*****************
Sharpening FAQ
Knifeman
The subject of the following article is on -Sharpening- ( with both
improvised and & modern sharpening media ) .
*************Sharpening***************
When I was a in my late teens, I discovered my Grandfather's sharpening
stone. I had some scrap steel rectangles laying around the house, so I
decided to see if I could sharpen these blunt pieces of steel into usable
tools. I soon discovered sharpening was a skill. I spent hours trying
different ways to speed up what I was trying to accomplish. The following
article is what I learned that day and the lessons of years of sharpening
knives both professionally as well as in the woods and streets in desperate
need of a sharp tool. The first thing you need to understand about making
something "sharp", are angles. A wedge is man's oldest tool.(Notice how I
didn't say a knife?) The wedge is what can enter through a small slit and
leave removing a sliver to halve the intended material. When we think about
it just about any shape contains wedges to make up its 'whole' shape and
that same wedge can be used to change those shapes. To sharpen a knife, you
have to make the edge come to a true wedge shape. To do this you must remove
equal amounts of material on either side of the blade. ANYONE can sharpen a
knife. It's not a "magical gift", it's a SKILL (easily learned). I see 1 of
4 things when someone has brought me a knife that they tried to sharpen
unsuccessfully. They are listed as followed:
1) They held an equal angle on both sides but did not achieve a shallow
enough angle (23 degrees or lower) to actually cut something.
2) They did the proper angles, but did not remove the 'wire edge' (a tin
foil like piece of metal that lingers on a properly sharpened knife).
3) They used too fine a grit of sharpening stone to accomplish the task in a
reasonable amount of time and "gave up" because they can't sharpen a knife
(wrong attitude and wrong sharpening media).
4) Because they held unequal angles and keep removing metal without ever
meeting the other equal angle of the other side of the wedge. Thus removing
whatever previous work they did on the other side of the edge and having in
fact dulled the blade in the process.
To fix these problems, let's start with the basics. Here are the steps:
A) Use a good sharpening media that can accomplish the task as quickly as
possible and yet leave a fairly smooth cutting edge. (I`d suggest a medium
grit diamond stone from Ez-lap (tm)*Update DMT stones in Course grade is fine too ). A medium grit stone will often make a
blade sharp enough for utility use. Making it scalpel sharp will be
discussed later. The only difference between scalpel sharp and utility sharp
is polishing the edge to a mirror smooth toothless edge. Both are still the
same angled wedge, just different needs are met.
B) To hold a constant angle, use this trick. Put your index finger (on
really long blades add more fingers to support) behind the spine of the
blade (opposite the edge) and use that to control the angle of edge. It's
roughly about 23 degrees at the middle of the tip of the index finger and
about 17 degrees at the very tip. Use this to support the knife and you will
hold same angle on both sides of the edge.
C) To remove metal from the edge, you have to rotate the edge up against the
sharpening media. Do this clockwise from beginning of the edge to tip. Turn
over and repeat on the opposite side. When you get close to the tip , angle
the knife a little bit "up", as this evens the tip's thinness to match the
rest of the cutting edge thickness; hence a smoother cutting surface.
D) When you visually see a small tinfoil like wire edge along the full
length of your blade, you know that your knife has both angles meeting each
other in a uniform wedge. You now have to remove this 'wire edge'. To do so,
stroke the blade across the stone from end to end at an exaggerated angle
(about 35 degrees) until you see the wire break free from the edge.
*Note: The same thing can be accomplished with a butcher steel or ceramic
rod to break the edge. Congratulations! your knife is now 'utility' SHARP !
E) Now that your knife is sharp, you may cut paper and notices your blade
drags a bit. This means you need to "hone your blade". This can be done on a
fine (finer grit) stone. Gently stroke your blade across the fine stone till
you see the scratches on the edge becoming smaller and uniform. This is
lowering the "teeth" level of the blade to a lesser level of friction.
---Let me digress, If you are cutting rope you want a higher level of teeth.
To give an example try sawing a log with a razor blade. Now try using a saw
to cut a piece of paper. The amount of teeth you need in a blade has to do
with how "heavy" a material you are cutting. Keep testing the edge on
newspaper till you get through it without any drag. It's now 'common task'
SHARP!
