Bevel Up Plane Sharpening and Back Bevel Wear

[Erwin Graween]

Hi,

I have a question about the way to manage back bevel wear for Bevel Up planes. The question is not about bevel up vs bevel down (I'm not starting this kind of debate ;) ). My question is for bevel up users.

As of today I'm only honing the regular bevel and not using the ruler technique. That takes me time to hone correctly. I'm also only honing straight edges, not using any camber.
In short, I'm using my bevel plane (veritas low angle jack) mostly for shooting and edges.

I now want to start exploring also other uses (jakc, smoothing, ...). For that I'm wondering about the back bevel wear. So my questions are :

1- Are you using the ruler technique to produce a back bevel on your bevel up plane's blades ? Do you find it useful ?

2- When you have an camber, since (i.e: read Derck Cohen's article on his site) you must put more camber, then on bevel down plane. do you apply the ruler tecnique like you would on any plane or is there a particulare technique ? I'm thinking about the fact that the greater curve might introduce the need for a wide back bevel then on bevel down blades.

Thank you for your inputs.

Regards,
Erwin.

[Robert Engel]

I think a back bevel would only work on a standard bevel down plane, right? You're not changing the cutting geometry in a BU doing anything to the back.

Like you, I mainly use mine for endgrain and shooting, so I've never thought about cambering or easing the edges.

[ian maybury]

Hi Erwin. THis is just one not terribly expert view. I have several BU Lee Valley planes, but not what could be called long term experience with them. Most of what I do is filtered from what others have reported, and so far it seems to work just fine. I have a block set up with a little camber as a small smoother, the big/wide smoother also with a little camber, a jack which is sharpened straight for shooting board use, and a jointer with light camber with an eye to use on setting up edge joints. (not tested on that application yet)

I have Shapton waterstones down to 12,000, and after years of more informal hand sharpening on old planes used for carpentry now use a tweaked Veritas Mk 2 honing guide. I've been using a WorkSharp with the wide blade platform and the honing guide for light grinding.

Derek Cohen's site is the biggest and best single resource i've seen for BU reviews and for reliable sharpening techniques. David Charlesworth's books for the fundamentals of waterstone sharpening in general. What i'm doing is close but doesn't necessarily replicate precisely what the guys do, but the key princples seem to click. (David would probably beg to differ on use of the ruler vs what i say below for example)

Be that as it may:

(1) The ruler technique may not be such a great idea (but it's definitely do-able) on a low angle BU because it reduces the just adequate clearance angle over the work surface and could (?) influence the feel of the tool and the rate of wear of the edge if reduced further. (it's not directly relevant, but metal cutting experience suggests that adequate clearance is important) My experience has been that the backs of the several (5 so far) LV irons are so accurately flat that they reliably clean up all over on a 1,000 grit waterstone in a few minutes - so to my mind there's not so much incentive to try it.

(2) Derek's suggestion to always use 25 deg irons and to then adjust the cutting angle using a microbevel seems to work well. It avoids the issue of needing to hone away large volumes of metal when adding a microbevel or camber on a thick iron - the low angle needs more than a more steeply bedded iron too.

(3) I'm not running heavy camber on anything ( i have a scrub, but use machines for most of the stock preparation i've done - so there's not so far been a big need to shift huge amounts of material), but it's easy to add camber as required with extra strokes on the 1,000 grit on the main bevel only to each side - say 10 extra to the corners, 5 at 1/4 and 3/4 or multiples of. (the technique David Charlesworth published)

First time through was harder work since I had bought some irons with steeper bevels than 25 deg and ended up grinding them back to 25 deg by various means (needs a lot of care to avoid heat damage), and there was some dialling in of the honing guide and figuring out of the details of technique. That said it's proven no problem to deliver and maintain edges which for me were a revelation - the smoothers went under 0.001in shavings on straight grained wood instantly, feel great and deliver a beautiful finish. (and believe me i'm picky)

:) I'll get in trouble in some quarters for saying this (and for sure the ruler has it uses in certain circumstances), but i'd so far prefer to do a little extra work on the bevel side to ensure that the wear bevels are fully cut away than get into using rulers and the like to create a back bevel. The topic was the subject of very heavy discussion recently, and there is probably some theoretical labour and metal saving (and this isn't to say it can't be done or that it might not be a good move in the case of a less flat back) - but as you point up i too would need to figure out how to handle it in a situation where there was significant camber….

