Sharpen Planes And Chisels Without Going Broke

This article has been sitting on my desk, waiting for pictures, for over two years. I finally got around to taking them but I am not completely satisfied. I needed a helper to take the photos the way I had originally envisioned and I didn't get the rquired assistance, so they didn't turn out as I wanted them to. I have also made a few changes to the shop and some additions to my sharpening center. However, the content is just as fresh.

Since writing this my wife bought me a Tormek but the only real change it has made to my life (other than sharpening every knife and pair of scissors in the house) is that I'm guaranteed never to burn the edge of a blade again. My sharpening procedures really haven't changed. I hope you enjoy the article.

Contents

This is a very lengthy article so I thought I would include links to the various sections so that you can skip ahead when looking for a prticular piece of information.
• Introduction
• Equipment
• Preparing an Edge
• Step One: Jointing
• Step Two: Grinding
• Step Three: Honing to 1000X
• Step Four: Honing to 4000X
• Step Five: Buffing
• Maintaining an Edge
• Parting Thoughts

Introduction    [Contents]

I love sharpening things. You may think it strange and there is probably a host of others who agree with you. Many woodworkers dread sharpening and consider it onerous – a time consuming chore to be put off as long as possible. Only when a chisel is so dull its blunted edge resembles a hammer’s head are they forced to exhume their only oilstone from that seldom explored drawer in which it lies – entombed in a mass of greasy sawdust. I felt that way myself until I realized I had to make peace with necessity of sharpening. Only then could I improve as a woodworker.

Through years of experimentation, reading, and asking questions I have developed a system that produces reliable, repeatable results in a short period of time. It can work for you too. Once you get a feel for the skill, maintaining an edge on your tools takes no time at all – a few minutes a day. Preparing an edge for use takes longer but you only go through that process occasionally. The key is in knowing when it’s necessary to start up the grinder, and when a simple honing will suffice.

These techniques will maintain your chisels and plane blades in perfect working condition. I use a similar approach on my carving gouges and lathe tools but they require the use of a jig or two, a topic for a later date. For now we will stick to straight edge tools, although you can hone your gouges in the same fashion – without the use of jigs. Nevertheless, a certain amount of equipment is required to produce proper, consistent results.

Over the years I have tried oil stones, water stones, the extolled Scary Sharp system (quite popular on the internet), a plethora of different grinding wheels, and - most recently - the Tormek wet grinder. My system is best described as the cheapest I could get away with while still producing sharp tools that slice through hard woods effortlessly. It is really a combination of things I have read and seen in a variety of places. If I had it to do all over again, I would probably start out the same way but I would, and will, eventually migrate to the Tormek system.

After experimenting with the Tormek recently, I have to say that the wet grinder itself, a select few of the jigs they offer, and a 4000X gold stone would sharpen everything you can think of – quickly and with an edge I can’t quite match now. But don’t run out and buy the complete kit with everything in it - many of the attachments are unnecessary.

My system consists of five steps. Before going through each one, I will talk about the equipment that I use and the sharpening station where I use it. Then I will describe the process I use to maintain an edge and how I decide on when it needs to be reground. Maintaining an edge isn't a laborious process and is simply the repetition of some of the five steps until it’s time to start again from the beginning.

Equipment    [Contents]

My sharpening station is set up on a three foot by four foot piece of half inch mahogany plywood. (I told you I wrote this a while ago.) This is clamped to the top of my Black & Decker Workmate and placed against the wall of my shop in an out-of-the-way place. You can read more about that on my Tool Tricks page where I describe it. I bolted a grinder and tool rest to the plywood and, except for the floor lamp devoted to that corner of the shop, that’s my work station.

The centerpiece of my station is a cheap (forty dollar), 6" grinder I picked up at The House of Tools in Edmonton. At that price it obviously isn't a low speed model. (If a low speed grinder is within your budget, buy it instead.) The grinder is bolted to the plywood permanently and is modified by the removal of all of the stock blade guards and tool rests. The safety police will probably hunt me down over the fact that I have removed all of the wheel covers and they spin completely out in the open. Do I grind a hole in my fingers? Yes - occasionally. Its no big thing, but there is a reason for the alterations.

