All about scrapers

[AHill]

A couple of points of order. I don't doubt for one minute his method works and works well. I haven't tried his way on a scraper. I'd be interested in hearing from anyone who has and whether scraper performance is any better than other more common methods. I don't see anything in his method that is fundamentally any different than other more popular methods, except for him "clearing the swarf" from under the burr.

Maybe I'm just not understanding exactly what he's saying, but he claims running the burnisher across the side surface when he removes the initial burr is work hardening the point of the scraper blade. All he's doing is deforming the burr, so when he turns the new burr, the steel that is moved isn't necessarily the same steel he work hardened by flattening the burr to the side of the scraper. All burrs are work hardened by definition, since you are deforming the metal to create a burr. You really wouldn't want to excessively harden the steel prior to creating a burr anyway, because that would mean the burr would be very brittle. Since burrs on scrapers are ultra thin to begin with, brittle would mean a fragile edge. Maybe what's happening is the first burr is too deformed to be useful. So he removes that burr by flattening it along the side, then turns another burr from a portion of the scraper that is already work hardened. Again, you get a harder burr, but risk it being too brittle and thus less durable.

Not a huge deal, but he claims a saw blade is "high carbon tool steel." No it's not. It's usually spring steel. Tool steel is generally defined as a alloy that is used to cut or machine other metals. Tool steels are usually high carbon, but many other alloying elements are added to enhance durability and wear. Most spring steels do not make for good cutting tools. You want a saw steel (and a scraper) to be low enough hardness to be able to sharpen using a file and flexible enough to have some resistance to cracking or permanently deforming in service. After all, in a saw, you're sharpening with a file and setting teeth, which means you need a moderate to low hardness, flexible steel. Lie Nielsen says they use Swedish spring steel in their saws. Swedish spring steel can mean a lot of different things. Most plain carbon spring steels, however, are high carbon steels.

[Timberwolf]

A couple of points of order.  I don't doubt for one minute his method works and works well.  I haven't tried his way on a scraper.  I'd be interested in hearing from anyone who has and whether scraper performance is any better than other more common methods.  I don't see anything in his method that is fundamentally any different than other more popular methods, except for him "clearing the swarf" from under the burr.

Maybe I'm just not understanding exactly what he's saying, but he claims running the burnisher across the side surface when he removes the initial burr is work hardening the point of the scraper blade.  All he's doing is deforming the burr, so when he turns the new burr, the steel that is moved isn't necessarily the same steel he work hardened by flattening the burr to the side of the scraper.  All burrs are work hardened by definition, since you are deforming the metal to create a burr.  You really wouldn't want to excessively harden the steel prior to creating a burr anyway, because that would mean the burr would be very brittle.  Since burrs on scrapers are ultra thin to begin with, brittle would mean a fragile edge.  Maybe what's happening is the first burr is too deformed to be useful.  So he removes that burr by flattening it along the side, then turns another burr from a portion of the scraper that is already work hardened.  Again, you get a harder burr, but risk it being too brittle and thus less durable.

Not a huge deal, but he claims a saw blade is "high carbon tool steel."  No it's not.  It's usually spring steel.  Tool steel is generally defined as a alloy that is used to cut or machine other metals.  Tool steels are usually high carbon, but many other alloying elements are added to enhance durability and wear.  Most spring steels do not make for good cutting tools.  You want a saw steel (and a scraper) to be low enough hardness to be able to sharpen using a file and flexible enough to have some resistance to cracking or permanently deforming in service.  After all, in a saw, you're sharpening with a file and setting teeth, which means you need a moderate to low hardness, flexible steel.  Lie Nielsen says they use Swedish spring steel in their saws.  Swedish spring steel can mean a lot of different things.  Most plain carbon spring steels, however, are high carbon steels.

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Lie Nielsen says they use Swedish spring steel in their saws.

Probably cashing in on the idea that Swedish steel was "more pure" than ordinary steel because they did not use fossil fuel in it's manufacture like other steel producers, and could be more accurately "tailored" to meet specific criteria..The ore was heated with electricity. One band saw blade maker today is proud to state that they use "Swedish silicon steel" in the manufacture of their blades. I have personally found that they don't retain their edge any longer than less expensive ones that I have used, yet cost twice as much...A lot of what is advertised is just "sales hype" IMO...I remember the fifties when the "best" cutlery was made with " German Solingen steel"..These days it is "surgical" steel...

[Tony Z]

I've used a variety of scrapers, both card and cabinet. The only thing consistent about them, is that everyone over thinks and over complicates preparing one.

[Handplanesandmore]

I've used a variety of scrapers, both card and cabinet.  The only thing consistent about them, is that everyone over thinks and over complicates preparing one.

Your statement is true not only for scrapers but also for sharpening in general. Some woodworkers are very good at sharpening as well as at complicating things, hence confusing or discouraging the newbies. In this respect, credits should be given to David Charlesworth for his ruler trick, and Rob Cosman for his simple two-stone regime. They helped make people realize that sharpening can be so simple, except those who view the sharpening process as the end rather than as a means.

Some people will sure fall for it, and chase after new sharpening media, new jigs, and new methods, even though their work won't get any better or different if they already master the basic technique. "New" is always thought to be better to them. Some magazines, of course, play a role in promoting some of the fads.

Simon

[Timberwolf]

Your statement is true not only for scrapers but also for sharpening in general. Some woodworkers are very good at sharpening as well as at complicating things, hence confusing or discouraging the newbies. In this respect, credits should be given to David Charlesworth for his ruler trick, and Rob Cosman for his simple two-stone regime. They helped make people realize that sharpening can be so simple, except those who view the sharpening process as the end rather than as a means.

Some people will sure fall for it, and chase after new sharpening media, new jigs, and new methods, even though their work won't get any better or different if they already master the basic technique. "New" is always thought to be better to them. Some magazines, of course, play a role in promoting some of the fads.

Simon

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Your statement is true not only for scrapers but also for sharpening in general.

Absolutely...lots of folks make it far more complicated than it really is....but I guess it sells magazines...

[Tony Z]

A super sharp Aldis chisel will trump a super dull LN chisel every time.