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| The Care and Use of Natural Water Stones |
posted on 11:00am by David |
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A guide to tool sharpening and stone preparation and maintenance.
Introduction
Sharpening stone material has been mined in Japan for nearly 2000 years. About 1200 years ago, the best deposits were discovered in the mountainous Narutaki District north of present day Kyoto. Over the centuries, the easily obtainable deposits have been mined out. Today, laborious tunneling and mining techniques are required to obtain natural sharpening stones. All of the natural stones sold by the Japan Woodworker have been selected following a centuries old grading Particular care is taken to ensure we obtain stones of a more uniform size and quality than those generally available in Japan.
Basically, there are three categories of natural stones: Coarse stones for initial sharpening, medium stones for removal of the scratches left by the coarse stone, and finish (polishing) stones for final polishing to a razor edge. However, within each category there are numerous gradations and quality levels. Generally speaking, the coarse stones are in great supply and are inexpensive. The medium type stones are slightly more expensive. The finish stones, on the other hand, range from prices of $30.00 to over$2000.00 for the finest polishing stones used for sword polishing. Much of the lore surrounding natural stones is a result of their association with the polishing of Samurai swords. All of our natural finish stones (Awaseto) will give a better finish than any artificial stone.
Awaseto do not produce a mirror bright finish as do the synthetic stones. Japanese craftsmen believe the mirror finish obscures the surface of the bevel and does not allow as fine a determination of its flatness and sharpness. In addition, the Awaseto brings out all of the beauty of the lamination lines in the soft metal (Jigane) of the better quality plane irons much as the temper line in the Samurai sword is brought out by polishing. In practical terms, the actual difference in sharpness and longevity of the edge of tools sharpened by Awaseto and by synthetic stones.
Preparing Natural Stones for Use
Before initial use, the sides and bottom of all natural stones should be painted with several coats of weather resistant lacquer or varnish. It should be noted that natural stones are a result of millions of years of geologic action, and for this reason, no two stones are exactly the same. Natural stones may contain hidden faults or spots which may not be as fine as the rest of the stone. In this case, use a nail to scrap the spot or line slightly below the surface of the stone.
As you become familiar with your Awaseto, you may discover two or three different honing actions related to specific areas on the stones. This is typical of even the most expensive stones. In fact, you may discover you prefer to hone one tool on a certain area of the stone and another tool on yet another area.
Natural stones should only be lubricated with water! Oil or other mineral spirits will destroy the sharpening ability of the stone. Natural stones should not be left immersed in water for long periods of time as this could cause fracturing along naturally occurring fault lines in the stones. I place my natural stones into the water bucket at the same time I begin sharpening with the coarse stone. By the time the wire edge has been obtained, the Ao and Awaseto will have absorbed sufficient water to hone effectively.
How to Flatten Your Stones
Before initial use, all stones should be flattened after soaking for a short period of time in the water bucket. The Aoto can be flattened on #220 grit wet/dry sandpaper. The Awaseto can be flattened on a coarse stone which has been previously flattened. Be sure to place a narrow bevel (approximately 1/32" to 1/16" wide) on all edges of your stones by rubbing the edge on the wet/dry sandpaper at a 45° bevel angle. The reason the edges are beveled is to prevent pressure flaking,which can chip off flakes of material from the sides of the stone.
The Mountain Blue Stone (Aoto)
The Aoto is a unique stone in that it is found only on one mountain in Japan. The temple known as Dai Nichi Do controls the rights to all of the Aoto. These stones are difficult to come by as the villagers in the area are quite content with the income from their farming activities and have little incentive to undertake the demanding and dangerous task of mining for Aoto.
Once you have obtained a "burr" or wire edge on your coarse stone, it is time to move to the Mountain Blue Stone (Aoto). Honing the tool on a Aoto is the next and most important step as this removes the scratches left from coarser stones. The Aoto will rapidly remove the scratches left by a #1000 stone. Follow the same sharpening procedure for the Aoto as was used with the coarse stone.
Nagura Stones
The incredible polishing action of a finish stones results from the mud" which builds up on the surface of the stone during honing. Nagura Stones create this "mud" before honing begins, thus speeding up the polishing process. In addition, the Nagura Stone makes the stone surface slippier, keeping the tool from sticking. Nagura Stones are small pieces of very fine chalky natural stone, specially mined for this purpose.
A Nagura Stone is easy to use. Simply rub it in a circular motion on the full surface of a finish stone until a paste or "mud" develops. If the stone surface is too dry the Nagura Stone will stick To alleviate this problem, add a few drops of water. Generally speaking, the more paste, the better the honing action.
Final Steps
After the scratches have been removed by the Aoto, the final step is to hone the edge on the Awaseto until the wire edge disappears and the bevel is well polished. The most effective polishing action is obtained by first rubbing a Nagura stone over the surface of the Awaseto.
After use, natural stones should be placed on a rack out of the wind and sun and allowed to thoroughly dry out before being stored. With careful used, the more expensive Awaseto will last several life times.
Waterstone Base
Below is a drawing of a Japanese style base which is used to hold waterstones steady during sharpening. The base is easy to make, and the user can vary the design to suit his taste. Redwood or cedar is typically used. However, any water and warp resistant woods are suitable material.
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| Lie-Nielsen Bench Planes: Instructions, Care and Maintenance |
posted on 5:48pm by David |
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A guide to setting up, sharpening and using Lie Nielsen Bench Planes.
Geometry: All Bench Plane blades are bedded at 45° with the bevel down, making the included angle of cut 45°.
