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This a long document, make use of the links below to
jump to the appropriate sections.
The Blade
1. Making the template
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2. Profiling the blade
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Stick the photocopy of the
design unto some mild steel sheet; 0.5 mm thick, thick galvanized sheet
also works. Use some PVA wood glue; spread thinly, else the paper will
buckle. I use a rubber roller to spread the glue. Leave it to dry for
about twenty minutes and cut the design from the sheet with a hacksaw or
band saw. Cut as close to the outline as possible without going into the
outline.
Grind up to the line with a
60-grit belt, or use files. If you use a grinder, be careful not to
overheat the template, else the paper will burn off! A wet cloth or
towel is a good way to keep the template cool without damaging the
water-soluble glue. Just place the template paper side up on the wet
towel every few seconds.
Punch small indentations in the
template where all the holes should be drilled. Drill through with a 2
mm drill, de-burr the drilled holes with a handheld sharp drill bit that
is larger than the drilled holes.
Drill a small hole near the tip
of the template to hang it on a hook. In a short while, you will have a
series of hooks against your wall, each holding a number of templates.
Mark the template with a marking pen. Use a simple code, such a gsk 1,
which stands for “gentleman’s side knife nr 1” The next side knife you
design will be gsk 2 Other knives can be marked “sk” (skinners) “lc”
(large/combat) “d” (daggers) etc.
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Place the prepared template on
3.2 – 3.5 mm tool steel (O1 or D2) or hardenable stainless steel (440 b
or c, 12c27 or similar). If you are using clean, surface ground steel,
spray a coat of engineer’s layout spray on the steel (use the type that
must be removed with an organic solvent, the water soluble type will
wash away as soon as you dunk the blade in water to cool it down.) This
will enable you to see the scribed line very clearly when grinding the
blade. Hold the template tight against the steel stock, or use vice grip
locking pliers. Scribe all round the template with a sharp scribe.
Remove the template from the
billet and saw off most of the unwanted material. If the blade width and
the stock width are close enough you only need to cut the steel to
length. Be careful when cutting to leave the scribed line intact.
Fit your belt grinder with a 60
grit belt and a horizontal rest. Grind up to the scribed outline. To
grind hollows on the blade profile, adjust the tracking of the grinder’s
wheels for the belt to run about 3 mm of the edge of the contact wheel.
This will protect the wheel from being damaged by the sharp edge on the
blade and the belt will bend slightly around the corner, allowing you to
quite accurately grinding the hollows without getting sharp corners
where the edge of the belt dig into the steel.
Replace the 60 grit belt with a
180 grit belt and run all around the blade, making sure that the profile
is smooth and as close to the outline as possible.
De-burr the blade with a sharp
needle file, I sometimes use a Stanley knife, a quick cut at a 45-degree
angle will remove the burr.
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3. Deburring and flattening
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4. Marking the cutting edge
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If you are using hot rolled
sheet with a black oxide layer on it, it is now an excellent time to
clean it up. Put some swimming pool grade hydrochloric acid in a plastic
tray. (Do this outside) Place the blade in the acid for a few minutes.
The acid will eat away the oxides, revealing any slight pitting from the
rolling process. Another reason for doing this is the fact that the
oxides are much harder than the underlying steel and tends to clog
grinding belts. Chemically removing the oxides will save you the cost of
a number of belts in the long run.
Place the blade blank on a
surface plate and make sure that is flat. As the steel has not been
hardened at this stage, you should be able to straighten it by bending
it in your hands. Stubborn bends can be removed by placing the blade on
a piece of leather or soft wood, bulge upwards and giving it a sharp rap
with a smooth faced hammer right on the offending bulge.
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Accurately measure the thickness
of the blade. My blade is 3.5 mm thick. Deduct from this the thickness
of the cutting edge, 0.6 mm. Divide the answer by 2. (3.5-0.6)/2 = 1.45
mm for the steel I used. This is the amount of steel that must be
removed from the thickness of the blade to get a cutting edge of an
appropriate thickness.