[Jim Koepke]

Howdy Erwin,

My blades usually only get their back to the stones to remove a burr made when honing the bevel.

As with so many things, people have their own ways of accomplishing the same end.

Here is something of mine from a few years ago about blade cambering:

http://www.sawmillcreek.org/showthread.php?158373-My-Camber-Blade-Round-Tuit-Finally-Came

The same technique works for bevel up or down.

One thing to consider with any kind of back bevel is there will be a lot of metal to remove if it turns out not to work as well as was wanted.

jtk

[lowell holmes]

I'm not one to analyze and theorize even a bit about such things, but I can tell you I use the ruler trick on all of my planes, both bu and bevel down planes.

I started using the trick at Robin Lee's suggestion when I commented my LV apron plane wouldn't perform like his. He posted that If I used the ruler trick it would help and it did.:)

Cambering the bu irons is another issue. I follow someone's suggestion and that is to slightly radius the corners of the iron. I never had much cambering a bevel up iron, but here are members of this group that do.

[Pat Barry]

My take is, yes, give it the ruler trick. This helps assure a sharp cutting edge with less bevel grinding / honing. Don't overdo i though - its just a tweak

[Reinis Kanders]

Ruler trick makes it harder to chase the burr though, so I only use it if blade is messed up by pitting or what not.

[lowell holmes]

Thirty strokes on a strop will eliminate the burr. I use green compound on a slab of mdf. I follow Paul Sellers method of thirty fast strokes and it leaves a very sharp edge.

[Derek Cohen]

Wear on a plane blade occurs on both sides. However, the act of rubbing a plane blade along a wooden surface does cause the steel to wear more in that area. In a BD plane, the act of honing the bevel removes this extra wear. In a BU blade, the wear is on the reverse side of the bevel, and is referred to as a "wear bevel".

Both BD and BU planes require attention to both sides of the bevel - one without the other simply leaves a serrated edge on the remaining side. Honing or grinding the bevel does it simply with the BD blade. There are essentially two methods of dealing with the wear bevel on a BU plane.

1. The first is to hone or strop the back of the blade frequently. How frequently depends on the type of steel (how abrasion-resistant it is) and the abrasiveness of the wood. Softer woods such as Pine are going to be very different compared to harder, silica-containing woods such a Jarrah. A2 is going to outlast O1, and in turn be outlasted by PM-V11.

2. When honing, do the "Ruler Trick". This places a micro secondary bevel (of about 2/3 degree) at the very spot where a wear bevel would encroach. This amount is not going to reduce the clearance angle (the bed is 12 degrees and anything past 7 degrees is pretty safe).

The downside of the Ruler Trick is that it is harder to maintain an edge by stropping. You certainly can just pull the blade along a leather strop in the usual way, and the "give" in the leather will likely be enough to hone the micro secondary already there. What I would rather do, to be sure that this area is being honed, is to "strop" on a fine stone repeating the Ruler Trick. It takes the same time as stropping but is precise.

What I have found over the years is that refreshing the (flat) back of the blade is usually enough to keep a plane going longer. This is the case for both BU and BD planes. It is just a lot easier to do this on BD plane blades since the BU blades typically have a high micro secondary bevel on a low primary bevel if cambered. Keeping this angle fairly accurate is more important on a BU plane than on a BD plane.

Regards from Perth

Derek

[Mark Almeidus]

I am not an expert into this to much, but recently i was watching rob cosmans sharpening technique.
https://www.youtube.com/watch?v=ZbInhTxtRcw
He is doing 3 microbevels on the bevel side and one microbevel on the back. I find it overkill with 3 microbevels and can be complicated, but i tried one microbevel on the front at about 4 or 5 degrees, and one on the back with a ruler just to remove the bur completely. I never achieved that sharp blades before. I am using sandpapers, (highest been 1200 girt). I dont see reason why not this work for a bevel down planes. Or you can try just with a microbevel on the bevel side handheld, about 10 15 strokes will be enough with light presure.

[Jim Matthews]

Fine Woodworking published an article addressing this method.

http://www.finewoodworking.com/tool-guide/article/one-bench-plane-can-do-it-all.aspx

[ian maybury]

Guess that's Erwin well and truly confused! It seems clearly as Jim that there's different ways to accomplish the required end.