F) Now you may want that scalpel edge that is so common on higher priced
custom and factory knives. Well it`s not hard to do. Keep in mind that a
razor edge, while extremely sharp, dulls quickly. To get a scalpel edge, you
must make a 'strop'. To do this obtain a piece of fairly thick, smooth
leather. Glue this leather (rough side down) to the back of your sharpening
stone or a block of wood. Rub in any hand lotion (good for any leather
product) and then follow up with white rouge (usually known as stainless
steel buffing compound ; found at ANY hardware type store). Do this till you
fill the length of the strop. Now take your edge and lay it flat against the
strop and "push" the knife away from the polishing surface (if you pull into
the strop, you wind up cutting it and making it damaged). Do this equally on
both sides till you see a mirror-like reflection. You now have an edge that
is almost friction free and can shave hair or cut with the precision of a
razor blade. After you use your knife, strop it back to life and you will
have to sharpen it less. When stropping doesn't work anymore, use the fine
stone. When that doesn't` work use the medium stone, after that coarse grit.
The whole purpose to proper sharpening is a safe knife is a SHARP knife and
when sharpening to remove as little as possible to lengthen the life of the
blade.
Ok now the 'survivalist' guide to improvised sharpening media....
****Improvised Sharpening Surfaces****
Smooth concrete (use with water) Sandpaper glued on glass or hard wood (use
dry) Bottom of uncoated (not glazed)ceramic coffee cup or ceramic pot, ect.
(use dry) Smooth round or flat quartz stone from a stream (use with oil or
water) Dremel (tm) tool with stone , rubber abrasive wheel (use dry and adjust speed as needed).
****Improvised Strops (for breaking the wire edge)****
Leather belt, rough side (or smooth side if you have strop compound), Dremel
(tm) tool and cloth wheel loaded with compound (high speed setting), Back of
note pad, the cardboard support (the rougher the better), Copper pipe (use
like a butcher steel till 'wire edge' breaks off), Soft wood (run edge
slowly through wood till 'wire edge' tears), The smooth tip of a file or any
other hard smooth steel (run square edge along surface), Another knife! Yes
it works . In fact, if you have two knives each with a 'wire edge', they
shear each other off. Do this with speed and SAFETY .
*****SAFETY*****
Well we can't discuss sharpening without discussing safety ...... My first
suggestion is buy a pair of Kevlar (tm) gloves sold in the fishing
department of most sporting goods stores. WEAR them. If you're using a motor
driven sharpener (ie: slack belt sander, sharpening wheel, buffer, Dremel
(tm) tool, ect.), USE goggles. Accidents DO happen! Have a full first aid
kit handy. ALWAYS put the cutting tool back in the sheath. NEVER leave an
unused edge laying around. You or someone else will get cut.
-----I digress. About 5 years ago, I had an Estwing (tm) hatchet. I was
packing for a camping trip, and I had the hatchet RAZOR sharp (literally)
and without a sheath. I left it on my sleeping bag and then the unthinkable
happened. I moved the sleeping bag and the hatchet fell right on my toes. I
never felt the cut, but I saw it as soon as I took a step. I had lots of
stitches and a well planned camping trip ruined. ALWAYS keep first aid an
arms length away. ALWAYS wear shoes when sharpening.
Wear gloves for better control and/or use the lanyard hole and lanyard if
your knife has one. Try to be sitting down or in a stable position when
sharpening. If you fall with your knife, throw your hand away from your body
but do NOT throw the knife away from you. You may loose it or injure
someone. Your mother always told you this, but don't run with a knife.
ALWAYS keep your knife super sharp. A cut with a sharp knife heals faster,
is less prone to infection and hurts a whole lot less. Not to forget to
mention that a well controlled knife is a SAFE knife.
Lastly this.....NEVER saw with your knife. Use slicing strokes and shear
thick materials with multiple long strokes. Using the sawing motion with a
knife edge dulls it rather quickly.
(Editing credit goes to Rodent , a Knife Forum Member.)