If you have a height gauge, set
it to the size you have calculated and scribe the cutting edge of the
blade. Flip the blade over and scribe again. You will now have two
parallel lines along the cutting side of your blade blank. If you do not
have a height gauge you can use your Vernier calliper. Carefully grind
one leg about 1.5 mm shorter than the other. Then grind a 45 deg cutting
edge on the shorter leg. Set the calliper at the right distance as
calculated and tighten the locking screw. Rest the longer leg against
the side of the blade and use the shorter, sharpened leg as a scribe.
Scribe the rear of the handle as
well, this will the mark for tapering the tang. These two lines must be
0.8 to 0.9 mm apart. (The Guild standard for a tapered tang knife is 0.9
mm maximum tang thickness at the end of the handle.
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5. Marking & Drilling holes
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6. Tapering the tang
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The reason for marking the
cutting edge before drilling the holes is that the blade invariably
bends slightly from punching the location of the holes and under the
pressure and heat from the drilling process. Drilling the larger holes
also leaves a large burr that must be removed before the cutting edge
can be marked, should you decide to drill first and mark later.
Place the template on the blade
blank. Use a clutch pencil and mark the location of all the holes. Punch
these marks; you only need to make a small indentation. For most of my
knives, I use 2 mm pinning, which is why I use a 2 mm drill. Select a
drill that is the same size as the pinning you want to use.
Note: If you use different sized
pinning for bolster and handle, make sure that you use the right drill
in the right place! A small hole can always be made larger, but a large
hole cannot be made smaller without resorting to extreme measures.
(There is a simple way of fixing too large holes which is discussed
under the section on fitting guards)
Drill all the holes with the
appropriate drill. Use a 2.5 or 3 mm drill to drill the holes in the
middle of the handle. This makes it much easier to enlarge them with a
larger drill.
Fit a 10 mm drill and drill the
three large holes in the handle.
There are three reasons for
drilling large holes through the tang:
Drilling these holes reduces the
amount of material to be removed when grinding the tang taper.
It lightens the handle of the
blade.
The holes will be filled with
epoxy when gluing the handle onto the blade, providing better adhesion
of the handles.
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Put a 200 mm contact wheel and
60 grit belt on the belt grinder. Grind small bevels on the handle end
of the blade, up to the scribed lines. Put a 400 grit belt on, and do a
quick pass on the bevels to make them shine.
Back to the 60 grit. Fit a
horizontal rest to the grinder, moving it as close as possible to the
contact wheel. Take a piece of hard wood, about three inches long, two
inches wide and half an inch thick. Place it on the rest and grind a
hollow on the end. Place the blade on the rest and use the push stick
you just made. Grind a hollow in the tang end of the blade. The hollow
should begin in the bolster area and end level with the polished bevel.
Be careful not to run over the tang edges, as this will cause a gap
between the handle slabs and the tang.
Remove the horizontal rest, fit
a platen to your grinder and put on a 2” 60 grit belt. The operation
that follows has caused me the greatest amount of hurt of all the
grinding actions one has to perform on a knife. Place a magnet on the
tang. I use a welding magnet, the triangular one with the hole in the
centre. Grab the blade by its tip with your clever hand. Carefully bring
the tang to bear against the belt. Watch that top hand, a 60 grit belt
eats fingernails like an elephant eats grass. The trick is to have the
whole of the tang against the belt and to put pressure on the side you
want to remove more steel, as I am using a vertical platen, with the
blade on top, this is the bottom. DO NOT lift part of the tang off the
belt, as this will cause multiple bevels on the tang. Grind for a few
seconds, lift the tang of the belt and inspect the results. Apply
pressure on the side that needs a bit more work. The end result should
be an even bevel running from the front of the bolsters right up to the
end of the tang, with a slight hollow starting in the middle of the
bolster area and ending ½” to 1” from the tang end.
Once you have done both sides of
the tang, it is time to do the blade. If you are using surface ground
stock this is not necessary, but if your stock comes to you hot rolled
with a black layer of oxides on it you would have chemically cleaned it
by now. If there is any pitting in the ricasso and blade area, the
surrounding metal will have to be removed. (You can not grind away a
hole!) In most cases, a light touch on a sharp belt is all that is
needed.