Blade Sharpening: Your Lie-Nielsen Bench Plane is ready to cut wood out of the box. The blade is ground sharp at a 25° bevel. You may wish to give it a light honing before use. We recommend water stones used with a honing guide to provide good control. A secondary bevel helps achieve a razor edge. Lightly rounding the corners will prevent them marking your work.
After hardening and tempering, the blades are surface ground on the top and bottom to ensure flatness. This type of grinding produces a very smooth finish that needs little honing to produce a mirror surface.
To advance the blade, turn the adjuster screw clockwise. It is always a good idea to finish adjusting the blade by a forward adjustment to take up backlash and prevent the blade from moving. In order to be able to adjust the blade easily, do not over-tighten the lever cap screw.
A light oiling on the threaded rod and Brass adjuster and the lateral adjustment lever will keep them moving freely. Many people like the patina that Bronze gets with age and use, but if you wish to keep the finish bright a little brass polish is in order. Cherry knob and handle are finished with wiping varnish and should require no maintenance.
We recommend that you carefully dry any blade and apply a light coating of Camellia oil. If you have any questions or problems regarding sharpening, please feel free to contact us.
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| A Guide to Coglow Skew Gouges |
posted on 11:28am by David |
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A guide to selecting, using, sharpening and honing Coglow Skew Gouges.
Introduction
Woodcarving is a traditional art and craft which has seen a considerable body of fine work produced with instruments which have changed little over the past three centuries, and in many cases, over the past millennium. If those implements proved adequate for so long, it seems at the very least redundant and quite probably audacious to introduce new concepts and striking alterations to those customary tools.
I am inclined to think otherwise. The only given is that the improvements must be genuine and the article of highest quality. A number of events in my own carving career led to the conviction that chisel modification could improve performance in a variety of situations without decreasing their utility in others. To begin with, there were the periodic instances when my traditional tools. some 400 in number, were not entirely adequate to the demands. Another consideration was the simple observation that certain tool bends were much more functional suited to the dynamics of human physiology than others, which led to the belief that most might be further improved. To this was added the premise that, if the skewed angle of the guillotine decreased resistance and improved efficacy, the same might be accomplished for a gouge by skewing the blade. Knowledge of the workings of a properly sharpened venier (Figure 1) blade made it equally apparent that a skewed gouge would possess advantages in carving against the grain.
The properly sharpened veiner has extended wings and a recessed trough, making it possible for the wing which it fighting the grain to sever the opposing fibers in advance of the trough. It logically followed that a skewed gouge could present a more radically extended wing than a veiner and allow it to cut smoothly while working in an even more pronounced opposition to the grain. This would alleviate much of the need to change direction of attack and the concomitant necessity of the carver to reposition either or both himself and the work progress. Furthermore, skewing of the gouges would impart this same advantage of properly sharpened veiners to the shallower gouges with their lesser sweeps.
FIGURE 1 - A Veiner properly sharpened, showing recessed trough.
General Characteristics
1. Ergonomically Designed. Each of these tools is designed to present the cutting edge to a particular set of contours in such a fashion as to be conducive to a smooth and effective economy of motion. The act of paring with a chisel is not dissimilar from the use of a bat or club in sports, where much of the satisfaction and success is dependent upon the proper motion of presentation and follow-through.
2. Natural or Positive Rotation (Figure 2). Many carvers apply a slight lateral rotation in using their gouges to produce a smoother cutting action. While the skew motion to the gouges accomplishes this same purpose of itself, it also lends to a rotational proclivity which enhances as the sweep to the gouge increases. While the practice is generally to apply the minimal effort required to control or reverse the natural rotation, there are times when the natural rotation is encouraged or exaggerated for its particular cutting action or simply to extricate a gouge from an excessive bite without stopping the cut and retreating.
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FIGURE 2 - Positive rotation; as the skew is pushed forward it will tend to rotate in the direction of the point. clockwise In this case. This tendency can be exaggerated for a smooth combination cutting action, stopped or reversed or the situation demand. |
3. Lateral Cuts/Reverse Rotation. (Figure 3) Any shallow gouge can be forced sideways. but its blade requires that both forward and lateral pressure be applied. A skew-gouge, by virtue of the extended wing. presents a cutting edge which works with only laterally applied pressure. This works to the carver's advantage in a number of situations. especially in coping with the demands of the rapidly reversing fiber direction in complex grain patterns and the "rolling-over" of certain contours.
With the greater sweeps, this lateral motion in the direction of the skew's heel becomes reverse rotation, and works well to sever an accumulation of fibers at the base of a protected area to leave the skew-gouge's cut with a squared or gently rounded terminus (depending on shank adjustments during rotation), or to facilitate smooth cutting action when cutting diagonally against the grain.
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FIGURE 3 - Any shallow gouge can be forced sideways, but with a skew-gouge the effort is much easier. This expanded range of motion can at times be used to allow a substantial cut near a fragile extension without breaking it, to permit a particular texturing motion. or simply to use the most economical motion for a desired task. Its chief advantage, however, is often that it expedites work in irregular grain with the increased ease of shifting direction of cut. |
4. The advantages of a properly sharpened veiner gouge without the principle disadvantage as designed, the wing of the skew allows the carver to work in opposition to the grain as one might with a veiner gouge. A properly sharpened veiner gouge. however. suffers from the problem that one wing can be doing damage while the other is making the desired cut or its cut may have to be stopped short in order to prevent both wings from damaging a protected area rising from the far side of a recess. Here again. the control and reverse rotational abilities of the skew-gouge allows a finished cut without causing harm to the protected areas. (It should be noted that a cut in opposition to the grain will not always be a finished cut. Depending on the wood, the angle of attack and the set of the skew, there may be some tearing where the opposing grain meets the "valley".
