Ruler trick, starting off the stone?

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Pulling the iron onto to the stone will fold the wire edge out... If you start with the iron on the stone with a push stroke, then the wire edge is folder under...


There is some debate about which method of managing the wire edge is actually better... But it gets kind of esoteric...


Important point of note: the whole 'David Charlesworth/Lie-Nielsen' workflow is not universally accepted as 'best practice'. The utility of the ruler trick is being hotly debated with many very experienced folks arguing that it's time has long since passed... In general, the utility of the ruler trick depends on what your honing (bevel-up, bevel-down) what steel is being honed (A2, D2, O1, etc) and what honing media your using (oil stone, clay-matrix waterstone, ceramic waterstone, etc)... It's been rather convincingly argued that the ruler trick should not be used on bevel-up irons or the softer steels.


The discussion is fairly esoteric and typically revolves around wear bevels, but you can delve into the rabbit hole yourself at Ron Hock's site:


As a second note: I was an early adopter of the ruler trick, but have now abandoned the practice. I still use the ruler trick for bevel-down irons in D2, M2, etc.


Good luck.

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I only use the ruler trick under two conditions:


1) the back side is too far gone to flatten propertly, or

2) when you actually wish to increase the blade's angle of attack in a bevel down configuration.


Most things in the sharpening realm are contested to some degree.   :)   But once you figure out how it all works you will see it is not all that complicated.



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==>new hock blade

If you're honing one of Ron's A2/cryos, using slow-speed honing media (oil-stones) or mid-speed honing media(clay-matrix waterstones) and it's a bevel-down iron, then yea, by all means, have at it -- use the ruler trick --- will help you a lot.


Don't get me wrong, I'm a fan of the Ruler Trick, it's simply that as I gained experience, I realize its benefits and pitfalls... When I switched to fast-cutting ceramic stones, the need for the Ruler Trick just dropped-off my Radar...


Unfortunately, folks sometimes take the Ruler Trick out of context and apply it when/where they shouldn't -- bevel-up irons, chisels, etc...


The Ruler Trick was adopted to address a particular set of problems at a particular point in time. A dozen or so years ago, the fastest honing media adopted by woodworkers were clay matrix-based synthetic Japanese waterstones. At the time, the introduction of harder steels into woodworking created a problem -- flattening the back of a plane iron went from being a pain in the ass to becoming a Royal pain in the ass. Very cleverly, a solution was the Ruler Trick... The minor back-bevel it introduced didn't hinder the performance of [most] bevel-down planes... In fact, it sometimes helped with difficult stock.


The problem is, solutions to a particular problem sometimes get applied where they shouldn't -- causing side-effects. Sort of like getting cut on your arm, the cut gets infected, taking an antibiotic, curing the infection --- but sh*tting your brains-out for a week because you also killed the helpful bacteria in your gut... Side Effects...


Further, with the lemming-like adoption of bevel-up planes (thanks to paid sponserships and the liberal application of soft marketing money), folks started using the Ruler Trick for bevel-up irons -- a place where its side-effects are more pronounced (i.e. the small back-bevel is not as benign on a bevel-up plane)... This is healthcare's Off-label Usage as applied to Woodworking... Sort of like developing a cardiac drug called Sildenafil that was efficacious in controlling hypertension (a narrow field of play that really doesn't generate much top-line growth)... But, in certain doses, Sildenafil did have an interesting side-effect with more up-side potential... Viagra  is one of the most profitable drugs in history... :)  Welcome to the world of BigPharma -- my home for the past decade or so...


As previously noted, the Ruler Trick has its place in the woodworker's bag of tricks... But we're also a decade farther down the road... Fast cutting ceramic stones are now common... For block plane irons in O1, you can just flatten the back faster than you can set-up the ruler... But for a #7 iron in A2, the Ruler Trick still has its place...

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What's the significance of starting a plane blade hanging partially off the stone when polishing the back using the ruler trick?

With regard to the Ruler Trick -- there really isn't an out-of-flat condition that abrasive sheets on glass won't handle in an hour or less for the most egregious offending cutters (hard steels too), much less for the 'average' out of flat unit.  Flatten your backs, throw ruler out.  Forget you ever read about it.  Flattening is a once-in-a-lifetime thing. 


Any new cutter you buy today, either as a replacement or as provided with a new plane (or a new chisel perhaps), simply should be flat and its back should immediately take a polish all the way to the cutting edge when honed in your shop.  If it isn't so, then send it back.  Don't let the manufacturer off the hook by falling for the Ruler Trick.


The Ruler Trick does not result in a sharper edge over a cutter with a flat and polished back that meets a well honed and polished bevel.  It was a workaround whose time has come and gone for vintage irons with bellied backs.  It was never really necessary for anybody who didn't mind using a little sandpaper on some sort of inexpensive but reasonably flat substrate.  Don't by the horse-pucky about having to use the Ruler Trick to get through the wear bevel.  Woodworkers have been honing past wear bevels for hundreds of years without it.  Hone frequently, work up a "scratchy" burr and work it off front to back and you will be past the wear and into freshly honed steel every time. 


Despite what you may read asserting the contrary, a back beveled iron in a bevel down plane is not and never will be a perfect substitute for a plane with a higher bedding angle when working difficult stock.  It's a little dodge to get you through a rough afternoon; it is not a long-term solution if you like to work in figured stock and other tough to plane species.

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