Put on a 180-grit 2” belt and
clean up the 60 grit marks, using the same method with the magnet.
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7. Hollow grinding the blade
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This part gives the beginning
knifemaker the most stress. (And me, as writer, the greatest headache)
How does one describe the subtle movements required to do hollow
grinding? Here goes, and I take no responsibility for the next twenty
blades you are going to grind! By the time you grind blade twenty-one
you will have forgotten all I have written here and have found your own
way.
Fit a contact wheel of the
correct diameter on the belt grinder. (See the appendices for a table of
grind height, blade thickness and wheel diameter relationships.) Fit a
used 60 grit belt on the machine.
Use a carpenter’s marking gauge
to scribe the grind line you are aiming for on the blade. You now have
three lines per side on the blade: The line indicating the cutting edge,
the grind line, and an imaginary arc, connecting the edge and the grind
line. The art of hollow grinding is the removal of the unwanted material
above the imaginary arc, thus making it real. The arc is a section of a
circle with the diameter of the contact wheel.
You will also have to make a
push rod or stick. Mine is a 1”x 4”x 1/2” piece of wood, with a step cut
into one end. I have also seen a wooden file handle with a brass rod
inserted. A step is cut into the end of the rod.
Mark the position of the choil
(where the cutting edge must start) clearly, else your edge might run
into the ricasso or bolster area.
Present the blade edge upwards
to the wheel. Grind a 45-degree bevel on the cutting edge, up to the
scribed line indicating the thickness of the edge, from the choil to the
tip. Do the other side as well. Repeat with a 180-grit belt, going right
up to the line. There is a twofold reason for doing this: The sharp edge
of the steel is blunted, making your belts last longer. The shiny bevel
contrasts with the hollow in the blade, making it very easy to see how
much further you have to go.
Fit a 36 grit belt, or a 60 grit
3M 977 ® ceramic belt, on the machine.
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Pictures with captions:
Cutting edge upwards, support
the blade with the push rod.
Grind the run outs on the
ricasso first, making sure that they are symmetrical.
Pull tang towards you as you
near the tip / use a rolling wrist action.
The run outs on the spine should
be symmetrical as well.
Grind with 36, 60-grit belts,
finish with 180 grit or A100 belt.
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Heat treatment
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Polishing the blade
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At this stage, your blade is
still very soft. If you have an electrical or gas furnace you can now go
ahead and harden the blade, else you will have to send it to a
specialist Heat Treatment Company. (Sometimes a fellow knifemaker will
do it for you as part of a batch of blades.)
The heat treatment processes are
fully discussed in the materials section.
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The hardened blade will have a
layer of oxides on it, the thickness of which will depend on the heat
treatment process used. If you used stainless steel a quick soak in
diluted hydrochloric acid will get rid this layer.
Put the platen your grinder and
fit a 180-grit belt. Clean up the tang. If you have a disc grinder use
it instead. Repeat the process with a 400-grit belt. Fit the same
contact wheel you used to grind the hollows and clean up the hollows of
the blade.
Keep the blade cool; any
discoloration of the blade is a sign that the blade is getting too hot.
Polish the blade hollows using
180 grit, A45, A30 and A16 belts. Use even pressure, do not let the
corner of the belt rub on the blade, use the full surface of the belt,
else you will get ridges on the blade.
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The blade after it has been finished to 1200 grit
using an A16 belt
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Clamp the blade by the tang in a
horizontal position in a swivel vice or blade clamp. Start with 400-grit
paper and a flat sanding block and sand the ricasso and bolster area.
Keep the block flat against the steel. Move on to 800 grit paper,
working at a slight angle to the previous grade paper. This will clearly
show up any scratches that must still be removed. Do both sides of the
blade.
Take a rounded sanding block,
the one with a radius that is slightly smaller than that of the contact
wheel you used to grind the blade hollows and 800-grit paper. By using a
block with a smaller radius than that of the grinding wheel you ensure
that the crisp edge of grind line is not
rounded over. Use a pulling motion to remove all the vertical scratches
in the blade hollow.