On the right hand spindle I have a fine, white, aluminum oxide wheel that I purchased from Lee Valley. It’s the inexpensive three quarter inch variety (but if you are shopping around, they now have a wheel one inch thick you are better off buying). However, on the left spindle I mount alternately, depending upon the tool I am sharpening, either a 6" by ¾" hard felt wheel (also purchased from Lee Valley) or a 6" by ¾" rag buff. The felt wheel is for all my straight blades and irons and the rag buff is to polish and remove burrs from freshly ground turning tools or to polish honed carving gouges. Because you polish with the rotation of the wheel instead of into the rotation, you need to remove or alter the guards so that you can hold the tool on the bottom of the wheel while it is spinning. You could turn the grinder around or move it away from the wall so you can get behind it but that would increase the time taken to sharpen – something I am not willing to do. Okay safety police, come and get me!

As an aside, I no longer recommend aluminum oxide wheels. They cut much slower so you have to hold the tool on them longer. The cheap, forty grit wheel you got with the grinder is much better. It will cut much faster so if you take light passes it won’t heat up the blade as much.

I buff my edges free hand but in front of the 120X wheel is a Veritas tool rest that assists with grinding. It is absolutely necessary to get an even grind on your tool and a tool rest, or jig of some kind, is the only way I can do it (if you can grind freehand, my hat is off to you). In conjunction with it I use a Veritas blade holder that clamps on to the tool and has a fence that matches the groove on the tool rest. You can go to http://www.leevalley.com and check it out if you like (it has been greatly improved since I bought mine). The part number for the tool rest is 05M23.01 and the part number for the blade holder is 05M06.01. You can even buy them both together and save a few bucks.

In a Rubbermaid container I keep a 250X/1000X combination water stone and a 4000X Japanese gold stone. I also keep a slip stone for honing V-tools and carving gouges. I prefer water stones as they are cleaner and they seem to cut faster, which will reduce your sharpening time. I never use the 250X stone unless I am flattening the back of a new tool. I wouldn't even have it if I hadn’t got an amazing deal on that stone. I picked it up at the Lee Valley store for a fraction of the regular price because one end was broken off. It doesn't affect how the stone works and I have a small piece that I use as a toolbox stone if I am not near the shop and need a quick honing.

In addition to these items, I keep a small container of water and my green honing compound that I use to charge the felt wheel and rag buff. I have a small plastic tray I made in grade 8 Industrial Arts that I use to hold the honing compound in and it also serves as a pond of water for cooling freshly ground blades.

Preparing an Edge    [Contents]

The edge of every tool in my shop goes through two treatments: preparation and maintenance. I use five steps I use to prepare any chisel or plane iron. Maintaining an edge is much the same, only less work. In fact it is probably harder to know when to redo the edge than it is to touch it up. That’s how simple maintaining an edge is, but don’t worry. I have a sure-fire way to tell when you need to go back to the grinder too.

Step One: Jointing    [Contents]

Jointing an edge is essential before you can sharpen the tool but, much of the time, you can skip right over this step and go on. Don’t skip the jointing if you have any big nicks on the edge, or the edge is out of square. If the nick is really small it will probably grind out in the next step so you don’t need to go through this process. If you are in doubt, or the nick is easily visible from the back of the blade, you should joint the edge.

Like jointing a board, jointing an edge means to make it flat and square. Take the truest try square you have and hold its fence against the side of the blade. Then, slide the square down so it nearly touches the blade's edge. Holding it up to the light should give you a good idea of how out of square the edge is. If you see an even amount of light peeking through along the entire edge you are fine; if not, you will need to joint it. Even if an edge looks square to the side of the tool, it can be rough or wavy. This can be caused by almost anything from being dropped to poor machining at the factory. You want the edge to be perfectly straight and flat, and perfectly square to the edge of the blade. But why is this important?

The quick answer is that your joinery will be better. It also makes the tool easier to grind as you can register the edge against the marks found on most grinding jigs so that you only need to touch up the tool rather than grind a whole new edge. When chopping out dovetails, you get better results if you hold the chisel straight instead of askew, compensating for an angled edge. And you need a square, straight edge to chop accurately to your scribe lines. On a plane, the lateral adjustment lever only goes so far and then you run out of room for adjustment and may encounter problems. There is nothing I hate more than planing a board flat only to find ridges because the blade was out of square.

Once you have determined the need to joint the edge, it is a simple process. I like to paint the edge with machinist's bluing, or layout fluid. (You can get by with a magic marker but the edge will not be easily seen, as it is with the layout fluid.) Once painted, take a square and hold the fence to the side of the blade, with the edge of the square as close to the edge of the tool as you can. You don’t want to grind off too much. Using a sharp, and I mean freshly sharpened, scratch awl, scribe a line across the edge of the tool. If you painted it with machinist's fluid first you will see why I like it. The freshly scratched metal shines forth and gives you no doubt as to where to grind to.

