Oded
03-05-2005, 02:03 PM
Guys... this is not me instruction you but me sharing my expirience.
I would be happy to hear if you come up with a better / easier method for any of the stages... Thanks.
Getting the Right Size Wood Blank:
My own handle measures 150mm long, 28mm x 24mm at the back and 24 x 21mm at the front. See drawing 2A/B.
This is a relatively large handle and you might want to experiment. To give some idea, here are the sizes of other handles that I have:
Watanabe sample handle: 150mm long, 24 x 19.5 back, 22 x 18mm front.
Suisin Sakimaru Tako handle: 145mm long, 22.5 x 18mm back.
Suisin Funayuki Deba handle: 141mm long, 27. x 22.5mm back.
Obviously, you need to find a slightly larger wood blank. Wood turnery supplies are a good place to start and cue blank supplier could be another option. (I think cue blanks tend to be 1.5” x 1.5” – just perfect).
Boring
Japanese knife maker use the following method: They hold the handle blank by hand and use a lathe to horizontally bore the handle. How do they manage to get the hole true and parallel to the handle axis is simply beyond me. Once the handle is drilled they push a red hot, tang shaped piece of iron into the hole. The heated iron burns the wood and creates a tang shaped hole.
At the time I created my own handle I was not aware of this method and did not have a tang shaped iron. Even if I did, I would not use such method with the notoriously brittle Snakewood (they do use it on Ebony apparently).
Instead, I have used a drill press. Obviously, this meant two things:
1. I had pretty much to guess what is happening inside the handle.
2. I knew that I will need to make a hole larger then the tang and use epoxy cement rather then really on tight fit.
First, I made a 1:1 drawing of the tang and using a calliper marked the points were the thickness of the tang was 3, 3.5, 4, 4,5, 5 etc. See drawing 1B for an example.
I drilled 5 2mm holes (see drawing 1A) about 50mm deep. I then drilled holes 2,3,4 with a long series 3.5mm drill to a depth similar to the tang’s length.
I continued using increasingly larger diameter drill bits and reduced the depth of drilling in accordance with my drawing. At a certain point I also started drilling through holes 1 and 5; the exact point will be according to the individual tang.
Once finished came long hours of smoothing the holes inside with a rat tale rasp (the coarsest and longest I could find) until I could insert the tang freely.
Few Words on Planning and Planes
I am sure that as lovers of sharp metal we all understand the importance of a sharp plane blade.
However, it is also critical to have a well fettled (tuned) plane in general. The most critical point in my mind is the sole flatness. A properly tuned plane will be able to take .0005” shavings though if you only manage to go down to 0.001” that’s fine. I definitely recommend taking shaving no larger then 0.001” when working on the handle.
You can do without a plane altogether and use a coarse sand paper bonded to anything flat instead but the result are not the same – the flat sides will be somewhat rounded, parallel sides will not be really parallel etc.
Planning direction is important in nearly all timber species. Exotic timbers such as Cocobolo tend to have interlocking grains which means that in some instances neither direction is ‘right’ and whatever you do you end up with ugly tear outs.
The solution is to create a micro bevel on the flat side of the blade at around 25 deg. The pitch angle will be 70deg. ( 45 (the blade angle) + 25 (micro bevel) ) introducing a scraping motion which will normally tackle most difficult grain timber. Of course, the blades included angle will be around 50deg meaning you need to put more effort in planning Terry Gordon’s planes, made with Australian timbers in mind allow you to use the blade bevel up as well as down thus increasing the pitch angle without increasing the blade’s included angle. I have yet to try them myself but heard lots of good things about them.
From Rectangle to Octagon.
If you cut an octagon out of perfect square is very easy to have it equilateral with 8 135deg. Angles.
However, our octagon is cut from a rectangle rather then a square. This means you can have either:
An octagon with 8 x 135deg angles as in See drawing 4B but then the vertical sides (A in the drawing) will be bigger (or smaller) then the horizontal sides. The corner can be made similar to either but not both..
An equilateral octagon as in drawing 4A where 4 angles (B) are larger then 135 deg. and four angles A are smaller then 135deg.
The first version is obviously easier to make and in fact all Japanese handles are made in a similar pattern. The Suisin handles have small corners and can be expressed as A> B > C. The Watanabe has larger corners so B = C, A > B and A > C.
I have made few initial samples similar to that and was not really satisfied. At that time I have not seen a Japanese handle with my own eyes and looking at the pictures on web site I mistakenly thought that they are indeed closer to form 4A.