Do the flats with 1200-grit
paper, using an even motion, keeping the sanding block flat against the
steel.
Use the rounded block that has
the same radius as the contact wheel and sand the blade hollows with an
even motion. It should be an uninterrupted movement from the ricasso to
the blade tip. Move the paper on the sanding block, fresh, unused paper
should be used with each stroke. Do both sides of the blade. I use
kerosene / paraffin as a lubricant.
The 1500 grit is the most critical. Be sure to use a pulling motion
only, and always in the same direction. Do not stop in the middle of a
motion as you will get marks running in a different direction.
I use kerosene / paraffin as a lubricant.
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Here is a full size picture of the blade, finished to 1500
grit.
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There are a number of logo
etching procedures and methods one can use. The method I use is cheap,
effective, and cannot be copied or forged / counterfeited.
Clean the blade with some
acetone. Heat it to about 70 deg C and apply a thin layer of wax resist
(etching ground) on the area where the mark should be. (Blade edge down,
tip to the left!) Let the blade cool to room temperature. Use a
sharpened brass rod and make your signature. Use enough pressure so the
writing goes right through the resist layer to the steel. (See the
chapter on etching for a wax resist formula)
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Place a few drops of ferric
chloride on the signature, making sure that it does not run unto any
part of the blade not covered by the resist. You might need to tilt the
blade slightly by placing a matchstick or wedge underneath the cutting
edge if the mark is on the hollow of the blade. After a few minutes you
will notice bubbles appearing, this is a sign that the steel is being
eaten away. (If the ferric chloride solution is too weak, or nothing
seems to be happening after half an hour, use a piece of tissue paper to
blot up the mordant and place a few drops of Aqua Regia on the
signature)
I usually place a rod or wedge
under the edge to tilt it somewhat, keeping the drop of Ferric Chloride
where it should be.
Check the depth of the etched
signature with a sharp needle. It should feel like the needle is running
in a shallow groove and cannot be moved sideways.
Carefully blot up the mordant
with some tissue paper. Rinse the blade under running water. Remove the
wax resist by heating the blade slightly and wiping with a piece of
tissue, or apply some kerosene or turpentine which will dissolve the
wax.
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The finished
logo (my signature)
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Put the blade back in the vice
or blade clamp and give it a quick once over with the 1500
grit paper. Cover the blade up to the ricasso with a layer of masking
tape to protect the fine finish through the following steps.
Cut two pieces of bronze or 303
stainless, each about 3.5 mm thick and slightly larger than the area it
must cover on the blade. Grind the inside of each piece clean and flat
on the vertical platen using 60 and 180 grit belts.
True the surface on a disk
grinder fitted with 180 grit paper, or place a sheet of 180 grit paper
on a surface plate and hand sand the inside surfaces flat and true.
Sanding in one direction, then turning the bolster at an angle of 45
degrees and applying a few strokes will show if the surface is flat. The
new scratches should cover the whole surface of the bolster. If the
there are places where the previous scratches are showing it means that
those places are deeper than the rest. If these are on opposite sides of
the bolster, it is an indication that you are rocking the bolster when
sanding, applying pressure on first the one edge, then the other. Use
even pressure and work at right angles to correct this.
Dovetails:
I use dovetailed bolsters on all
my knives. To do dovetails you need either a grinding slope or a jig. A
grinding slope is a piece of metal that has been milled at a 30 degree
angle and is used on the disk grinder’s horizontal rest or on belt
grinder’s rest when the grinder is fitted with a vertical platen.
The dovetail jig is made of two
milled bars of steel, with guide pins at either end. The piece that must
be cut at an angle is placed between the bars with the edge that must be
cut protruding slightly, the screws are tightened and the whole setup is
placed on the grinder’s rest with a vertical platen in place.