5. Skew-gouges decrease the wood's resistance. More precisely. they take advantage of Its physical properties Most carvers realize that. when working the face grain, the path of least resistance is to cut across the grain, severing both "anchoring" ends of individual fibers simultaneously. With the right and left skew, the opportunities for so working are significantly increased. and logically dictates as a rule of thumb that one employs that skew-gouge which presents its blade more parallel to the fiber direction.
Exception to the rule is the instance in which only one end of the fibers need severing, in which case large amounts of stock can rapidly be removed by presenting the skewed gouge perpendicular to fiber direction and employing only the heel, causing stock to split away as the fiber "anchors" are severed.
6. The pointed blade is often convenient of itself. It allows certain knifing actions and has greater accessibility to those sharp recesses, yet can duplicate the same cuts as a standard gouge.
7. Extra Length. A number of these tools have extended shanks which are fairly heavy. Their purpose is to provide increased accessibility and extra grip, hence control, for the guiding hand.
The Individual Tools
For the sake of brevity, I will resist the urge to expound on specific applications of the individual tools, save the one which is not a gouge. i.e., the bent or incising skews. These odd looking instruments are generally used for a variety of kniving actions. They are superior to a knife in establishing Incisions, especially when the cut is not quite parallel to the line of the fiber. In such cases, a knife is prone to catch in the grain and wander, but the bent skew is adroitly held in complete control, whether pushing and incising with the heel or pulling and cutting with the point. It also works exceptionally well in detailing and cleaning along sharp demarcations such as the edge of a seam.
It can be used gliding on its "elbow" to establish sharp V-cuts in end-grain, but more often the elbow is used as a fulcrum, and a very effective one, against the fingers in a knifing or whittling action. The advantage here Is not only power, but considerably greater control and accessibility. It is a tool which I have come to use extensively.
As to the other tools. their specific applications are numerous and varied. Logic and experimentation should readily reveal their individual talents, providing they are properly sharpened and that can not be stressed too much.
Comments:
A singular advantage to these tools when used for rough-out is that they can easily and cleanly remove the accumulation of chaff at the bottom of a recess or base of a protected area simply by raising the shaft and applying reverse rotation. The same can be done with some standard short-bent gouges, but it is more deftly accomplished with the skews.
FIGURE 4 - The profile of a back-bent skew gouge (solid line) versus that of a standard back-bent "X" indicates the greater clearance which translates to greater versatility and comfort. Ability to cut on the face side is the same, save that the skew has a lesser resistance. |
The Back Bents:
These were designed to facilitate the execution of folds. particularly as they wrap about a convex form and frequently call for working in acute opposition to the grain. They are also proficient rough-out, profiling, and end-grain tools.
Beyond its skew, the advantage of this back bent over the conventional models is that it does not have an elbow to limit the size and shape of contours it can handle, and that, in paring situations, it allows extra clearance for the fingers of the hand gripping the shank (see Figure 4).
Sharpening
As with any chisel, proper sharpening is of utmost importance. The recommended degree of skew ranges from 17.5° for the spoon models to 22.5° for most back-bents to 27.5° for the #4 sweeps. It is important to note that the skew angle for the back-bents should be examined from a point perpendicular to the plane of the top of the blade at its end (see Figure 5), rather than from a point perpendicular to the shaft, and also from the profile of the wing. A skew may be seen from other perspectives. but it will not necessarily be a functional skew. A slightly rounded bevel is recommended. with just a hint of a bevel applied to the inside edge, so that the bevel at the cutting point is 20°-25° and quickly works down to 15°-17°. There should be no abrupt heel to the bevel; rather the bevel should merge with the contour of the bend. beyond that, users are advised to round any face of the tool which will not have an eventual bearing on the blade. This is simply a precaution to reduce marring caused by the back or shank of the chisel.
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FIGURE 5 - When examining the back-bent skew-gouges for the proper skew, they should be viewed from above at a point perpendicular to the blade and double checked from the profile on the point side. Note: because of the curvature of the sweep, the profile skew will not be as great as the skew viewed from the top. Both may be set to individual preference. |
Note:
The majority of the skew-gouges' work should be done with the trough and heel of the blade. The point can be buried so long as the carver is careful to continue with a cutting rather than a prying action. I have yet to break a point. but would recommend that users maintain their blades with a slightly greater bevel towards the point while decreasing it towards the heel of the skew.
My paring work exceeds my mallet use by perhaps a 4:1 or greater ratio with these tools as with my other chisels. The skew gouges do work well with a mallet, though the shallower sweeps have a pronounced tendency to wander in the direction of the point. This easily controlled by barely catching the point of the blade in the wood.
We are indebted to Fred Cogelow for the above observations.
All Cogelow gouges are fitted with octagon shaped Beach Wood Handles
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| A Guide to Sharpening & Caring for Japanese Chisels |
posted on 11:03am by David |
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How to break-in and care for your Japanese chisel.
When a new chisel with a hooped handle is received, quite often the hoop is loose. This is common to all Japanese chisels. The function of the hoop is solely to keep the handle from splitting. Therefore, the hoop should be properly seated prior to use. To do this, first remove the hoop from the handle and place the top portion of the handle on an anvil. With a metal hammer firmly tap all around the top 5/8" of the handle. The idea is to compress the wood so that the hoop can be driven approximately 1/32" to 1/16" below the top of the handle. After several days, the wood will swell and bind the hoop firmly to the handle. I like to speed this up by soaking the handle over-night in a light bodied tung oil based finish such as Sealacell.