Copyright to Knifeman November 1996-2001 for use by Frugal Forums
*************
Sharpening FAQ
Knifeman
The subject of the following article is on -Sharpening- ( with both
improvised and & modern sharpening media ) .
*************Sharpening***************
When I was a in my late teens, I discovered my Grandfather's sharpening
stone. I had some scrap steel rectangles laying around the house, so I
decided to see if I could sharpen these blunt pieces of steel into usable
tools. I soon discovered sharpening was a skill. I spent hours trying
different ways to speed up what I was trying to accomplish. The following
article is what I learned that day and the lessons of years of sharpening
knives both professionally as well as in the woods and streets in desperate
need of a sharp tool. The first thing you need to understand about making
something "sharp", are angles. A wedge is man's oldest tool.(Notice how I
didn't say a knife?) The wedge is what can enter through a small slit and
leave removing a sliver to halve the intended material. When we think about
it just about any shape contains wedges to make up its 'whole' shape and
that same wedge can be used to change those shapes. To sharpen a knife, you
have to make the edge come to a true wedge shape. To do this you must remove
equal amounts of material on either side of the blade. ANYONE can sharpen a
knife. It's not a "magical gift", it's a SKILL (easily learned). I see 1 of
4 things when someone has brought me a knife that they tried to sharpen
unsuccessfully. They are listed as followed:
1) They held an equal angle on both sides but did not achieve a shallow
enough angle (23 degrees or lower) to actually cut something.
2) They did the proper angles, but did not remove the 'wire edge' (a tin
foil like piece of metal that lingers on a properly sharpened knife).
3) They used too fine a grit of sharpening stone to accomplish the task in a
reasonable amount of time and "gave up" because they can't sharpen a knife
(wrong attitude and wrong sharpening media).
4) Because they held unequal angles and keep removing metal without ever
meeting the other equal angle of the other side of the wedge. Thus removing
whatever previous work they did on the other side of the edge and having in
fact dulled the blade in the process.
To fix these problems, let's start with the basics. Here are the steps:
A) Use a good sharpening media that can accomplish the task as quickly as
possible and yet leave a fairly smooth cutting edge. (I`d suggest a medium
grit diamond stone from Ez-lap (tm)*Update DMT stones in Course grade is fine too ). A medium grit stone will often make a
blade sharp enough for utility use. Making it scalpel sharp will be
discussed later. The only difference between scalpel sharp and utility sharp
is polishing the edge to a mirror smooth toothless edge. Both are still the
same angled wedge, just different needs are met.
B) To hold a constant angle, use this trick. Put your index finger (on
really long blades add more fingers to support) behind the spine of the
blade (opposite the edge) and use that to control the angle of edge. It's
roughly about 23 degrees at the middle of the tip of the index finger and
about 17 degrees at the very tip. Use this to support the knife and you will
hold same angle on both sides of the edge.
C) To remove metal from the edge, you have to rotate the edge up against the
sharpening media. Do this clockwise from beginning of the edge to tip. Turn
over and repeat on the opposite side. When you get close to the tip , angle
the knife a little bit "up", as this evens the tip's thinness to match the
rest of the cutting edge thickness; hence a smoother cutting surface.
D) When you visually see a small tinfoil like wire edge along the full
length of your blade, you know that your knife has both angles meeting each
other in a uniform wedge. You now have to remove this 'wire edge'. To do so,
stroke the blade across the stone from end to end at an exaggerated angle
(about 35 degrees) until you see the wire break free from the edge.
*Note: The same thing can be accomplished with a butcher steel or ceramic
rod to break the edge. Congratulations! your knife is now 'utility' SHARP !
E) Now that your knife is sharp, you may cut paper and notices your blade
drags a bit. This means you need to "hone your blade". This can be done on a
fine (finer grit) stone. Gently stroke your blade across the fine stone till
you see the scratches on the edge becoming smaller and uniform. This is
lowering the "teeth" level of the blade to a lesser level of friction.
---Let me digress, If you are cutting rope you want a higher level of teeth.
To give an example try sawing a log with a razor blade. Now try using a saw
to cut a piece of paper. The amount of teeth you need in a blade has to do
with how "heavy" a material you are cutting. Keep testing the edge on
newspaper till you get through it without any drag. It's now 'common task'
SHARP!