This picture show the angle of the dovetail being ground
with the aid of a dovetail jig. I usually rough grind with 60 grit belt,
then touch up the grinds on the disk grinder. Make sure that you keep
your hands steady as the slightest movement sideways will give a rounded
surface, which will lead to further problems when you have to fit the
handles.
Bolster alignment and drilling:
Use a bolster alignment clamp to make sure that both
bolsters go on at the same angle and in the same place. (A bolster
alignment clamp is made from two tool steel bars with guide pins and
screws to tighten it up.)
Make sure that the alignment clamp is parallel to the pins
used on the handle slabs, and not to the pins used to fasten the
bolster! If you are using dovetail bolsters, ensure that the pins are
not to close to the dovetail as you might bend the dovetail over when
peening.
Clamp one bolster to the blade, against the alignment
clamp as shown, and spot mark the pin holes by clamping the vice grip in
your drilling vice and drilling small indentations on the inside of the
bolster with the drill press.
Do the same on the other bolster, remember to clamp it
on the other side!
Drill the holes through, fit one bolster to the blade
using fitting pins, scribe the top and bottom edges. Do the same with
the other bolster.
Fit one bolster in
place with loose pins and scribe the blade outline top and bottom on the
bolster. Do the same with the other bolster. Use a scribe to mark the
face or front of the one bolster. I do this free hand, but if you really
must match the design perfectly you can trace the bolster on a piece of
paper and make a template in the same way as the blade template. You can
then use this to scribe the front of the bolster.Now you need to profile the bolsters, and shape the front
shoulder.
This is done using a 36 or 60 grit belt, and the
horizontal rest, taking
care not to run over the scribed lines.
Shape the front shoulder on one bolster only. Pin the two
bolsters together (do not peen!) and scribe the shoulder onto the other
bolster. Profile the other bolster to the scribed lines. Put them
together again with pins and polish the front shoulders of both at the
same time, going from 60, 180, 400, A45 to A16.
Hand finish the front face with 1200 grit, the 1500 grit
paper and buff. (If you want a satin finished bolster, omit the
buffing)
Touch the bolster insides on the disk grinder to ensure
that they are flat.
The pinning should be of the
same material as the bolster or a very close match. (For 303 stainless
steel bolsters, I use 308 TIG welding rods and bronze TIG
rods for bronze). Cut pinning to length slightly longer than the
thickness of the blade and the two bolsters combined. Clean the inside
of the bolsters and the blade and fit the bolsters to the blade with the
pins. Cut the pins to length, there should be 2 mm of pinning extending
on both sides if you are using 2 mm pinning. Place the assembly on an
anvil or block of steel and peen, the pins. My table anvil has a small
indentation on its face, which helps to round over the bottom end of the
pins while the hammer is doing the work on the top end. Turn the blade
over and peen the other side. I use a large ball peen hammer. It is
important that you do not hammer close or on the bolster face and back,
one missed blow will cause the polished bolster face to crinkle, or put
a dent in the dovetailed back.
Put a sharp 60 grit belt on the grinder and shape the
bolster. Be careful not to overheat as this may cause the bolster to
warp. Use a steady rolling motion to put an even curve on the bolster.
Do not use belts that are worn in the center as the belt edges will dig
into the bolster.
Fit a sixty-grit belt to the
grinder. Grind the top and bottom edges of the bolsters. Use a rolling
motion to put an even radius on the corners. It is important to keep the
bolsters cool as excessive heat may cause them to warp. Remove more
metal off the front of the bolster, so the bolsters taper from back to
front when viewed from the spine of the blade. Look at the bolsters from
the blade tip and from the tang tip to check their symmetry, the radius
should be same on both sides. When you are satisfied with the shape and
thickness of the bolsters, you may change to a 180-grit belt and remove
the 60 grit grind marks. Repeat with a 400-grit belt. Do not use
belts that are worn in the centre, as the belt edges will dig into the
bolster.
Run the knife vertically to the wheel to level the bolster
and blade on top and on the bottom. When you are satisfied with the
shape you can go on to 180, 400, A30, A16.
Here is a picture of the knife with the bolster shaped
and polished to A16 on the grinder.