Place the tool in the grinding jig with your scratch mark up and make sure it is perfectly square to the jig before you tighten it down. Set the jig on the tool rest and adjust the rest until the blade is perpendicular to the edge of the wheel. Then grind a little at a time until you have taken the edge down to the scribed line. The freshly ground blade will provide you with a straight, square foundation on which to build an edge, and don’t worry if it looks like you ruined the tool. We’ll fix that in a moment, but first I should make a few suggestions about grinding before proceeding to the next step.

A grinding wheel at high speed will make a meal out of your tool if you are not careful. It will quickly overheat the metal and ruin its temper if you don't take steps to keep the heat buildup to a minimum. I start with the right edge of the tool just hovering over the left edge of the spinning grinding wheel. Then I gently lower the tool onto the wheel and slowly - not too slowly but just nice and easy, with a smooth, fluid motion - move it across the wheel and back, then lift it off the tool rest. I immediately immerse it in a pond of water (mine sits at the base of the grinder) for a few seconds, then look at the edge. Yes, I make one pass back and forth at a time. If you don't, when you get close to being finished you will start turning the edge blue. If that happens you have just ruined the temper for that area and will have to go back to the start of jointing the edge all over again. It takes longer, but it’s safer and will allow you to use less expensive equipment.

Step Two: Grinding    [Contents]

Once your edge is jointed, it is time to grind the bevel. A round grinding wheel spinning around its axis will not grind a flat surface, unless you hold the tool to the side of the stone - which I do not recommend. The actual ground surface will be slightly concave, conforming to the curvature of the grindstone. This phenomenon is known as a hollow grind. Many dispute the validity of the hollow grind as they say the edge is significantly weaker than a flat ground edge. I have never had a problem with edge failure so I opt for the simpler route – and for several reasons.

A hollow ground blade actually has several important advantages. First, it is quicker to hone. The less material you have to remove with your water stones, the quicker the process will be. Second, it is easier to sharpen. Honing a tool along the entire width and breadth of its bevel is very hard to do. You must use some kind of jig because any rocking at all will result in a rounded bevel. On a hollow ground blade you are only honing the toe and heel. For those like me who are too cheap to by a blade honing guide, having the ability to set the heel down first allows you to pitch the tool forward until the toe is also on the stone. You know you are honing at the correct angle by feel and the blade won’t rock because the middle of the bevel never comes into contact with the stone. Third, the hollow grind allows you to have an easy indicator as to when you need to regrind your tool. I don’t use expensive tools to measure the angle of the grind either.

Plane blades and chisels are usually ground to around 25 degrees from the long axis of the blade. A few degrees either way won't make that much difference. I don’t spend a lot of time measuring angles unless there is something terribly wrong with the way the edge performs. If the angle that was already there is giving me a satisfactory result, I just try to approximate it - by eye. If a check is warranted, I simply set my sliding bevel to 25 degrees and use it to help me adjust my grinding jig.

My grinding jig has small indicator marks on it to let me know that I have the tool clamped squarely in its jaws. I generally use a try square to verify this, however. (The marks on my tool holder can be made easier to see by rubbing a little chalk into them.) Once clamped, the amount of blade protruding is eyeballed to give me enough that I will hit the wheel and grind some metal off but not grind it right down to the handle. Setting the jig into the tool rest, I adjust the tool rest until the blade is just touching the stone and is at approximately the correct angle. I do this by eye, without measuring. Then I am ready to turn the machine on.

I proceed to grind the edge a little at a time, using the procedure discussed at the end of the section on jointing. Right to left I pass the edge over the spinning stone with a steady, fluid motion. Then I lift the blade, quickly placing it in a pond of water to cool the steel. Check it once in a while to gauge your progress, but when nearing the finished edge, check it at every pass. How do you know when you are nearly done? Stop grinding when the tip of the freshly ground edge meets up with the back of the jointed edge. By eye, this is a difficult thing to see, but here is a trick. When the sparks coming off your grinding wheel start to break over the top of the blade rather than under it, you can stop. This process doesn't take very long on a previously ground edge that you are touching up, but it may take a little while on a new tool with a freshly jointed edge.

Step Three: Honing to 1000X    [Contents]

This step and the next are almost identical. The only real difference is the stone on which you work. So, don’t get discouraged by the fact that I have rambled on so long. The end is somewhere in sight - I promise.

Once I have a freshly ground edge, I remove my 1000X water stone from the pond in which it lives, and I place it directly on the bench. Some people clamp or otherwise restrict the movement of their stones but I find that on the raw plywood surface that I use, the stone stays put. I used to use a piece of countertop with plastic laminate and the stones would slide around quite a bit. For this I find that two 'L' shaped pieces of scrap that are thinner than the stone, clamped to opposite corners of the stone, will keep it in place. I sprinkle some fresh water on top of the stone to clean away any particles from the pond and lubricate it, then I set to work.