So, if you are satisfied with form A, your life is going to be rather simple: Run your blank on a router table with a 45deg bevel cutter. Make sure you are cutting the correct size bevel. I would say that as a starting point have your cutter protruding about 5mm from the table surface, 6mm at the most smaller if your handle is smaller then mine. You can always increase it and do a second routing if it is too small.
If you are like me, and want perfectionism you will be opting for the equilateral octagon of drawing 4A, which does look better.
But how do you cut bevel of 40 and 50 degrees (just an example; exact number will vary of course)?
The way I did it is by using a hand plane (I use a 5 ˝ Lie Nielsen for just about anything) and tilting the blade to one side. Taking a few careful shaving from the corners eventually modified the angles. This is very much a trial and error process and as slow as it may sound, I would recommend taking very frequent measurements. I did two shaving per side all around, and then measured each side. This way I could catch up and correct in time any mistake.
It is definitely a long and slow process and recommended for either hopeless perfectionist or plain masochist, two distinct groups I probably belong to myself.
Tapering the Handle.
I have used here a technique called stopped or partial shavings. Have a look at drawing 3. Assuming that your planning direction is from back to front, you take a couple of shaving starting 1” from the front, another couple of shaving 2” from the front etc, ending with a couple of through shaving to smooth it all out. Repeat for each the 8 sides and measure. Do it enough and you have got your tapering. Again, constant measuring will ensure you do not overdo one side.
If your planning direction is from front to end you will have to start at the front and lift the plane, while still moving forward in order to create the partial shave. It is critical not to stop the forward movement too early. This will take some practice so unless you are familiar with the technique I’d recommend practising on some off-cuts.
Finishing:
I have used the standard sandpaper and then micro-mesh all the way up to 12,000 (~= 4000 in sand paper grit). I have mentioned micromesh in the past so suffice to say that the result I get from using it is a highly polished wood.
Fish has recommended using Pumice, Rottenstone, Tripoli and White Diamond. I have ordered that stuff but would recommend asking Fish (on KF) how to use them since I do not know myself.
Coming next: Glue-up
http://i2.photobucket.com/albums/y36/carbonrider/knifehandle1.jpg
http://i2.photobucket.com/albums/y36/carbonrider/knifehandle3.jpg
http://i2.photobucket.com/albums/y36/carbonrider/knifehandle2.jpg
I would be happy to hear if you come up with a better / easier method for any of the stages... Thanks.
Getting the Right Size Wood Blank:
My own handle measures 150mm long, 28mm x 24mm at the back and 24 x 21mm at the front. See drawing 2A/B.
This is a relatively large handle and you might want to experiment. To give some idea, here are the sizes of other handles that I have:
Watanabe sample handle: 150mm long, 24 x 19.5 back, 22 x 18mm front.
Suisin Sakimaru Tako handle: 145mm long, 22.5 x 18mm back.
Suisin Funayuki Deba handle: 141mm long, 27. x 22.5mm back.
Obviously, you need to find a slightly larger wood blank. Wood turnery supplies are a good place to start and cue blank supplier could be another option. (I think cue blanks tend to be 1.5” x 1.5” – just perfect).
Boring
Japanese knife maker use the following method: They hold the handle blank by hand and use a lathe to horizontally bore the handle. How do they manage to get the hole true and parallel to the handle axis is simply beyond me. Once the handle is drilled they push a red hot, tang shaped piece of iron into the hole. The heated iron burns the wood and creates a tang shaped hole.
At the time I created my own handle I was not aware of this method and did not have a tang shaped iron. Even if I did, I would not use such method with the notoriously brittle Snakewood (they do use it on Ebony apparently).
Instead, I have used a drill press. Obviously, this meant two things:
1. I had pretty much to guess what is happening inside the handle.
2. I knew that I will need to make a hole larger then the tang and use epoxy cement rather then really on tight fit.
First, I made a 1:1 drawing of the tang and using a calliper marked the points were the thickness of the tang was 3, 3.5, 4, 4,5, 5 etc. See drawing 1B for an example.
I drilled 5 2mm holes (see drawing 1A) about 50mm deep. I then drilled holes 2,3,4 with a long series 3.5mm drill to a depth similar to the tang’s length.
I continued using increasingly larger diameter drill bits and reduced the depth of drilling in accordance with my drawing. At a certain point I also started drilling through holes 1 and 5; the exact point will be according to the individual tang.
Once finished came long hours of smoothing the holes inside with a rat tale rasp (the coarsest and longest I could find) until I could insert the tang freely.