Many woodworkers are initially concerned that the flat area directly behind the cutting edge will be eliminated with repeated sharpening thus rendering the chisel useless. However, this will not occur if the following simple sharpening steps are taken.
A new chisel should always be honed prior to use. First, the back of the chisel must be honed on a flat coarse stone (#1200 or #2000 grit stone preferred) until the area directly behind the cutting edge is completely flat across the width of the chisel. To do this, rub the back of the chisel side ways along the length of the stone. The proper technique is to keep the chisel flat on the stone with finger pressure applied directly on the bevel. Keep rubbing until the area directly behind the cutting edge is flat. This will be obvious by inspection. Second, transfer the chisel to a flat #6000 Finishing stone or #8000 Polishing stone and hone as above until a mirror surface is obtained.
Future sharpening will require that the chisel back be honed only on the Finish or Polish stone unless after repeated sharpening the cutting edge reaches the hollow grind. If this happens, it is easily corrected by following the above procedure until about 1/32" of flat area is re-established.
After the back has been honed and polished, the bevel of the chisel is sharpened. This is done by rubbing the bevel on a flat coarse stone until the "burr" is turned up. At this point, transfer the chisel to the finish stone and alternately hone the bevel and back of the chisel until a razor edge is obtained.
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| How to Sharpen Japanese Chisels |
posted on 11:56am by David |
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Instructions for sharpening Japanese Chisels.
Each chisel is inspected prior to shipment to assure that it meets our own rigid standards. While each chisel is ground sharp by the maker, we can not guarantee each edge will be ground perfectly square and free of minor nicks. However, edges of this sort are few and far between.
When a new chisel with a hooped handle is received, quite often the hoop is loose. This is common to all Japanese chisels. The function of the hoop is solely to keep the handle from splitting. Therefore, the hoop should be properly seated prior to use. To do this, first remove the hoop from the handle and place the top portion of the handle on an anvil, With a metal hammer firmly tap all around the top 5/8" of the handle. The idea is to compress the wood so that the hoop can be driven approximately 1/32" to 1/16" below the top of the handle. Then place the handle in a container of a oil base sealer (I prefer to use tung oil based products) and allow to stand overnight. This will cause the handle to swell lock the hoop in place.
Many woodworkers are initially concerned that the flat area directly behind the cutting edge will be eliminated with repeated sharpening thus rendering the chisel useless. However, this will not occur if the following simple sharpening steps are taken.
It is best practice to hone a new chisel prior to use. First, hone the back of the blade on a flat coarse stone (#1000-#1200 grit water stone preferred) until the area directly behind the cutting edge is completely flat across the width of the chisel. To do this, rub the back of the chisel side ways along the length of the stone. The proper technique is to keep the chisel flat on the stone with finger pressure applied directly on the bevel. Keep rubbing until the area directly behind the cutting edge is flat. This will be obvious by inspection. Second, transfer the chisel to a flat #6000 to #12000 grit finish stone and hone as above until a mirror surface is obtained.
Future sharpening will require that the chisel back be honed only on the Finish stone until after repeated sharpening the cutting edge reaches the hollow grind. When this happens, it is easily corrected by following the above procedure until about 1/32" of flat area is reestablished.
After the back has been honed and polished, the bevel of the chisel is sharpened. This is done by rubbing the bevel on a flat coarse stone until the "burr" is formed. At this point, transfer the chisel to the finish stone and alternately hone the bevel and back of the chisel until a razor edge is obtained.
Should the you have any difficulty with the above or any other aspect of sharpening or caring for Japanese chisels, please feel free to contact us.
Copyright ©2005 Japan Woodworker
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| The Care and Use of Synthetic Waterstones |
posted on 6:04pm by David |
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A guide to tool sharpening and stone preparation and maintenance.
Introduction
A number of Japanese firms manufacture synthetic water stones. After many years of experience, we have discovered those brands which offer the most consistency in quality, cutting effect, and value to the user. Generally speaking, synthetic water stones can be classified into three groups: Very coarse stones for the maximum removal of metal, medium coarse stones for refining the edge and establishing the "burr", and finish stones for final honing and polishing of the edge. Very coarse stones are available in #80 to #400 grits. Medium coarse stones are available in #700, #800, #1000, #1200, #1500 and #2000 grits. Finish stones are available in #3000, #4000, #5000, #6000 grits. Polish stones are available in #7000, #8000 and 12000 grits. And Shapton makes a #30000 grit super polishing stone.
In addition to different grit sizes, we offer stones in a variety of abrasive materials and manufacturing methods. Generally speaking, the more expensive the stone, the faster it will cut per grit size and the longer it will last. The abrasive types are aluminum oxide, silicon carbide and chromium oxide. All of the stones, except for the Debado series are heated at high temperature to fuse together the abrasive particles in a porous matrix. The Debado Stones are chemically cured in a precisely temperature controlled humid environment.
A typical sharpening sequence is to first establish a flat bevel and remove any nicks with one of the very coarse or medium coarse stones. The choice of grit depends basically upon how much material needs to be removed from the bevel in order to leave a clean, true edge. If there are no nicks or other defects, the #1200 or perhaps #2000 grit stone is the best choice. However, if more metal needs to be removed the #700, #800 or #1000 grit stones cut faster. This of course means less effort will be required.
The #80 through #400 grit stones are the best choice when a considerable amount of metal must be removed. Keep in mind though; these stones will leave scratches which must be removed with a medium coarse stone prior to final polishing.
