the metal go? If we are talking about rounding over and deforming the edge that's a lot of metal to round over, isn't it?

You can see the same thing happening more clearly when you are sharpening, (which is really nothing more than controlled intentional wear). The steel forms a tiny burr or wire edge on the trailing edge of the tool which then breaks away. With correctly hardened steel the burr is incredibly small and breaks away effortlessly. With unhardened steel it forms a large flap that won't come off until you tear it.

I find it troubling because it takes me a long time to reestablish the camber once this happens.

A good reason to use a flat grind when doing a lot of edge jointing, this will also allow you to use more of the width, thereby evening out the wear on both the blade and the sole.

You mean people who compare A2 and O1 are not doing it at the same bevel angle? (Veritas sells their blades A2 and O1 blades with identical bevels.) Do you think than an A2 and O1 blade sharpened both at 30 degrees should exhibit fairly similar longevity?

Words like "can last up to" indemnify marketers from the usual rules of scientific best practice I'm afraid. That said, A2 does undoubtedly have better wear characteristics than O1. The difference however comes at the price of edge taking ability, O1 is a doddle to sharpen to a superfine edge.

Imagine a truck full of rocks tipping its load, the finest edge you can get on the back is one rock thick. In comparison O1 is like fine sand with 0.5% rocks, A2 is like fine sand with 5% rocks and depending on how many times it has been tempered a certain amount of gravel. For the more metallurgically minded read sand = martensite, Rocks = chromium content and gravel = austenite.

I know I had raised the angle on the Clifton at least to 27 and possibly up closer to 30. I think the A2 blade in my other plane has an angle around 30, maybe 31 or 32 with the microbevel.

If you were about to start an edge jointing marathon and were more concerned with wear resistance than surface finish I'd put at least a 38 degree secondary bevel on either type of steel.

I'll admit that I've been reluctant to back bevel because it seems that it would makes sharpening more complicated---the last thing I need is something that discourages me from honing. I noticed that Charlesworth recommends a 25 degree (!) back bevel in his latest DVD. (But I haven't actually watched that part yet.) Do you see some advantage to using a back bevel on a bevel down plane compared to a bevel up plane sharpened at a higher angle?

It's the same thing really, all you are doing is changing the effective pitch of the tool (the angle between the surface of the timber and the first bit of blade that it picks up on). Effective pitches fall into three broad categories: high, common and low. There are names for individual pitches like 'York' 50, 'Cabinet' 60, but don't worry about that for now. The basic principles are as follows: For knotty, highly figure timber use a higher pitch. For timber where there are large differences in hardness within the timber - lace she-oak or zebrano for example - or for endgrain use a lower pitch. For everything inbetween use common pitch (45 degrees). Personally I keep a spare blade that will fit either my 6 or my 4-1/2 honed with a 10 degree microbevel on the back for the tricky stuff. I can swap it out at a moments notice and I don't have to monkey about regrinding the blade every five minutes.

Thanks again for this offer. I think the basic question is whether the problem results from flawed technique or a flawed blade. From what I've posted so far, where do you think the problem lies?

If O1 steel has properties that make it less forgiving of infrequent honing and more subject to wear under these circumstances, perhaps there's nothing wrong with the blade at all and the observed wear is normal for my use. A new blade would do exactly the same thing. I might be better served in this case by either improving my technique (honing more often) or getting a different kind of blade. Perhaps I should reserve the O1 blade for work with a straight edge and get an A2 blade to camber. (Or I found that a D2 blade is available as well. I have no idea how D2 compares to A2.)

No problem using an O1 iron with a camber at all but to benefit from its qualities you must keep it honed.

D2 is like A2 on steroids, it has 11-13% Chromium (rocks) content so it takes an edge like a baby's backside and holds onto it forever. Great for things like survival knives where you can spend hours trying to get it reasonably sharp but may need to use it for weeks on end without the facility to resharpen it.

If you are truly averse to honing you might consider HSS (high speed steel) blades if you can find them. HSS will take a reasonable edge and has excellent wear resistance. It is a monumental pain to hone (nigh on impossible by hand) but it will get there eventually.

 

[adrian]

Yes, well, I'm still not very good at distinguishing a sharp blade from a sort of sharp blade, so I'm undoubtedly going longer between honings than is optimal. However, the plane was taking reasonably nice shavings up until the end. (Or, at least I thought they were OK.) American Cherry is a very easy material to work except that I do have some tiny knots and grain reversals on some of the edges.