I hold the tool at a 45 degree angle to the long access of the stone, set the heel of the hollow ground edge down and rock it forward until the tip touches. When you first do this it seems to take a long time but with practice it becomes second nature. Then I drag the blade toward me, heel first - dragging the toe, the length of the stone. I lift the blade, flip it over, set the back down on the corner of the side of the stone (again at a 45 degree angle - approximately) and rock it forward until the back of the blade is lying flat on the stone. Notice how the tip of the blade is always last to touch the stone. Then I drag the back of the blade the length of the stone to flatten and polish the back, but more importantly remove any wire edge that has formed. Then I flip it over and repeat. Make sure you press fairly hard but you don't need to break the stone. I also rest two fingers close to the corners of the blade to push down on the bevel I ground so that the pressure is evenly distributed. I repeat this over and over until the blade is ready for the next step.

I determine when the blade is ready by feeling the edge for sharpness, and looking at the reflection of the light off the bevel. (In the photograph, the glint of light on the edge isn't the same for both corners of the chisel. This means this chisel isn't square any more and should be jointed again. It happens.) By now the blade should be getting quite sharp and you should see an even glint of light off the polished tip and heel of the blade. It should be even all the way across the blade and fairly narrow. Don't hone until you have polished the entire bevel and none of the ground surface remains. You have gone too far if this happens and you have defeated the purpose of making the hollow grind. Every time you hone the tool in the maintenance phase you will increase the size of the polished part of the bevel until it is nearly used up and you have to start over again. Just polish a little for now, then move on to the next step.

If you are sharpening an iron for a bench plane, not a scrub, shoulder or rabbet plane, you need to hone differently. To keep your corners from leaving marks when you plane it is desirable to make the edge of a bench plane iron slightly convex or rounded. To do this I usually apply slightly more pressure to the corners of the blade during both the grinding and honing steps (2, 3, and 4) and I try to hone the edge parallel to the long axis of the stone. If the blade is too wide I alternate from one side to the other while honing at an angle to the stone.

This procedure will take a little more off each corner than the middle of the blade, leaving a very slight belly in the center of the edge. You can check this by holding a square up to the edge and you should see light passing though at the corners, but only a little bit. The effect should be very slight, otherwise you have turned your jack plane into a scrub. (Don’t do this procedure with a jointer plane – a #7 or #8. They should have a perfectly flat, square edge.)

Step Four: Honing to 4000X    [Contents]

Once you have finished with the 1000X stone, simply repeat Step 3 with your 4000X gold stone. This is a much finer stone and you will feel the difference. Where you felt some resistance to the metal in the previous step, here the blade will glide smoothly across the surface of the stone, and if it weren't for the fact that the water lying on top of the stone turns gray, you would think nothing was happening.

Remember you are not trying to increase the size of the polished tip and heel of your ground bevel. You are just trying to shine it up some more. Repeat, checking the edge frequently until further honing ceases to make any difference. Usually this only takes 10 or 12 repetitions as you are polishing a very small area. This is the beauty of the hollow grind. When done you should be able to shave hair off your arm, or close to it. I like to keep a little piece of hardwood on hand to try out the blade. It should be able to shave very thin slices with little or no effort by now. A truly sharp edge slices end grain thinly and cleanly.

Step Five: Buffing    [Contents]

For straight edge tools I use a hard felt wheel charged with Veritas green honing compound. It is important to use a very hard wheel or you will round off your freshly honed edge and it will only be good for buttering bread. This step has to be exercised with a fair amount of caution lest you undo all you have done.

When grinding, you presented the edge of the tool to the grindstone so that the stone rotated directly into the edge of the blade. When you buff, you must present the blade so that the wheel drags off the edge of the tool rather than rotating into it. If it’s the first time you have used your felt wheel, take a propane torch or a lighter and singe the edge - not too much - while rotating it with the other hand. This will help the wheel hold the buffing compound and polish your tool.

Turn the wheel on and charge the edge with polishing compound. Hold the stick against the spinning wheel lightly and make sure the edge is turned an even shade of dark green. Don’t bother with Tripoli or jeweler's rouge. They aren’t made to cut tool steel. Very gently and carefully, I hold the tool, edge down, with the bevel facing the rotating wheel near the bottom. Watching the angle of the tool so that a line drawn through the honed tip and heel of the bevel is tangent to the edge of the wheel, I raise it and lightly touch it to the rotating wheel. But only for a moment. I then flip the tool over and buff the back the same way. Make sure that the back, like the bevel, is held tangent to the spinning wheel. I may repeat this a couple of times but it doesn’t take much. You will notice upon completion, your tool has a mirror edge on the toe and heel of the bevel, and the edge of the back. It should be sharp enough to perform any woodworking task admirably.