Few Words on Planning and Planes
I am sure that as lovers of sharp metal we all understand the importance of a sharp plane blade.
However, it is also critical to have a well fettled (tuned) plane in general. The most critical point in my mind is the sole flatness. A properly tuned plane will be able to take .0005” shavings though if you only manage to go down to 0.001” that’s fine. I definitely recommend taking shaving no larger then 0.001” when working on the handle.
You can do without a plane altogether and use a coarse sand paper bonded to anything flat instead but the result are not the same – the flat sides will be somewhat rounded, parallel sides will not be really parallel etc.
Planning direction is important in nearly all timber species. Exotic timbers such as Cocobolo tend to have interlocking grains which means that in some instances neither direction is ‘right’ and whatever you do you end up with ugly tear outs.
The solution is to create a micro bevel on the flat side of the blade at around 25 deg. The pitch angle will be 70deg. ( 45 (the blade angle) + 25 (micro bevel) ) introducing a scraping motion which will normally tackle most difficult grain timber. Of course, the blades included angle will be around 50deg meaning you need to put more effort in planning Terry Gordon’s planes, made with Australian timbers in mind allow you to use the blade bevel up as well as down thus increasing the pitch angle without increasing the blade’s included angle. I have yet to try them myself but heard lots of good things about them.
From Rectangle to Octagon.
If you cut an octagon out of perfect square is very easy to have it equilateral with 8 135deg. Angles.
However, our octagon is cut from a rectangle rather then a square. This means you can have either:
An octagon with 8 x 135deg angles as in See drawing 4B but then the vertical sides (A in the drawing) will be bigger (or smaller) then the horizontal sides. The corner can be made similar to either but not both..
An equilateral octagon as in drawing 4A where 4 angles (B) are larger then 135 deg. and four angles A are smaller then 135deg.
The first version is obviously easier to make and in fact all Japanese handles are made in a similar pattern. The Suisin handles have small corners and can be expressed as A> B > C. The Watanabe has larger corners so B = C, A > B and A > C.
I have made few initial samples similar to that and was not really satisfied. At that time I have not seen a Japanese handle with my own eyes and looking at the pictures on web site I mistakenly thought that they are indeed closer to form 4A.
So, if you are satisfied with form A, your life is going to be rather simple: Run your blank on a router table with a 45deg bevel cutter. Make sure you are cutting the correct size bevel. I would say that as a starting point have your cutter protruding about 5mm from the table surface, 6mm at the most smaller if your handle is smaller then mine. You can always increase it and do a second routing if it is too small.
If you are like me, and want perfectionism you will be opting for the equilateral octagon of drawing 4A, which does look better.
But how do you cut bevel of 40 and 50 degrees (just an example; exact number will vary of course)?
The way I did it is by using a hand plane (I use a 5 ˝ Lie Nielsen for just about anything) and tilting the blade to one side. Taking a few careful shaving from the corners eventually modified the angles. This is very much a trial and error process and as slow as it may sound, I would recommend taking very frequent measurements. I did two shaving per side all around, and then measured each side. This way I could catch up and correct in time any mistake.
It is definitely a long and slow process and recommended for either hopeless perfectionist or plain masochist, two distinct groups I probably belong to myself.
Tapering the Handle.
I have used here a technique called stopped or partial shavings. Have a look at drawing 3. Assuming that your planning direction is from back to front, you take a couple of shaving starting 1” from the front, another couple of shaving 2” from the front etc, ending with a couple of through shaving to smooth it all out. Repeat for each the 8 sides and measure. Do it enough and you have got your tapering. Again, constant measuring will ensure you do not overdo one side.
If your planning direction is from front to end you will have to start at the front and lift the plane, while still moving forward in order to create the partial shave. It is critical not to stop the forward movement too early. This will take some practice so unless you are familiar with the technique I’d recommend practising on some off-cuts.
Finishing:
I have used the standard sandpaper and then micro-mesh all the way up to 12,000 (~= 4000 in sand paper grit). I have mentioned micromesh in the past so suffice to say that the result I get from using it is a highly polished wood.
Fish has recommended using Pumice, Rottenstone, Tripoli and White Diamond. I have ordered that stuff but would recommend asking Fish (on KF) how to use them since I do not know myself.
Coming next: Glue-up
http://i2.photobucket.com/albums/y36/carbonrider/knifehandle1.jpg
http://i2.photobucket.com/albums/y36/carbonrider/knifehandle3.jpg
http://i2.photobucket.com/albums/y36/carbonrider/knifehandle2.jpg