For my other posts about woodworking tools, follow this link. And don't miss "Living Stones, Living Wood", the thrilling conclusion to "Potemkin the Woodworker", a four-part serial fiction inspired by these #AtoZchallenge posts.
Thousands of years ago, in the first centuries of the Copper Age, humanity learned to melt metals out of certain kinds of rock. Adding other kinds of metal to the melt changed the alloy composition and made the resulting tools harder and more durable, ushering in the Bronze Age. When societies advanced and gathered together the knowledge, skill, and centrally coordinated labor force necessary to identify other ores and dig it up in quantity, the Iron Age rose.
Blacksmithing and nascent metallurgy advanced hand in hand, producing better kinds of steel: alloys of iron with carbon, tin, copper, manganese, molybdenum, chromium. Today, there are dozens, hundreds of grades of common steel with various properties. Specialty steels number in the thousands. In this, the first years of the Golden Age of Materials Science, blades and other tools can be made of steel, ceramics, glass, carbon nanotubes and a host of other materials.
And throughout all of that history, in a thousand tongues, in a thousand places, in a thousand occupations, men and women have uttered the exact same sentiment, probably in the exact same sentence:
"Why is this damned tool so dull? I JUST sharpened it!"
I feel that pain, and I've said that very sentence. There's an old saying for this: the only way to keep your tools from getting dull is to never use them. Another fact is that while it's fun to use your tools, setting aside time to sharpen them is just work. There's some irony in that metal comes from stone, extracted from the ore by heat and pressure. However, to keep the metal useful (i.e. sharp), you have to bring it back in contact with stone.
There are various grades of whetstone, based on their level of abrasiveness. Some take off lots of metal, others are finer-grained and take off less. You need to match the stone to the degree of sharpening required, but also to the grade of steel, the angle (or compound cutting angles) you want to achieve, and to the type of cutting you are going to do.
Some blades are lubricated with water, some with light oil, some with heavy oil. The liquid serves to suspend the grains of stone in an abrasive slurry. That slurry does a lot of the work in removing microscopically thin flakes of metal from the tool's edge. The process of sharpening involves moving from one stone to another, then finishing with a honing strap.
Sharpening means removing metal and making a new cutting edge. Honing means unfolding the fine, fine lip of an existing cutting edge. On a micro level, the very thin lip (maybe a hundredth of a millimeter thick) can get bent over. Honing straightens it out. Frequent honing makes actual sharpening unnecessary, since the cutting edge never gets blunted and broken off.
A dull tool is a dangerous tool. Sharp tools bite exactly where you want them to go, while dull tools skip around on the workpiece, possibly marring the piece, possibly harming the woodworker.
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W is for Whetstone
Thousands of years ago, in the first centuries of the Copper Age, humanity learned to melt metals out of certain kinds of rock. Adding other kinds of metal to the melt changed the alloy composition and made the resulting tools harder and more durable, ushering in the Bronze Age. When societies advanced and gathered together the knowledge, skill, and centrally coordinated labor force necessary to identify other ores and dig it up in quantity, the Iron Age rose.
Blacksmithing and nascent metallurgy advanced hand in hand, producing better kinds of steel: alloys of iron with carbon, tin, copper, manganese, molybdenum, chromium. Today, there are dozens, hundreds of grades of common steel with various properties. Specialty steels number in the thousands. In this, the first years of the Golden Age of Materials Science, blades and other tools can be made of steel, ceramics, glass, carbon nanotubes and a host of other materials.
"Why is this damned tool so dull? I JUST sharpened it!"
I feel that pain, and I've said that very sentence. There's an old saying for this: the only way to keep your tools from getting dull is to never use them. Another fact is that while it's fun to use your tools, setting aside time to sharpen them is just work. There's some irony in that metal comes from stone, extracted from the ore by heat and pressure. However, to keep the metal useful (i.e. sharp), you have to bring it back in contact with stone.
There are various grades of whetstone, based on their level of abrasiveness. Some take off lots of metal, others are finer-grained and take off less. You need to match the stone to the degree of sharpening required, but also to the grade of steel, the angle (or compound cutting angles) you want to achieve, and to the type of cutting you are going to do.
Some blades are lubricated with water, some with light oil, some with heavy oil. The liquid serves to suspend the grains of stone in an abrasive slurry. That slurry does a lot of the work in removing microscopically thin flakes of metal from the tool's edge. The process of sharpening involves moving from one stone to another, then finishing with a honing strap.
Sharpening means removing metal and making a new cutting edge. Honing means unfolding the fine, fine lip of an existing cutting edge. On a micro level, the very thin lip (maybe a hundredth of a millimeter thick) can get bent over. Honing straightens it out. Frequent honing makes actual sharpening unnecessary, since the cutting edge never gets blunted and broken off.
A dull tool is a dangerous tool. Sharp tools bite exactly where you want them to go, while dull tools skip around on the workpiece, possibly marring the piece, possibly harming the woodworker.
............................
||| Comments are welcome |||
Help keep the words flowing.
I was taught to call that bent-over bit a "wire-edge," and that drawing the sharpened blade through the corner of a block of wood would remove it. I hate internalizing bad info. :-P
ReplyDeleteThis is why straight razors never wear out. Since they only cut human hair, they never hit anything that'll break off pieces from the edge. When they get dull, the honing unfolds that curve.
DeleteI think a wire edge is a bit different. When you sharpen a tool so as to change the cutting angle (in my case, almost ALWAYS unintentionally), the previous edge is only partially and intermittently attached. That run of metal should be removed, although I wouldn't use a block of wood for it. I'd use a leather strap or a couple of layers of denim.
I've used whetstones before, they're magic!
ReplyDeleteYou're messing with your own sort of world-building here!
ReplyDelete