That is all there is to my system, although it took me all this time to explain it. It may not turn out perfectly for you the first time, but take all the chisels you have and, starting with the cheapest one, sharpen them all. You should be satisfied with the results by the time that you have finished.

Maintaining an Edge    [Contents]

Edge maintenance is performed for one of two reasons. First is the touch up, usually necessary when you are using a particular chisel or plane heavily and you want to freshen the edge. To do this I just go to the grinder and charge up the felt wheel with a little green honing compound. Then I buff the edge very briefly. I find this refreshes the tool enough so I can be back at work right away.

The second type of maintenance is that end of the day house-keeping necessary to keep your tools sharp. You don’t need to go through the five step process every time you sharpen your tools. For most tools I only use the jointing step once or twice in its lifetime. I only regrind the edge when I absolutely have to. Your tools can be maintained between grindings by simply following Steps 3, 4 and 5 on a regular basis.

At the end of a day in the shop, those tools I used will get a touch up on the 1000X and 4000X water stones and then a quick buffing. That way, when I come back to the shop, my tools are sharp and ready for use. Proper storage, so that you protect the edges from damage, is also essential. I find that on an average day 15 minutes of sharpening and 15 minutes of putting tools away and sweeping keep the shop tidy and the tools ready for action. It’s a simple routine that I recommend to everyone.

So how do you know when you need to regrind? I find necessary to regrind when I have maintained the tool long enough that I have honed the bevel almost flat. The more times it is honed, the longer it will take to hone – you are polishing an ever increasing surface area. When you have worn the heel and toe of the bevel enough (I didn't have a chisel that was that far gone), and very little of the original concavity remains, then regrind.

Alternately, I may regrind when I am in the finished stages of a project and I need a really sharp plane to put a final smoothing on a carcass side or face frame. I like to use a freshly sharpened tool for this and, if the plane iron is close needing a regrind anyway, I may do it early. It is especially useful to pay attention to the edge of your tools when in the finishing stages of a project and you have complex grain patterns to deal with.

Another situation that may prompt a pre-emptive grind is when the tool is just not functioning properly. If, for example, you have a plane that is leaving big ridges or a lot of tear out, you should inspect your edge thoroughly. This happens to me when I have been grinding the tool for a while, by eye if you remember, and my angle has become either too steep or too shallow. It also happens if you drop the thing or your four year old knocks it off the bench - heaven forbid. In these situations you may have to consider re-jointing the edge as well.

Parting Thoughts    [Contents]

One drawback of water stones is they tend to wear away quickly, therefore requiring periodic flattening. Having been a former user of the Scary Sharp process, I do have a sheet of plate glass that I used to true up my water stones but I no longer use it. If you are a Scary Sharp proponent, take a straight edge to your plate glass. I was surprised to find that mine was far from flat so I use the flattest part of my table saw top, to which I tape a sheet of 220 wet/dry paper. Then using random circular and figure eight style motions, I rub my stone - face down - on the paper until it is flat. If it clogs I squirt it with compressed air. Examine your stones carefully under a raking light and you may be surprised. It’s not too long before repeated use makes them wavy and uneven. Check them routinely. A flat stone will produce a flat tool, which makes a more accurate cut and tighter fitting joint.

If I were to sharpen everything I have in the shop, it may take me several hours to go through all of the procedures I have outlined here. However, with a proper hollow grind, and regular maintenance you do not need a lot of equipment or time to keep a sharp edge on your tools. If sharpening isn’t a pain in your posterior you may actually learn to love it. On USENET, the Scary Sharp process is perceived as the answer to everything but, having tried it for a long time, I can say that I spent a lot more money on silicon carbide paper than I ever did on water stones and I was never satisfied with the results. Some very talented woodworkers swear by it. In my book, if you can't repeat it reliably, it isn’t worth your time and money.

My process works for me, gives reproducible results, and I don’t have to spend a lot of time on this very necessary aspect of woodworking. In the end, however, there is always more than one way to sharpen a chisel. My methods may confound you and elicit streams of profanity. However, it helps to know what works for others. Only you know your budget and habits, but maybe knowing how this woodworker has coped with this oft dreaded task will help you produce and maintain sharp edges on your chisels and plane irons.