After the medium coarse sharpening is completed and a "burr" is obtained, the tool is transferred to a finish stone and alternately honed on back and bevel sides until the "burr" is totally removed. Finishing or polishing can be accomplished in one step, with any stone from #3000 grit to #8000 grit. However, in general, a better edge will be obtained if the tool is first honed on a #3000 or #4000 grit stone prior to final polishing on #6000, #7000 or #8000, 12000 grit stone.
Debado Stones
As noted above, the Debado Stones are manufactured by a different process and do not require soaking in water prior to use. You need only apply a handful of water to the stone surface to begin sharpening. Please be aware that these stones will deteriorate if left in water. As with natural stones, the Debado Stone may occasionally develop small fissures. These fissures are normal and do not affect the sharpening qualities or cause any deterioration of the stone.
Shapton
Shapton Water Stones are color coated to enable the user to avoid mixing up grit sizes and do not need to be soaked prior to use. Simply splash a handful of water on the stone's surface and start sharpening. Shapton stones should be stored dry. If left in water they will begin to deteriorate over time. Otherwise use as described below.
Preparing Stones for Use
Except for the Debado Stones, all of our synthetic water-stones must be soaked in water for several minutes prior to use.
You will see the bubbles rise to the surface as the stones absorb water. The very coarse and medium coarse stones, except for the Debado Stones can be left permanently in water without damage to the stones. However it is always best practice to remove finish stones from the water after use. Under no circumstances should any oil based lubricant be used, as this will ruin the stone. A few drops of Charlie's Soap added to the water will help improve the cutting effect of the stone.
It is very important when sharpening chisels and plane irons that your stones be flat. Checking for flatness is particularly important, since any irregularity in the surface of the stone will be transferred to the tool's edge. After a bit of experience, you will be able to tell by visual inspection whether or not the stones are flat, or you may use a straightedge for this purpose.
How to Flatten Your Stones
The easiest method to flatten a coarse stone is to rub it across wet/dry sandpaper placed on a flat surface. If your stone is fairly flat, #220 grit paper is sufficient. However, if a greater amount of material needs to be removed, then a coarser paper such as #120 grit is appropriate. The finish stones are easily flattened by rubbing them together with a previously flattened coarse stone. At this time, it is a good idea to sand a 45° bevel on the 4 top edges of the stone. This prevents "pressure flaking" of chips from the sides of the stones.
How to Sharpen
Now that your stones are saturated with water and flat, you are ready to begin sharpening. Place a coarse stone on a flat, secure surface so that it will not shift during use. Begin rubbing the tool back and forth on the stone. Allow the "mud" to build up and remain on the surface. This will give a better sharpening effect and ultimately, a keener edge. Should the stone's surface begin to dry out during sharpening, add a finger-tip or two of water to the surface. As soon as a wire edge or "burr" is obtained, transfer to a finish stone and complete honing of bevel and back side of the blade. Proceed on the finish stone as already described for the coarse stone.
If the tool requires a considerable amount of sharpening, periodically check to ensure that the stone's surface is flat. If not, flatten as previously described.
Blue Stones (Ao Toishi)
For the finest edge, it is suggested a Blue Stone "Ao Toishi" be used between the coarse stone and the finish stone. There are now two types of Ao Toishi: the original "mountain blue" natural stone and the new "Nonpareil" synthetic stone. Blue Stones are used to remove the scratches left by the coarse stones. This improves the polishing action of the finish stone, giving a sharper, longer lasting edge. In addition, Blue Stones can be used to touch up an already keen edge (by Western standards) before re-polishing on the finish stone.
Nagura Stones
The incredible polishing action of a finish stones results from the 'mud" which builds up on the surface of the stone during honing. Nagura Stones create this mud before honing begins, thus speeding up the polishing process. In addition, the Nagura Stone makes the stone surface slipper, keeping the tool from sticking. Nagura Stones are small pieces of very fine natural stone, specially mined for this purpose. Now a day, manufactured Nagura stones are available.
A Nagura Stone is easy to use. Simply rub it in a circular motion on the full surface of a finish stone until a paste develops. If the stone surface is too dry the Nagura Stone will stick. To alleviate this problem, add a few drops of water. Generally speaking, the more paste, the better the honing action.
Water Stone Base
Below is a drawing of a Japanese style base which is used to hold water stones steady during sharpening. The base is easy to make, and the user can vary the design to suit his taste. Redwood or cedar is typically used. However, any water and warp resistant woods are suitable material.
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| How to Care for and Sharpen Double Bevel Kitchen Knives |
posted on 11:46am by David |
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Instructions for obtaining a razor edge on any double beveled kitchen knife.
Introduction
Please note that all Japanese kitchen knives sold by us come with a keen well sharpened edge. They should be handled carefully to avoid cutting yourself, as well as to protect the edge. If a bit of care is exercised, the need for re-sharpening will be greatly reduced.
Our kitchen knives are high quality tools and should only be used for cutting food items. Bone and shells should be avoided. If you intend to cut relatively hard foods such as winter squash, please re-sharpen the blade in the following manner. Hold the blade at approximately 22½° to the surface of a finish stone and hone the edge for 10 to 12 strokes. Turn the blade over and hone the other side in the same manner. Finally, strop the edge thoroughly using aluminum oxide abrasive.
Always use a cutting board to protect the edge. Never cut on crockery, Formica countertops, sinks, etc as this will chip the edge of your blade.
After use, clean the knife thoroughly, rinse in warm water and dry well. Apply a bit of vegetable or camellia oil to the blade and store in a dry place, well away from children. Store the knife in such a way that the edge does not come into contact with other cutlery or utensils. Under no circumstances should any of our knives be sent through the dishwasher.