Next step is to hand finish the bolsters. Clamp the tang
in the vice, wipe the blade with acetone and cover the blade both sides
with a layer of masking tape. Polish the bolsters with 1200 grit paper.
Make sure that you work lengthwise, then across as this will show up any
remaining scratches clearly.
Repeat with 1500 grit paper. Cover the bolster and blade
with a layer of masking tape after wiping with acetone to ensure there
is no grit that may give you trouble later on.Use
a sharp knife to cut the tape on the back edge of the bolster, where the
handle will go into the dovetail. Use a small triangular file to clean
up the inside of the dovetail.
Note: Because I usually work with handle
materials that are not very heat tolerant, I finish the bolster before
fitting the handle. You may want to shape and finish the bolster and
handle in one go. First rough shape the bolster to prevent unnecessary
heating of the handle materials at the joint. Should you do it this
way you need to pay extra attention to the area where the bolster and
handle meet as the softer handle material will wear out faster than
the bolster, causing a slight dip or hollow. Use a rubber or leather
sanding block to prevent this.
You are now ready to do the handle.
I decided to use jigged
bone scales for the handle.
The bone was cut to size, flattened, and the dovetail cut
using the same jig as for the bolsters. (In the case of the bolsters I
had the inside upwards, on the scales I put the inside down in the
jig.)
After the bone was jigged and coloured, (click
here for pictures) I drilled the pin holes using
drilling clamps.
Place the two slabs on the tang
to measure the length of the pins needed. Cut the pins a few mm too
long. Fit the pins to the one slab, the ends should be flush with the
inside of the slab. Wipe both slabs and the tang with acetone. Mix and
apply clear epoxy to the slab with the pins. Fit the slab to the tang
and push the pins through the tang, apply epoxy to the tang, make sure
that all the large holes in the tang are filled. Fit the other slab and
push the pins through. Clamp with two small G clamps until the glue has
set.
I use five minute epoxy, which
sets in three minutes in hot weather, and takes forever in winter.
When the glue has set you can
start shaping the handle on a 60 grit belt as shown
below.
Shaping the handle
Cut the pins flush with the
handle, grind the handle on the contact wheel using a 36-grit belt to
get the rough shape. Switch to a 60-grit belt and refine the handle
shape. Turn the knife with its spine towards the wheel and carefully
remove the handle material where it extends past the tang, stop as soon
as the belt touches the tang. Do the same on the bottom. You might find
that the handle now has a flat surface all round.
Break the corner and round the
handle. Be careful not to remove too much material.
Turn the knife blade upwards and
very carefully grind the handle / bolster connection. You do not want to
touch the polished bolster with the belt. The handle should have an even
radius, the same as the wheel’s, from the bolster to the level of the
handle proper.
Switch to a 180 grit belt and
run round the handle, removing any scratches on the tang.
The knife is ready for final
finishing by hand, using files and sandpaper.
Place the blade in the swivel
vice and do the final shaping by hand, using a second cut and a smooth
file. Bring the level of the handle flush with the masking tape, or as
close as you can get, with a smooth file. (Area indicated by the arrow)
Use strips of sanding paper,
starting with 180-grit, and a rubber sanding-block to remove the file
marks. Wrap a piece of paper round your finger or use a half round
sanding block to work on the radius where the handle and bolster meet.
Fit a 400-grit belt on the
grinder and run round the tang, removing all the 180 grit marks. Sand
the handle with 400 grit paper, paying careful attention the top of the
pins. They should be level with the handle material, and scratch free.
Use 800-grit paper, polishing
the exposed tang as well. Because bone is porous, you might not want to
buff it, it is therefore a good idea to go up to 1200-grit.
If you do decide to buff the
handle, you should use a greaseless buffing compound on a unstitched
muslin wheel.
Remove the masking tape, use a
good quality liquid wax or gun stock oil on a clean cloth to remove any
buffing residue and to bring the handle to a fine lustre.
All that is left is to make a sheath, remove the
masking tape and sharpen the blade.
The Finished Knife
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Alphabetical index
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