To Derek.. I've been operating on the basis that while yes, there is a wear bevel on both sides on a BU (on a BD too) that (admittedly a little extra) honing on the bevel side to cut back through them eliminates both. What may not have been clear from the post is that while i haven't so far discovered any need to use a back bevel/ruler, i have as you say been 'refreshing' the back on the flat as well every time. i.e. on the basis that it's necessary to work both sides to create a clean/sharp edge.

Time will tell on this - it's clear for example that if even the slightest dubbing of the flat back caused either by a slightly out of flat stone, rippling in the sharpening film or touching the iron down edge first occurs that it may be time to head for the ruler - or get into a major re-flattening exercise since the resulting dub/accidental back bevel may extend some distance back up the iron. It's hard to over emphasise just how critical stone and hence back flatness are in this situation.

I'm not for one moment arguing the ruler doesn't work, just that my personal instinct has been to if possible avoid the added complexity. Less the first time through, more after repeated re-sharpenings. Especially when using cambers - a straight edge with relieved corners would simplify the deal. I guess what threw me a bit was the discovery of how few strokes it takes on a waterstone to create a micro bevel, and as a result how easy it is to overdo any back bevel….

[Robert Engel]

Ian I'm with you on the back bevel thing.
I still can't get my mind around why you would even do it on a BU - increase blade life? How can it affect the performance?
Bottom line I've tried it don't see an advantage for me.
I've always thought its for that little "extra" for sharpening I don't see how 1 or 2 degrees is going to provide any kind of "relief angle" effect.
If we're doing it to get around flattening the back, then I think its a mistake in the long run.
But it sure is popular so I must be missing something.

[Brian Holcombe]

Ruler trick makes it harder to chase the burr though, so I only use it if blade is messed up by pitting or what not.

Here is my recent experience and a disclaimer;

I generally avoid the ruler trick, I'd rather have a flat back on the blade.

My jointer has such a wide blade that it is a bit aggravating to work the back of the blade, so in using the ruler trick I'm bringing that huge area down to just the point that matters. I keep the same ruler handy and use it when tuning that blade. It turns a marathon into a dash.

Between full resharpenings I'll go back to the natural finish stone and strop a few times and once the edge really needs a makeover I go back to 1000 grit.

It does effect how I strop the back of the blade, as I have to raise the back of the blade ever so slightly to catch the wire edge and remove it.

[ian maybury]

As i see it the primary usefulness of the ruler trick (as Brian and others above) is when it's difficult to precisely flatten the back/'flat' side of either a BU or BD iron. (e.g. a slightly roughly ground iron can require an enormous amount of work to sort it out - the very precise flatness of the LV items seems to result from their being factory lapped)

The difficulty that arises in that case is that it becomes impossible (without this large amount of flattening work) to finish the 'flat' side right up to the cutting edge - because the full length of the area behind the cutting edge is not fully in contact with the stone.

I think it is easily possible (using a slightly steeper micro-bevel) to cut back the primary bevel enough so that as in the post above the wear bevels are eliminated from both sides, but if it's not cut back enough then some wear bevel may be left behind on the flat side that will cause an improperly formed edge (our two precisely formed facets meeting at an angle), and a problem similar to above. The difficulty though is that even if it is cut back enough to obliterate the wear bevels on both sides the less than perfect contact of a less than precisely flat 'flat' side with the stone will make it difficult to completely remove the wire edge by working the back flat on the stone.

Linking the usefulness of the ruler ttrick to less than microscopiscally flat backed irons may be controversial - it's got to be hard for a proponent of the ruler trick that represents an iron maker to be direct on it. Its got to be very useful in the case of both BD or BU irons though - it as others permits the finishing of a narrow strip of the flat behind/right up to the cutting edge without the need to very precisely polish the entire back flat. The tiny angle of the back bevel it puts on is not regarded as being enough to influence the performance of either type of plane plane.

The other scenario where it should prove very useful is when we don't manage for whatever reason to maintain a precisely flat back on our irons - and this seems likely to be the norm for a lot of us. As above even one episode of polishing the back of an iron while forgetting to flatten the stone in time (or an instance of even a small problem in our back flattening - maybe only due to something like wear in a plate) may dub the back of the iron enough to make the ruler trick a very useful alternative to a major flattening exercise. It's very easy to get caught this way - one of the classic 'i've honed it but it's still not cutting right' scenarios.