In Japan, it is traditional to attach the handle without pinning it permanently to the blade. We recommend that handles of this type be well saturated with an oil finish. This can easily be done by standing the knife, handle down, into the can of finish for about 20 minutes. Use a soft cloth to wipe off any excess oil from the handle and blade. Allow to dry overnight and apply a second coat of oil. Non-toxic Sealacell finish (our #37.119 for a pint) is recommended.
Since unpinned handles are not permanently attached to the blade, they can occasionally become loose. If this happens, remove the handle and mix a small amount of 5-Minute epoxy resin. Fill the opening in the handle with the epoxy and reinsert the blade. Remove any excess epoxy, and allow to harden for a few minutes. This procedure will permanently install the handle on to the blade.
How to Sharpen
When a blade becomes too dull to cut well, it is time to re-sharpen. The first procedure is to check the edge for nicks. If there are any, rub the edge on a coarse water stone (#600 to #1000 grit) until the nicks are removed. Now hold the blade held at approximately 11¼° to the surface of the stone, and rub the blade up and down the length of the stone while at the same time sliding it across the stone. When a "burr" or wire edge is felt, turn the blade over and continue sharpening at 11¼°. This creates an initial bevel on the edge with an included angle of approximately 22½°.
Now transfer to a #4,000 to #6,000 grit water stone, and sharpen as described above with the blade held at approximately 22½° to the surface of the stone. After 8 to 10 strokes, turn the blade over and hone at 22½° for another 8 to 10 strokes. This will create a "micro-bevel" with an included angle of approximately 45°.
Finally, strop the edge using aluminum oxide powder. Hold the blade at 24° to 25° to the strop and strop each side. stropping once a week will double the longevity of the edge.
Supplies
If not obtainable locally, Camellia oil, nontoxic natural finishes, strop, abrasives and sharpening stones can be obtained from the Japan Woodworker. The Japan Woodworker has the largest selection of water stones available to suit any sharpening situation. If you are undecided as to which stones to select, please feel free to call for our recommendation.
Ceramic Knives
Ceramic blades are easy to care for. They do not require any special oil or treatment, other than rinsing in hot water. As long as they are restrained and not allowed to rattle around, they are dishwasher safe. The blades do not need to be thoroughly dried before storage.
Since the blades are very fine grain, they are can be chipped if hit against a hard object, i.e. silverware, tableware etc. So in this respect they are similar to our high quality metal blades. If the blade is chipped, it can be repaired using #600 and #1200 grit diamond stones. The DMT SuperHone Kit is recommended for this purpose.
Sharpening Service
If you prefer, the Japan Woodworker will properly restore, hand sharpen and return any of the double bevel blades we sell for a $5.00 fee (which is for return shipping). We will also sharpen knives from other sources for $1.00 per inch of blade length ($4.00 minimum) plus return shipping charges. All knives should be returned to us with a check in the correct amount or with your credit card number. Your knife will be sharpened and returned via UPS within fourteen (14) days.
If additional information is required, please feel free to contact us.
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| The Care and Sharpening of Single Bevel Japanese Kitchen Knives |
posted on 11:41am by David |
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Special sharpening techniques for Japanese kitchen knives. (Hocho)
Introduction
Thank you for purchasing one of our fine quality, single bevel Japanese kitchen knives. The Kanji characters for Hocho are a synonym for "symbol of wealth". The Hocho is an important part of Japanese culture and is highly valued as a gift item for weddings and other important social events.
All of our Hocho are hand-forged by master knife makers. Special, expensive forging techniques known as "Hon Kasumi" and "Hon Yaki" ensure our Hocho will take and hold an edge impossible to obtain with any Western made knife. With care in handling and sharpening, the cutting qualities of your Hocho will continue to improve over the years.
A well sharpened edge is a delicate thing. Always use a cutting board. (We prefer soft plastic types, as they are considerably more hygienic and easier on the edge than are wooden boards.) Be sure never to strike the edge against a hard surface such as counter tops, metal objects or glassware, etc. Never use the blade as a pry bar or can opener and refrain from sending your knife through the dishwasher.
The Sashimi and Usuba shapes should never be used to cut bones or vegetables with a hard rind such as winter squash. They should only be used for slicing, never for cleaving.
The Deba shape can be used to cut uncooked chicken and fish bones. The proper way to cut bone is to place the knife on the spot where the cut is to be made and then strike the top edge of the blade with the palm of the left hand, while at the same time applying downward pressure on the handle with the right hand.
After use, always rinse the blade in warm water and wipe dry. Apply a bit of camellia oil to the blade and store in a dry, well protected place. A wooden sheath is well worth the investment to protect the edge during storage. Wooden sheaths are relatively easy to build and make an interesting afternoon's project.
Initial Care
While all of our new Hocho are ready for use, the following two steps will enhance its beauty and increase its longevity. First, soak the handle for twenty minutes in a tung oil finish. (Non-toxic Sealacell Oil Finish is highly recommended.) Be sure to totally submerge the handle. Remove the handle from the finish and completely wipe dry with a soft cloth. Allow the handle to dry overnight before subjecting it to water. The second step is performed over a period of 30 days. Each day rub down the blade with a bit of scouring powder such as that used to clean the bottom of copper pots. Be sure to keep your fingers well clear of the edge. This procedure refines and polishes the surface of the blade. A well polished blade is much less likely to develop tarnish or rust.