A properly sharpened blade should produce a clean polished surface on cherry regardless of small knots and reversals. If you see any fluffiness in the surface or the plane feels more difficult to push, then it's time to strop or sharpen.

If this is really true then I never had a `sharp' blade. I had one particularly troublesome grain reversal where I specifically went and honed the blade but I still got some tendency to tear out one one side or the other. (This one had had a 5 mm knot in it which I had extracted and filled.)

I was recently having some difficulties with tear out again and I switched to a blade with an effective pitch of 62 degrees and it was much better.

I have successfully planed curly maple with my bevel down bench planes without tear out. (The shavings had to be under 2 thou or I'd start getting tear out.) So I think I actually am achieving sharp blades.

When I first posted about this issue, people seemed to think that I should not lose my camber in use, that this amount of wear could not occur, despite the use of only the blade center. I mean, it's obvious that the wear is all going to be in the center. But how much wear will occur or can occur? I personally have no deep knowledge of metallurgy to say whether the amount of wear I'm observing is normal or unusual. Suppose you used a plane blade for edge planing 10 times longer than you should (e.g. you should have honed it ten times but you just kept on working). Would you expect to wear away the center of your camber?

As a blade dulls there is more friction and therefore more wear. In normal use on a flat surface you wouldn't notice how much has worn away as you have nothing to compare it with. Although it looks quite dramatic when you hold it up to a straight edge, you have probably only gone a few thou below flat on the centre of the cutting edge.

Of course it's only a few though, probably less than 2. I suppose I could test it with feelers. The original camber might have put the center 3 thou above the current high points. (I was aiming for the Charlesworth suggested camber of 0.25 mm = .01in at the sides.) So that means that I've lost 4-5 thou at the edge center. Do you think this is a normal amount of wear? (In other words, it doesn't indicate some sort of blade defect, as others have suggested.)

To provide a bit more information on how long I went without honing: the last time this happened had sharpened my planes and subsequently jointed 68 linear feet of edge. I then fine tuned the edges, taking a few more shavings off 48 linear feet. And at that point I noticed the same concave edge on the Clifton blade. When I did this I had a jack plane set for a thicker shaving and then I would finish up with the Clifton jointer set for a fine shaving.

Where does the metal go? If we are talking about rounding over and deforming the edge that's a lot of metal to round over, isn't it?

You can see the same thing happening more clearly when you are sharpening, (which is really nothing more than controlled intentional wear). The steel forms a tiny burr or wire edge on the trailing edge of the tool which then breaks away. With correctly hardened steel the burr is incredibly small and breaks away effortlessly. With unhardened steel it forms a large flap that won't come off until you tear it.

So the wear process in use is abrasion, just like on the stones? (It would be different because the blade would wear on both the front and back of the blade, so you'd never get a burr.)

I find it troubling because it takes me a long time to reestablish the camber once this happens.

A good reason to use a flat grind when doing a lot of edge jointing, this will also allow you to use more of the width, thereby evening out the wear on both the blade and the sole.

But I have not been successful at edge jointing with a flat blade. I'm not using the cambered blade just for the sake of complication.

In fact, in case of the above mentioned 62 degree high angle blade, the blade was actually one of the few flat blades I have left when I decided to try it on the cherry that was tearing out. And in a few strokes it became apparent that without the camber I was in trouble. The wood was getting less and less square and I couldn't seem to correct it. (Note that in this case, I'm planing a final outside edge, so it needs to be actually square, not just cut at the same angle as its mating board in a panel.)

I went and cambered this blade. Actually I got an overly aggressive camber I'm having trouble fixing where I can only get a 1/2 inch shaving. But even so, I was able to do the job with too much camber far better than with the straight blade.

I know I had raised the angle on the Clifton at least to 27 and possibly up closer to 30. I think the A2 blade in my other plane has an angle around 30, maybe 31 or 32 with the microbevel.

If you were about to start an edge jointing marathon and were more concerned with wear resistance than surface finish I'd put at least a 38 degree secondary bevel on either type of steel.

At least 38 degrees? That means the angle of the bevel with the workpiece is 7 degrees or less. I thought you had to have a "relief angle" of 10 degrees or something like that. (It's been a while since I read Lee's book.)

I'll admit that I've been reluctant to back bevel because it seems that it would makes sharpening more complicated---the last thing I need is something that discourages me from honing. I noticed that Charlesworth recommends a 25 degree (!) back bevel in his latest DVD. (But I haven't actually watched that part yet.) Do you see some advantage to using a back bevel on a bevel down plane compared to a bevel up plane sharpened at a higher angle?