This could be one of the key benefits of stropping too - as a method it's not flatness sensitive.

My insinct is to shoot for flatness and precision, as my training is to feel that there has to be a catch (especially in terms of cumulative effects over time) to quicker methods. The day may well come when i'll be happy to use them though..

Pardon the length, but this isn't the same scenario as putting a significant micro bevel/back bevel on the flat/forward side of a trad BD plane iron to alter the cutting angle to deliver definite and very useful effects, or putting a steeper micro bevel on the bevel side of a BU plane for the same or similar reason. In both of these cases the cutting angle is significantly altered - which can be very useful to e.g. help reduce tear out. The matter of cap iron position kicks in in the case of a BD plane too - separating the effect of this and the cutting angle isn't easy/leads to lots of debate and is the subject of ongoing work by some here and elsewhere...

[ian maybury]

Just a PS thought on the self raised question of how to handle putting a back bevel on/to ruler trick a cambered iron.

I've never tried it, but a self adhesive abrasion resistant plastic (cut from self adhesive UHMW tape?) or maybe metal spot/disc of maybe 3/8in dia of appropriate thickness placed at the correct distance back from the cutting edge and on the centreline of the iron might be the plan. It'd permit rocking the blade to follow the camber as does a narrow or cambered honing guide roller when forming the camber in the first place.

It'd also be an option for doing straight edged irons, would permit working the waterstone lengthwise (instead of crosswise), and would deliver a flat bevel/avoid the issue of creating a convex back bevel as can happen on a rule if the iron is drawn back too far on it.

Either way it'd need care to avoid pulling the iron back so far that it fell off the edge of the stone, but it wouldn't do any harm as such. It'd be a good idea to wash the appropriate area on the iron first with some solvent on a tissue to degrease it......

[Reinis Kanders]

Seems like a lot of fuss.

Reminds me about Scythe sharpening. I just bought out of curiousity an old stone from eBay that was specifically for scythe sharpening. So I googled around about scythe stones and there were some sites with complicated procedures and water filled holders for the stone, etc. On the other hand I spent my summers on my grandparents farm and they scythed all their grass for hay. Enough for 3 cows and 10 sheep or so, so quite a bit of hay. I helped to scythe from relatively early age, all boys did. Sharpening was no big deel, basic stone, some swipes with it and back to work, peening was more complicated, but we boys kind of winged it.


Just a PS thought on the self raised question of how to handle putting a back bevel on/to ruler trick a cambered iron.

I've never tried it, but a self adhesive abrasion resistant plastic (cut from self adhesive UHMW tape?) or maybe metal spot/disc of maybe 3/8in dia of appropriate thickness placed at the correct distance back from the cutting edge and on the centreline of the iron might be the plan. It'd permit rocking the blade to follow the camber as does a narrow or cambered honing guide roller when forming the camber in the first place.

It'd also be an option for doing straight edged irons, would permit working the waterstone lengthwise (instead of crosswise), and would deliver a flat bevel/avoid the issue of creating a convex back bevel as can happen on a rule if the iron is drawn back too far on it.

Either way it'd need care to avoid pulling the iron back so far that it fell off the edge of the stone, but it wouldn't do any harm as such. It'd be a good idea to wash the appropriate area on the iron first with some solvent on a tissue to degrease it......

[John Schtrumpf]

I have 5 bevel up planes, I religiously put 2 to 4 light strokes on my 8k stone with the ruler trick when I sharpen them. I don't know if it makes a difference, that's why I said religiously :)

My small bevel up smoother has a very very slight camber, and I treat no different than the others.

If I were to have a bevel up plane with a large camber, it would be for heavy work. So I would do the same 2 to 4 light strokes with the ruler trick, just hitting the center of the blade and not worry about the rest.

[ian maybury]

Guess it depends on your preferred approach Reinis. A minor amount of camber (maybe only a few thou) may not to cause bother, but even so a cambered iron on a full width support can only touch down along the full length of the cutting edge as a result of it's tipping a little on the rule, or something similary indeterminate happening.

Maybe I should have used John's word - religion - instead of 'approach'. I guess we try stuff acording to our instincts, and when we get something to work in our specific situation we adopt it. :) The trick is perhaps to avoid getting religious about it....