F) Now you may want that scalpel edge that is so common on higher priced
custom and factory knives. Well it`s not hard to do. Keep in mind that a
razor edge, while extremely sharp, dulls quickly. To get a scalpel edge, you
must make a 'strop'. To do this obtain a piece of fairly thick, smooth
leather. Glue this leather (rough side down) to the back of your sharpening
stone or a block of wood. Rub in any hand lotion (good for any leather
product) and then follow up with white rouge (usually known as stainless
steel buffing compound ; found at ANY hardware type store). Do this till you
fill the length of the strop. Now take your edge and lay it flat against the
strop and "push" the knife away from the polishing surface (if you pull into
the strop, you wind up cutting it and making it damaged). Do this equally on
both sides till you see a mirror-like reflection. You now have an edge that
is almost friction free and can shave hair or cut with the precision of a
razor blade. After you use your knife, strop it back to life and you will
have to sharpen it less. When stropping doesn't work anymore, use the fine
stone. When that doesn't` work use the medium stone, after that coarse grit.
The whole purpose to proper sharpening is a safe knife is a SHARP knife and
when sharpening to remove as little as possible to lengthen the life of the
blade.
Ok now the 'survivalist' guide to improvised sharpening media....
****Improvised Sharpening Surfaces****
Smooth concrete (use with water) Sandpaper glued on glass or hard wood (use
dry) Bottom of uncoated (not glazed)ceramic coffee cup or ceramic pot, ect.
(use dry) Smooth round or flat quartz stone from a stream (use with oil or
water) Dremel (tm) tool with stone , rubber abrasive wheel (use dry and adjust speed as needed).
****Improvised Strops (for breaking the wire edge)****
Leather belt, rough side (or smooth side if you have strop compound), Dremel
(tm) tool and cloth wheel loaded with compound (high speed setting), Back of
note pad, the cardboard support (the rougher the better), Copper pipe (use
like a butcher steel till 'wire edge' breaks off), Soft wood (run edge
slowly through wood till 'wire edge' tears), The smooth tip of a file or any
other hard smooth steel (run square edge along surface), Another knife! Yes
it works . In fact, if you have two knives each with a 'wire edge', they
shear each other off. Do this with speed and SAFETY .
*****SAFETY*****
Well we can't discuss sharpening without discussing safety ...... My first
suggestion is buy a pair of Kevlar (tm) gloves sold in the fishing
department of most sporting goods stores. WEAR them. If you're using a motor
driven sharpener (ie: slack belt sander, sharpening wheel, buffer, Dremel
(tm) tool, ect.), USE goggles. Accidents DO happen! Have a full first aid
kit handy. ALWAYS put the cutting tool back in the sheath. NEVER leave an
unused edge laying around. You or someone else will get cut.
-----I digress. About 5 years ago, I had an Estwing (tm) hatchet. I was
packing for a camping trip, and I had the hatchet RAZOR sharp (literally)
and without a sheath. I left it on my sleeping bag and then the unthinkable
happened. I moved the sleeping bag and the hatchet fell right on my toes. I
never felt the cut, but I saw it as soon as I took a step. I had lots of
stitches and a well planned camping trip ruined. ALWAYS keep first aid an
arms length away. ALWAYS wear shoes when sharpening.
Wear gloves for better control and/or use the lanyard hole and lanyard if
your knife has one. Try to be sitting down or in a stable position when
sharpening. If you fall with your knife, throw your hand away from your body
but do NOT throw the knife away from you. You may loose it or injure
someone. Your mother always told you this, but don't run with a knife.
ALWAYS keep your knife super sharp. A cut with a sharp knife heals faster,
is less prone to infection and hurts a whole lot less. Not to forget to
mention that a well controlled knife is a SAFE knife.
Lastly this.....NEVER saw with your knife. Use slicing strokes and shear
thick materials with multiple long strokes. Using the sawing motion with a
knife edge dulls it rather quickly.
(Editing credit goes to Rodent , a Knife Forum Member.)
Copyright to Knifeman November 1996-2001 for use by Frugal Forums
*************