It's the same thing really, all you are doing is changing the effective pitch of the tool (the angle between the surface of the timber and the first bit of blade that it picks up on).

So there's absolutely no difference between a bevel up plane beveled to deliver a cutting angle of X and a bevel down plane back beveled to give a cutting angle of X? Presumably for lower angles there must be an advantage to the bevel down plane on account of the chip breaker.

Thanks again for this offer. I think the basic question is whether the problem results from flawed technique or a flawed blade. From what I've posted so far, where do you think the problem lies?

If O1 steel has properties that make it less forgiving of infrequent honing and more subject to wear under these circumstances, perhaps there's nothing wrong with the blade at all and the observed wear is normal for my use. A new blade would do exactly the same thing. I might be better served in this case by either improving my technique (honing more often) or getting a different kind of blade. Perhaps I should reserve the O1 blade for work with a straight edge and get an A2 blade to camber. (Or I found that a D2 blade is available as well. I have no idea how D2 compares to A2.)

No problem using an O1 iron with a camber at all but to benefit from its qualities you must keep it honed.

Didn't you just suggest using a straight blade instead of a cambered blade a few paragraphs up? The point of the above analysis is not to state great truths about blades and steels, but to decide what I ought to do with my Clifton plane. If the failure of my blade seems extraordinary, then it makes sense to take you up on your offer to swap. But if not, then I should instead figure out the best way to make use of the blade. Sharpening it flat would presumably prevent the problem of having to constantly recamber it, so that's one possibility. Exercising the discipline to hone more often is perhaps another solution.

D2 is like A2 on steroids, it has 11-13% Chromium (rocks) content so it takes an edge like a baby's backside and holds onto it forever. Great for things like survival knives where you can spend hours trying to get it reasonably sharp but may need to use it for weeks on end without the facility to resharpen it.

Does this mean it would give an inferior finish to A2?

If you are truly averse to honing you might consider HSS (high speed steel) blades if you can find them. HSS will take a reasonable edge and has excellent wear resistance. It is a monumental pain to hone (nigh on impossible by hand) but it will get there eventually.

I think I prefer a middle ground. If I had a blade that was a monumental pain to hone I'd probably never sharpen it.

My reluctance to hone as often as I should has, I think two origins. One is that all too often, at least in the past, it has seemed to require 45 minutes. I typically only get 45 minutes at a time to work on my project at all. Sometimes I only get 10-15 minutes. Now I can report that I recently honed a blade in only 5 minutes, so things have improved. Part of my problem in the past was dished waterstones. I would sharpen for eons and never get a burr that went all the way out to the corners, presumably because the back of the blade was convex. Now the problems seem to be things like the vanishing camber problem. If I can get to where it almost always takes just a few minutes to hone I'll probably do it more often and become more sensitive to the loss of sharpness.

My second problem is not having a permanent sharpening station and having to get things out and put things back.

 

[matthewwh]

Consider how thick the steel is in the last 4-5 thousandths of an inch of the blade is. At 30 degrees the fifth of those thou is only going to be around 3 thou thick, so we are talking about a triangular piece of steel that at its thickest point would still fit within a dressmakers pin.

You have the blade cambered so the wear is not only localised in the middle portion of the blade but the tip of the camber is working harder than the bits either side of it. Without any honing you have run the blade along 68 feet of timber multiplied by however many passes you took at varying thicknesses of shaving to fully joint the edges. After that the blade has still taken finish shavings on another 48 feet of edges.

Considering this is a blade that was designed with edge taking ability as the top priority, I think you have effectively demonstrated just how impressive the wear resistance of properly forged and hardened O1 really is.

To summarise:

At the same hardness.

Carbon steels like O1 take the finest edge but need reasonably frequent honing to keep them working to their maximum potential. As you have demonstrated they will go on cutting for a lot longer than that if you let them. Despite the small difference in wear resistance from O1 to A2, carbon steel is easier to hone and feels much nicer on the stone.

Air hardening steels like A2 and D2 have better wear resistance at the price of some edge taking ability. They require a little more effort to sharpen and several A2 users from the forum recently agreed that they are probably best approached with diamond stones.

Moving on to your other points:

If you have watched David's excellent DVDs you will note that he mentions that planes do not automatically produce square edges from side to side (I think the phrase is "I don't have a built in spirit level" if that rings any bells) Anyhow, to achieve a truly square edge you have to work down to layout lines. This is a fundamental principle of planing so cambered or square blades will make little or no difference. Cambered irons are of great benefit when doing surfaces, so if that's the next job I'd reinstall your camber (in fact even if you took the middle straight across you probably still have enough of a curve left on the corners to avoid tramlines).