[James Pallas]

I may be missing something here and need to be enlightened. If you use the ruler trick, each time you do so the back bevel gets longer unless you take a greater amount off of the bevel to equal out. Why would you not just take the bevel back what you need and leave it at that. If the back bevel gets long you have to grind back to it anyway or do a huge amount to re flatten the back.
Jim

[david charlesworth]

James,

Anyone who uses the ruler trick succesfully will confirm that the minute 2/3 degree back bevel does not get longer than about 2 mm.

Steel is removed from the secondary bevel with a coarse stone, i.e. relatively quickly when forming a wire edge.

The ruler trick bevel is done on a polishing stone such as 8,000 grit, so very little metal is removed.

David Charlesworth

[Derek Cohen]

I will add something to David's comment. My method for the Ruler Trick differs from his own (apparently Rob Cosman does it the same way as I do) ...

Where David demonstrates the RT with front-and-back movement, I prefer a side-to-side movement. The difference is that the former creates a longer, gentle arc, while the latter creates a shorter micro bevel. I imagine that the latter is easier to remove when honing the secondary bevel - David .. yes/no?

Regards from Perth

Derek

[george wilson]

About the 30 swipes: I do not see how anyone can give a definite number of strokes that are required to strop an edge. As for the ruler trick on BU planes,it is possible to get the cutting angle of the iron so low that the blade will just NOT cut. So,be careful. I have had that happen. Putting a bevel on the underside of BU irons does lower the cutting angle of the blade.

[Pat Barry]

About the 30 swipes: I do not see how anyone can give a definite number of strokes that are required to strop an edge. As for the ruler trick on BU planes,it is possible to get the cutting angle of the iron so low that the blade will just NOT cut. So,be careful. I have had that happen. Putting a bevel on the underside of BU irons does lower the cutting angle of the blade.
I don't see how the ruler trick can result in a reduction of the cutting angle on a BU plane. The cutting angle is defined by the entry side (BU) of the blade and the back bevel is on the opposite side. How can it lower the cutting angle? It does reduce the material at the cutting edge slightly but shouldn't be done so much as to really be noticeable. Now, on a BD plane the back bevel actually directly effects (increases) the cutting angle

[James Pallas]

Thanks for all of the replies to my question. I think I have a handle on it now. I agree with George on the changing of the angle at the cutting edge. By adding the very slight bevel it does make the cutting edge ever so slightly less acute. I think for my use I will stay with the flat. I have five BU planes jointer, Jack, smoother, rabbet Jack, and block. Plus some Stanley blocks. I also have all of the blades for the Veritas planes. Because of back issues I can't push a plane anymore to take big shavings. I kind of look at it as having different length smoothers. I think with heavy use I may take the ruler as a quicker method to get back to work. I think I accomplished what I wanted to by buying the BU planes. I think Derek has it pinned down with his center of force theory. I have to have the bench or the work high and get behind the plane in order to work. It does get more difficult with the high angle blades but with light cuts it is doable. Thanks again for the replies.
Jim

[ian maybury]

Seems to me that all these perspectives make sense. It's clear that the ruler trick must only (judging by how little it takes to put on a camber or a micro bevel) require the tiniest of touches (a few light strokes on a very fine stone as David) to fulfil its function of cleaning up the back face of the iron/removing any wear bevel or wire edge right at the cutting edge - and that it's very easily overdone.

The result (even though it's a very short bevel) has to be some slight reduction in clearance angle to the back/underside of a BU blade. It's clear too that low angle BU planes are not endowed with a surplus of clearance in this area, and that it may have some minimal effect - but against that it's clearly not a show stopper since it's successfully used by many on BU blades, and recommended by some makers. My personal instinct is to avoid it for this reason on a BU. For sure overdoing it especially on a BU iron seems likely to have the potential to cause bother.

Against that getting an edge to clean up reliably with a flat back requires a really flat stone - and a very carefully flattened iron too. Even the tiniest slip in respect of either has the potential to cause problems in that it may result in the area behing the edge not quite properly touching down (Maybe ony microns short) on the surface of the stone when polishing/finishing the back to remove the wear bevel/wire edge.