Sharpening
Sharpening a single bevel Hocho is relatively easy. The first step is to obtain several water stones, a coarse #1000 grit stone and a fine #4000 or #6000 grit stone. After submerging the #1000 grit stone in a container of water for several minutes, flatten it by rubbing back and forth on a sheet of #220 grit wet/dry sandpaper placed on a flat surface such as a counter top. It will be obvious by inspection when the stone surface is flat.
Next, place the blade with hollow side flat on the #1000 grit stone. The blade should be held at an angle of about 30 degrees to the length of the stone. Now rub the blade back and forth on the stone, while at the same time moving the blade across the width of the stone. With long blades, it will be necessary to sharpen the blade a section at a time. Be sure to overlap each section. Continue in this manner until the entire blade as been rubbed on the stone. Occasionally inspect the blade to be sure all parts along the edge are being flattened. PLEASE NOTE: It is only necessary to have a very small area (about 1/32") directly behind the edge flattened. Continue rubbing on the #1000 grit stone until this area behind the edge is flattened along the full length of the blade.
Now turn the blade over and sharpen the bevel side. Hold the blade at an angle of about 30 degrees to the length of the stone. Rub up and down the stone while at the same time moving the blade across the width of the stone. As above with long blades, it will be necessary to sharpen a section at a time. Be sure to keep the bevel flat on the stone while sharpening. Continue in this manner until a wire edge is detected along the full length of the blade.
Now transfer the blade to the fine grit stone, and alternately rub back and bevel sides as described above until both are well polished and the wire edge is removed. Finally, tip the bevel side up approximately 5 degrees and hone for six or seven strokes on the bevel side. Reverse the blade and again hone the back side flat on the stone for an equal number of strokes. This step creates a micro-bevel which toughens the edge without harming its cutting effect.
The life of the edge can be considerably extended between sharpenings by stropping once a week with a fine aluminum oxide abrasive. Always strop the bevel side of the blade at the angle of the micro-bevel. This is typically about 5 degrees. Be sure to keep the back side of the blade flat against the strop. When stropping, always draw the blade with the edge trailing. Otherwise, the blade would slice into the strop.
The purchaser should feel free at any time to contact us with any questions regarding the care and use of their Hocho.
Supplies
If not obtainable locally, Camilia oil, Sealacell non-toxic finishes, Strop and Abrasive can be obtained from The Japan Woodworker. The Japan Woodworker has the largest selection of water stones available to suit any sharpening situation. If you are undecided as to which stones to select, please feel free to call us for our recommendation.
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| How to Condition Japanese Planes |
posted on 3:32pm by David |
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A guide for setting up and adjusting Japanese planes for successful use.
Introduction
The first time user should be aware that Kanna do not arrive from the maker ready for use. All best quality Japanese plane bodies (Dai) are made from select, air-dried Japanese Red Oak (Akagashi) or Japanese White Oak (Shirogashi). When the planes come from Japan to the drier U.S. climate some shrinkage occurs. Actually, shrinkage also occurs in Japan, and the Japanese woodworker expects to adjust or "condition" his plane.
The first step is to flatten the sole. There are several ways to do this. However, the easiest for the first time user is to use sandpaper on a flat surface, such as a table saw top. With the plane iron and chip breaker inserted tightly into the , rub the sole a few times across #220 grit sandpaper placed on the flat surface. Inspect the sole and observe the sanding marks. Take a sharp chisel or plane iron and scrape the areas showing sanding marks. Again, rub on the sandpaper and repeat scraping until the sole is flat. This will be obvious because there will be even sanding marks the length and width of the sole. GO SLOWLY!
An easier way to scrape the sole is to use a Japanese Scraping Plane (Dainaoshi Ganna), our #01.240. The Dainaoshi Ganna is used across the grain of the sole. It is worked from the blade slot to the front of the , and from the blade slot to the back of the . Flatness can be tested either with a straight edge or with sandpaper on a flat surface.
Now remove the iron and chip breaker by striking the back of the Dai with a wood-mallet. Place the plane iron hollow side down on a flat coarse (#1000 or #1200 grit) water stone and hone with even pressure directly above the bevel until the area immediately behind the edge is flat from one side to the other. Now rub on a #6000 or #8000 grit finish stone until well polished. Next hone the bevel side on a coarse water stone until the "wire edge" is obtained. Then alternately hone the hollow and bevel sides on the finish stone until well polished. Use about 5 strokes on the bevel for each stoke on the back.
To fit the chip breaker, place it in position on the iron. Be sure it does not rock on the iron. Any adjustment is made by tapping down one tab (found at the top of the chip breaker) or the other until the chip breaker sits evenly on the iron . Now hone the chip breaker hollow side down on a coarse grit water stone until a flat area is established directly behind the edge. Next polish this area on a finish stone. Turn the chip breaker over and sharpen at an angle of 20° on a coarse water stone until the edge is sharp, then polish the bevel and hollow side on a finish stone. Finally, hold the chip breaker at an 85° angle to the finish stone and make a dozen or so strokes. This will add a secondary or "micro bevel" on the chip breaker. The ideal chip breaker breaks the shaving without offering any further resistance.
Because of the shrinkage of the plane body, initially it is unlikely the plane iron will protrude through the sole.
So, first push the iron into the Dai by hand as far as possible. There should be some sideways (lateral) movement of the iron. If not, remove the iron and with a narrow chisel pare a slight amount from each side of the opening for the iron. This will allow lateral movement for the plane iron and will eliminate the chance of cracking the Dai as the iron is driven in.