Bevel up or bevel down, effective pitches affect the way that the shaving breaks away from the timber beneath. by the time the shaving reaches the front edge of the cap iron, the moment has long passed.

In terms of what to do next, I believe that thinking through your sharpening setup is the top priority, if it's fast easy and enjoyable then you are much more likely to do it. Learning to spot the telltale signs of a blade that needs a few moments attention and sorting it out immediately will bring your times down considerably and vastly improve the results and enjoyment you get from your tools. After a while you will begin to take enormous pride in the fact that your tools are always properly maintained and ready to perform at the peak of their ability.

Your Clifton iron is an awesome piece of kit, with a little care it will put a glassy smooth surface on timber and yet can still cope with tough workmanlike jobs like the one that you just gave it without complaint.

All you need to do now is sharpen it up again and figure out what you are going to do with the remaining one thousand nine hundred and ninety five thou of its useable length.

 

[Handworkfan]

I was leaning towards getting a Veritas replacement blade (which costs half as much as the Clifton, at least here in the USA) and see if the problem recurs. (This blade would presumably have identical metallurgical properties to the blade in my other planes that have not exhibited this problem, so that would control for blade composition.)

Beware!
i can't speak for the metallurgy, but the adjustment systems are different and I'm quite sure a Veritas blade won't work in a Clifton plane.

 

[bugbear]

I was leaning towards getting a Veritas replacement blade (which costs half as much as the Clifton, at least here in the USA) and see if the problem recurs. (This blade would presumably have identical metallurgical properties to the blade in my other planes that have not exhibited this problem, so that would control for blade composition.)

Beware!
i can't speak for the metallurgy, but the adjustment systems are different and I'm quite sure a Veritas blade won't work in a Clifton plane.

Perhaps, with their shared bedrock heritage, a LN blade would fit.

I would tend towards the "check with Clifton and/or dealer" first though.

I have seen localised wear in a perfectly good blade, caused be a rather prolonged end grain shooting session in seasoned oak.

BugBear

 

[newt]

I hone my plane blades at the end of each working day.

 

[adrian]

I was leaning towards getting a Veritas replacement blade (which costs half as much as the Clifton, at least here in the USA) and see if the problem recurs. (This blade would presumably have identical metallurgical properties to the blade in my other planes that have not exhibited this problem, so that would control for blade composition.)

Beware!
i can't speak for the metallurgy, but the adjustment systems are different and I'm quite sure a Veritas blade won't work in a Clifton plane.

I was talking here about the Veritas blade that is sold as a replacement for a Stanley #7, not a blade meant for one of the Veritas planes. I had the impression that all of the Stanley #7 replacement blades would work and I'm aware of one from Veritas, the Hock, and the Ray Iles (D2).

 

[Handworkfan]

I was leaning towards getting a Veritas replacement blade (which costs half as much as the Clifton, at least here in the USA) and see if the problem recurs. (This blade would presumably have identical metallurgical properties to the blade in my other planes that have not exhibited this problem, so that would control for blade composition.)

Beware!
i can't speak for the metallurgy, but the adjustment systems are different and I'm quite sure a Veritas blade won't work in a Clifton plane.

I was talking here about the Veritas blade that is sold as a replacement for a Stanley #7, not a blade meant for one of the Veritas planes. I had the impression that all of the Stanley #7 replacement blades would work and I'm aware of one from Veritas, the Hock, and the Ray Iles (D2).

Ah, my apologies for teh confusion - that's something new I've elarnt, I didnt' realise LV did such a blade.
Good luck whatever you do.

 

[adrian]

Thanks very much to, matthewwh, for answering my questions.

I'm curious how much material you think could joint before needing to hone. Obviously you can't give a precise answer, since it depends on how many shavings I need to take and the wood and so on, but would you think I'd need to hone after ever 6 feet, say? I could, for example, decide to just start honing after every X feet even if I'm not aware of a loss of performance and maybe after doing that for a while I'd become better tuned to the performance of the tool. But what X would I choose?

If you have watched David's excellent DVDs you will note that he mentions that planes do not automatically produce square edges from side to side (I think the phrase is "I don't have a built in spirit level" if that rings any bells) Anyhow, to achieve a truly square edge you have to work down to layout lines. This is a fundamental principle of planing so cambered or square blades will make little or no difference. Cambered irons are of great benefit when doing surfaces, so if that's the next job I'd reinstall your camber (in fact even if you took the middle straight across you probably still have enough of a curve left on the corners to avoid tramlines).