This is just a personal observation, but for example i've tried using a permanent felt marker to 'blue' back of an iron when polishing it and found that the stone will sometimes wipe the marker off a small area before the surface of the iron shows clearly that it's being polished. There's potentially all sorts going on under the iron what with slurry and the like to confuse the issue, but it may suggest for example that ultimately a very carefully flattened waterstone is delivering a surface flat to within less than the thickness of the ink film - and that this is likely necessary if the aim is to get the edge to clean up reliably using a flat back.

If this is remotely true it's possible to see why many swear by (a) the ruler trick, and (b) techniques like stropping that remove some of this pretty extreme dependency on achieving flatness/precision every time.

Bottom line as in everything else it's about skill and finding a technique that works. We can talk till the cows come home, but in the end we have to create a reality that works. Heaven knows what's actually going on at the detail level in these situations, so to some level we're all reduced to John's 'religion'. As in it worked this way the last time, so let's do it again. It mightn't be the only way through the maze though, so if one doesn't work then try the other........

[george wilson]

Give it some thought,Pat. It does lower the cutting angle that is presented to the wood on the underside of the iron. Not complicated.

[Stewie Simpson]

About the 30 swipes: I do not see how anyone can give a definite number of strokes that are required to strop an edge. As for the ruler trick on BU planes,it is possible to get the cutting angle of the iron so low that the blade will just NOT cut. So,be careful. I have had that happen. Putting a bevel on the underside of BU irons does lower the cutting angle of the blade.

I would concur with Georges comment. Its not overly difficult to end up with no clearance angle on a 12 degree bed.

As for this latest idea of the Schwarz to add a burred edge to the cap iron to improve its contact with the plane iron, LN and LV should take note that their move away from the traditional shaped sprung cap iron is a poor innovation.

[Pat Barry]

I would concur with Georges comment. Its not overly difficult to end up with no clearance angle on a 12 degree bed.
OK, so you agree with George but you are talking clearance angle and he is saying cutting angle, and I just don't see those as being the same thing. I do see a reduced clearance, but not a reduced cutting angle - the cutting angle is determined by the bevel angle. The back bevel fro the ruler trick does affect the clearance, theoretically, but this is a very small amount. Done.

[david charlesworth]

The ruler trick bevel is 2/3rds of one degree. This makes an insignificantly small change to the clearance angle, and it does not change with time.

Derek,

I can't see why the different direction of stroke should make much difference to width of RT polish. Both keep edge no more than 1/4 inch on to stone.

The reason I prefer crosswise is that lengthwise is an invitation for the unwary to produce a convex surface, (in the width).

Point pressure in the center is more likely to produce flat.

By the way, Rob has a new you tube video about preparing a Woodriver 5 1/2 which I think is rather good, except for the length ways perversion ~;-)#

However he and Derek would probably not count as unwary!

best wishes,
David

[Derek Cohen]

The ruler trick bevel is 2/3rds of one degree. This makes an insignificantly small change to the clearance angle, and it does not change with time.

Derek,

I can't see why the different direction of stroke should make much difference to width of RT polish. Both keep edge no more than 1/4 inch on to stone.

The reason I prefer crosswise is that lengthwise is an invitation for the unwary to produce a convex surface, (in the width).

Point pressure in the center is more likely to produce flat.

By the way, Rob has a new you tube video about preparing a Woodriver 5 1/2 which I think is rather good, except for the length ways perversion ~;-)#

However he and Derek would probably not count as unwary!

best wishes,
David


Hi David

I have not given thought till now that there may be two "methods" of the RT, and if one is "better". I suspect that the procedure I use creates a smaller back bevel, and that this is easier to remove, if one so chooses. It is equally interesting that there may be two options to follow. I have not put them side by side, and so I am just curious whether there are differences. Perhaps you can comment. Other voices are invited as well.

What is the difference? Well in your original method you demonstrated moving the back of the bevel over the edge of the stone, drawing it back about 1/4"-3/8", and then repeating this movement. This should create a tapered back bevel in width. In the method I use, the blade is moved in a side-to-side movement. I attempt to keep a straight, unwavering line just inside the edge of the stone. This creates a narrower back bevel.

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Ruler-Trick_zpsd6p8srcl.jpg

Here is a picture of Deneb (at LN) in the forward position ...

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/RT2_zpsyz8gan5u.jpg

... and the rear position ..