Replace the iron and push it by hand into the Dai as far as possible. Inspect the opening at the sole . If the iron is within 1/16" of the opening, it should be possible to tap the top of the iron with a mallet or small hammer until the edge protrudes through the sole. If the edge is greater than 1/16" from the opening, remove the iron and rub a soft lead pencil on the sides and back of the iron. Now push the iron by hand as far as possible into the body.
Remove and carefully pare, scrape or rasp the area of the Dai marked with the pencil lead until it is removed. Replace the iron, and check if it is now within 1/16" of the opening. If not, repeat the above procedure. Normally two or three times will suffice. Check the sole from time to time to ensure it has remained flat.
When the iron is finally fitted and in place, inspect the width of the edge of the iron at the opening. The edge should NOT be wider than the width of the throat. It will generally be necessary to grind or hone away additional material from the corners of the iron's edges. Inspection of the iron will show that the corners have been partially removed by the maker. The user must make final adjustments. If the corners are not fitted, it is possible for a chip to lodge between in the iron and the slot in the Dai. If this happens, the good cutting effect will be lost until the chip is removed.
At this time, check the chip breaker to ensure that it can slide easily into the Dai. If the Dai is two narrow, pare off a bit of the sides so the chip breaker can be easily inserted into place.
This completes adjustment for the small smoothing or polishing planes.
The large planes (60mm and wider) require additional adjustment of the sole. The sole must be slightly (about a hair's width) scraped out between a 1/2" area directly in front of the throat and a 1/2" area at the front end of the Dai. The area behind the throat is scrapped out to the end of the Dai. This is most easily accomplished with the Dainaoshi Ganna. The scrapping motion is across the width of the sole.
To complete adjustment, place a pair of wind sticks on the 1/2" area in front of the throat and the 1/2" area at the front end of the Dai. Check to see if the sticks are parallel. This will ensure the plane makes a true cut. If the sticks are not parallel, scrape sufficient material at the front of the sole until the wind sticks are parallel. Once the wind sticks are parallel, use a straight edge or the sandpaper method to ensure the sole is touching only at the 1/2" area in front of the throat and the 1/2" area at the front of the Dai. If any other area of the Dai is touching, slightly scrape it down. The plane is now conditioned for use.
It is a good idea at this time to seal the Dai. This is easily accomplished by covering the throat opening with masking tape and filling the throat area with a good quality Tung oil finish. We recommend the Sealacell sealer (our part numbers 37.119, pint or #37.122, quart) for this purpose. Set aside until the oil begins to seep from the ends of the Dai. Allow to dry over night and repeat the process.
Additional Information
For additional information, please refer to Fine Woodworking on Planes and Chisels, Japanese Woodworking Tools: Their Tradition, Spirit and Use by Toshio Odate, Shoji, How to Design, Build, and Install Japanese Screens by Jay Van Arsdale and "Fine Woodworking", Vol #75, page 82.
Copyright ©2004
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| How to Sharpen Japanese Woodworking Knives |
posted on 11:36am by David |
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This information applies to all single bevel chisels.
Because most Japanese woodworking knives are ground with a single bevel, they are relatively easy to sharpen. WARNING: under no circumstances should the blade be ground on an un-lubricated grinder. To do so will destroy the temper of the blade.
While oil stones can be used for sharpening Japanese knives, much better results will be obtained using Japanese water lubricated sharpening stones. Generally speaking, Japanese water stones can be divided into two classes: Coarse stones for initial sharpening and Finish stones for final polishing to a razor sharp edge.
First, check to be sure the surface of your sharpening stones are flat. Otherwise, it will be difficult, if not impossible, to obtain a well sharpened edge. If you are using Japanese water stones, please follow our instructions for flattening your water stones.
Now inspect the edge of the blade for any nicks or other defects. If there are any defects, rub the edge of the blade at a 90° angle on a coarse stone until they are completely removed. While doing this, be careful not to change the profile of the edge.
The back of the blade should be sharpened first. To do this, place the blade perpendicular to the length of a coarse stone with finger pressure applied directly on the bevel. Rub the blade back and forth across the stone until the area directly behind the edge is honed the full length of the edge. Be careful not to over-sharpen the back. It is not necessary or desirable to completely fill in the hollowed area. This will be obvious by inspection. Now transfer the blade to a finish stone and hone the back of the blade until a mirror finish is obtained.
To complete the sharpening, rub the bevel across a coarse stone until a burr is obtained along the full length of the edge. The presence of a burr is easily felt by drawing a finger at a 90° angle across the back of the edge of the blade. As soon as the burr is detected, transfer the blade to the finish stone and alternately hone the bevel and back side until the burr disappears. Best practice is to hone at a ratio of five strokes on the bevel for each stroke on the back side.
Should the edge seem somewhat brittle and not hold up well in hardwoods, it may be necessary to add a "micro bevel". This is done after initial polishing by increasing the angle of the bevel to the finish stone about four to five degrees and honing ten to fifteen strokes. A brittle edge in a new tool is usually considered to be a sign of a superior tool. As the tool is sharpened and the surface metal formed at the time of manufacture is removed, tougher, more durable metal underneath is exposed. Additionally, the honing process itself is thought to increase the edge holding properties of the blade.
The tips of Japanese knives are very thin and hard and will occasionally break during use. This is a normal condition, and many Japanese woodworkers regrind the tip even before using the knife. The best way to deal with a broken tip is to turn the knife on its back edge rub at an angle of 60° to 75° on a very coarse stone. Continue in this fashion until the broken portion has been ground away and a sharp point re-established.
Carefully dry the blade and apply a light coating of Camellia oil or mineral oil. If you have any questions or problems regarding sharpening, please feel free to contact us.
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