Hmmm. I seem to have missed this fundamental principle somehow. I did all my surfacing without any layout lines and the first edge on each board I did also without any layout lines. The second edge of each board I marked a line but didn't worry too much about hitting it spot on since I didn't mind if the board edges were out of parallel by half a mm. I tried instead to make sure that the edges were flat and square using a square and straight edge.

1. How do you produce layout lines without having a reference surface that's flat to make them relative to? Don't you have to make one edge flat first before you can make a layout line relative to it?

2. Suppose I have my layout lines somehow. I still need to be able to remove wood from the right places. I find I'm much more successful at this with the cambered blade than with the straight blade. In other words, if I see that I need to remove more on the left and less on the right then I can, Charlesworth style, hold the plane to the left so that my cambered blade cuts more on the left. With a straight blade I guess I'm supposed to adjust the blade tilt to accomplish this. But I find adjusting the blade tilt accurately to be very difficult.

The next task is actually joinery. Carcasse dovetails. A groove. (The stopped groove seems to be kind of troublesome---I just found that the plough plane can't cut that.) And either dados or sliding dovetails for dividers. I haven't decided which. (I'm making a three drawer file cabinet.) The drawers can be seen here: http://members.cox.net/jsam/wood/drawers/drawers.html

After the joinery the final step is to surface and joint the curly maple for the drawer fronts, so surfacing may be the next task the bench planes will face. (You probably don't want to know how much lumber I surfaced without honing the blade in the Clifton. )

 

[Handworkfan]

If you have watched David's excellent DVDs you will note that he mentions that planes do not automatically produce square edges from side to side (I think the phrase is "I don't have a built in spirit level" if that rings any bells) Anyhow, to achieve a truly square edge you have to work down to layout lines.

It's unusual for me to take issue with matthew, so I've a feeling I might not be understanding this properly - are you saying that you'd mark layout lines before planing a face side and edge? Surely not - what would be the datum surfaces for such lines? A perfectly square edge can be planed without layout lines - but the lines are needed to get the opposite side or edge parallel.

 

[matthewwh]

Sorry if that was misleading, my intention was just to draw Adrian's attention to that part of the DVD.

Squaring a reference edge is one of the more difficult aspects of handplaning, and unless you have a fenced plane it can take some practice to get right.

The first step is to chop off any splits in the ends of the board and then flatten one face which will become your reference surface for the rest of the board. Planing across the grain with a cambered blade in a jack or fore plane first to remove any wind, cupping or bowing, then following with a try or jointer with the grain to achieve a flat surface.

The reference edge is then planed square to the reference face. This can be done by eye, with the help of a square and winding sticks to gauge the squareness of the edge. If you can see that the edge is not square you can tweak the lateral adjuster. If that doesn't fix it, check your stance and that the board is correctly held in the vice / bench slave. Alternatively you can lay a thin supporting board on the bench with the workpiece laid flat on top of it and shoot the edge using the plane on its side on the benchtop.

The reference face is then marked with a 'P' with the tail touching the reference edge, and a broad arrowhead on the edge pointing to the tail of the 'P'. All measurements are then taken with reference to one of these two surfaces.

The board is then marked for thickness all the way around using a marking gauge and the opposite face planed down to the marks. The width is marked in a similar way using a panel gauge on both faces and again simply planed down to the marks.

With this done, you can shoot an end square and cut the board to length, first marking your reference edge on the offcut if it is likely to be of a usable size.

 

[JohnCee]

D2 is like A2 on steroids, it has 11-13% Chromium (rocks) content so it takes an edge like a baby's backside and holds onto it forever. Great for things like survival knives where you can spend hours trying to get it reasonably sharp but may need to use it for weeks on end without the facility to resharpen it.

Matthew, I find that I can get a much better edge on my Ray Iles D2 irons than on my Lie Nielsen A2s. I also find the D2 irons quite easy to sharpen on waterstones, unlike the A2s. This seems to run counter to your expectation.... any thoughts???

 

[matthewwh]

Hi John,

A very good question. Unless you have received an O1 iron by mistake the only thing I can think of is that Ray may be heat treating it differently - leaving it slightly softer and relying on the high wear resistance to compensate. I wouldn't put it past him to quietly come up with some brilliant way of making it work, he is an exceptionally clever bloke.