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/RT-back_zpsogutk8g6.jpg

There is a Youtube video here (look at the 2:30 minute mark): https://www.youtube.com/watch?v=VOvqbrdNZBU

Regards from Perth

Derek

[ian maybury]

Whatever about the differences, a quick look at 5.40 on this Rob Cosman video shows precisely why the ruler trick is at times so useful: https://www.youtube.com/watch?v=MYM08CSopNA

[david charlesworth]

Derek,

I do like your pictures, very clear!

Originally I preferred crosswise for three reasons.

1. I felt it made preserving flatness of width easier.

2. I prefer to have my stone scratches at rightangles to the edge.

3. There would be no tendency to dig a groove into the length of the (soft) stone.

Deneb has changed to the lengthways perversion but cannot remember the reason.

Harrelson is a man who prefers lateral scratches but I can't imagine why.

I will continue to practice my original method as it works very well for me.

There has never been a reason to remove the ruler trick polish on a blade so I have no idea if it would take long! Can't understand why this question comes up so much.

best wishes,
David

[Steve Voigt]

Whatever about the differences, a quick look at 5.40 on this Rob Cosman video shows precisely why the ruler trick is at times so useful: https://www.youtube.com/watch?v=MYM08CSopNA

OK, I took the bait and watched the video. I have no idea how this shows that the ruler trick is useful. What I notice is that Cosman spends more time polishing the back with his ruler trick than anyone would need to with a flat back, right on the stone. The only difference I can see is that you have to find your ruler, lay it in position, be careful not to disturb it while you're flattening, and then clean the ruler off when you're done. A small annoyance, but an annoyance nonetheless, every.single.time.you.sharpen, for the rest of your life. No thanks.

[david charlesworth]

Steve,

I have not seen the video, but your first point demonstrates thet you have completely missed the point.

If there is wear to be removed, and a wire edge, it will be significantly quicker and more reliable with the ruler trick.

However I have no expectation that you will agree.........

David Charlesworth

[Graham Haydon]

Although this is now veering away from the op as I rarely use a BU plane. However I've actually started to try the method David Charlesworth has shown on some shapton ha-no-kuromaku #5000 & #12000. It's led me to think that there is no real time to be saved with any particular method. If and when David Weaver (well worth checking out his channel https://www.youtube.com/user/daw162) does a video on plane sharpening I suspect it'll be very quick but for now most methods I've tried or seen take similar amounts of time which is not very long at all. What can be said is the method David Charlesworth shows works very well and it'll be no surprise the resultant edges are superb.

[Pat Barry]

Yeah, that 3 second procedure each.and.every.time.you.sharpen has to be really annoying. LOL. Actually, I'm impressed that some people get so good at the whole process they don't need tricks. Must be the difference between them pro's and us amateurs. I keep forgetting that we aren't all the same level of expertise here. There are many ways to skin this cat after all.

[Steve Voigt]

David,

I was responding to the claim that the video shows why the ruler trick is useful. If you haven't watched the video, I don't see how you are in a position to pass judgement.




If there is wear to be removed, and a wire edge, it will be significantly quicker and more reliable with the ruler trick.



I'll repeat what I said before: In the video, he works the back longer than is necessary without the ruler trick (given a properly flattened back). So how is it "significantly quicker?" If you want to come back and tell me that he is working the back a lot longer than you would, then that's a better argument. But I have a feeling he's not…

[Alan Schwabacher]

I'll repeat what I said before: In the video, he works the back longer than is necessary without the ruler trick (given a properly flattened back). So how is it "significantly quicker?"

He has just flattened the back on a 1000 grit stone, and then using the ruler trick, he spends 10 seconds on the back with a 16000 grit stone. Are you saying you need less than 10 seconds to flatten the entire back of a plane iron when making a grit step of that size?

Or are you referring to an earlier part of the video I didn't watch where he does stuff having nothing to do with the ruler trick?

[Steve Voigt]

He has just flattened the back on a 1000 grit stone, and then using the ruler trick, he spends 10 seconds on the back with a 16000 grit stone. Are you saying you need less than 10 seconds to flatten the entire back of a plane iron when making a grit step of that size?

Or are you referring to an earlier part of the video I didn't watch where he does stuff having nothing to do with the ruler trick?

Why would you flatten the entire back? I would do the last 1 1/2 - 2 inches. A lot of people would do considerably less than that.
You're right though; I missed that he is coming from a 1000 stone. So no, I would not spend less time--in fact I would spend more--on the initial flattening. But that doesn't affect the essential point, which is that it takes but a few seconds on a flat back to knock off the wear and the wire edge, so where is the great time savings?

[John Schtrumpf]

Just to add, the back of my Wood River blade was not flat when I got it new. Also if you listen to Rob Cosman, he is doing the initial flattening on a new blade (and plane).

Edit: Sorry Steve I must have missed your last post, but I will leave mine anyway.

[ian maybury]

Sorry guys, i didn't mean to be vague either. I was trying to keep it focused on the fundamental of why one or other method might make the best sense or at least be a realistic option in a given situation. Not to argue that one or other one size fits all option is always the best. What i meant to point out in the video was simply that judging by the area it shows as having been worked using the ruler trick and it's shape the WR iron was at first sharpening (not the same as subsequent sharpenings) quite a bit out of flat. (there's a very clear view showing that a large area had been worked using the ruler at the time listed) Against that it also demonstrated very nicely that the ruler trick is a quick and effective way to get over this issue - if it's present. Full marks to Rob C for showing it for real.

What i was trying say in perhaps a somewhat indirect way is that if you get a very flat iron then there's clearly less incentive to think in terms of using ther ruler trick. So far all i've had is about five from Lee Valley, and one from Clifton - and all six cleaned up in a few minutes without a ruler on a 1,000 grit Shapton. The Clifton took a bit more, but was still good. Every other example of those brands in the world could be very different for all i know...

There may be other scenarios i'm missing, but the second issue which i've been pointing to as well is that it's also very easy to start with a very flat iron - and as a result of either trying to flatten it on a less than perfectly flat waterstone (and even with the best will in the world its easy to accidentally do this - David has been a pioneer in setting out well thought through ways to avoid this problem), or of mishandling it on the stone (e.g. applying uneven pressure) it's very easy to end up dubbing the back of the iron enough to matter. Bearing in mind that a few microns are literally the difference between polishing right up to the cutting edge and properly removing any wire edge when working a flat back - and not.

There's two basic options open to us. The first is to be very picky and precise indeed about how we handle the flattening of our waterstones and how we work our irons on them - much more picky than i suspect that many of us are. The alternative is to head for the ruler, or else maybe to finish off our sharpening with a reasonably heavy stropping - both techniques that don't require quite the same level of geometric precision.

I guess the point is that in the big picture there's going to be a technique that works best for each of us - given our preferences, methods and how we apply them. There's as before an argument for not using the ruler on a bevel up, but as before it's not a show stopper. Against that i'd not want to ruler trick a BU quite a heavily as in the video, and as before preferably not at all if it's avoidable. The plane there though is a BD, and consequently it's not an issue there.

Guess what i'm trying to communicate is the view that these are all techniques that can be used when the occasion demands, and as suits - although the ruler trick is potentially a much less demanding way of getting a plane working well in a short time, and at times/with a less than perfectly flat iron and stone (short of spending huge amounts of time back flattening - and what do you do if e.g. your diamond plate is less than perfectly flat) may be the only practical route. Tools in our mental toolbox so to speak...

[Pedro Reyes]

OK, I took the bait and watched the video. I have no idea how this shows that the ruler trick is useful. What I notice is that Cosman spends more time polishing the back with his ruler trick than anyone would need to with a flat back, right on the stone. The only difference I can see is that you have to find your ruler, lay it in position, be careful not to disturb it while you're flattening, and then clean the ruler off when you're done. A small annoyance, but an annoyance nonetheless, every.single.time.you.sharpen, for the rest of your life. No thanks.


Disclaimer 1: I have not watched that video
Disclaimer 2: I don't use the ruler trick
Disclaimer 3: You are not allowed to ask me why I don't use it ;-)

... But I have 2 of David's books, and I believe I read about it there years ago, and I think it is useful.

In a perfect world, our stones are perfectly flat up to the very edges, and in a perfect world we can hold our blades perfectly parallel to that stone, and even move the blade back and forth, so that both perfect planes meet and a wire edge is removed with little work.

Using the ruler trick eliminates the need for all those "perfectly" conditions. I would lie if I said that my blades never tip up from having about 80% of the blade unsupported on the stone, I assume it has happened to all of us, I think the ruler trick helps minimize this, it virtually guarantees that you are always working that wire edge.

Pedro