Sharpening
I am not trying to glaze over this topic, but sharpening is simple; grind, hone and go back to work. I am not over fussy about how I get there, but I need to have sharp cutting edges to get anything done efficiently. How do I define sharp? If you can’t shave hair easily, it’s not sharp. Sharpening can be as complex or as simple as you want to make it. It can be done from a very crude level or it can be turned into an art from and I think I fall somewhere in the middle. I am pretty practical about it, as sharpening has only one purpose and that is to get me back to work.
Flattening the Back
Sharpening should start at a point that many people ignore, including me for a couple of years, and that is on the backs of your blades and chisels. Having a flat polished back is crucial to getting the best edge you can. No, you don’t have to polish the entire back, but the first 3/8″ or so is crucial.
Use coarse carborundum powder and water for the initial flattening and then work your way through your stones. I have found it’s best to use the carborundum and water on a small steel lapping plate. Keep the mess outside and give yourself some help by using a short block of wood to apply pressure.
To keep the blade and block from moving around on each other and you, run a screw into the block that projects a bit less than the thickness of a plane blade. Position the block so the screw comes out in the slot of the blade. Place chisels, and other small and narrow blades, to the side of the screw.
Grinding the Edge
Somewhere along the line you will have to grind blades and chisels, either after frequent honing or to make them square from the factory. I use a hand grinder. I got my grinder out of my grandfather’s garage and it is a lot older than I am. I still remember cranking this thing as fast as I could back when I was 5 or 6 years old. Fortunately, it seems to have come to no harm.
There is a bit of the pat your head rub your stomach skill involved when using a hand grinder, but it does not take much practice to get used to it. There is a big plus to using a hand grinder as well, it’s hard to ruin a blade due to the low wheel RPM.
I don’t worry too much about getting a hollow grind as it is a byproduct of using a grinding wheel and it is not crucial to my honing style.
Something to keep in mind, I always crank my grinder so the wheel comes down into the blade. This way the heat generated by grinding tends to be carried into the body of the blade and not out on to the leading edge where it poses a risk to the temper of the edge. Once you lose that temper you have to grind past it.
Angle of grind for different types of blades and chisels
25 degrees planes, spokeshaves and bench chisels
30 degrees mortise chisels
35 degrees combination plane irons
Grinding Curves
To make a curved edge, grind down the corners and pivot the blade to shape your curve. You will probably find that it is easier to grind a curve than it is to grind a straight edge. As with any grinding keep the blade moving. Don’t leave it in one spot for long or you could ruin the temper by overheating the blade. Even a hand grinder moves fast enough to burn a blade.
Honing the Edge
I prefer oilstones because they are less of a mess than waterstones and with care they will outlast you. I have a coarse carborundum, Washita, Soft Arkansas, Hard White Arkansas, and a Hard Black Arkansas. These will set you back about $200 (2000 prices) but you will never need to replace them.
I have fixed my stones to a bench for ease of use and attached covers to keep out any dust. The lubricant I use is 100% mineral oil made specifically for honing. I don’t recommend using kerosene for health reasons. I get the honing fluid all over my fingers and soaking in a solvent, such as kerosene, is not good for you. Also, kerosene will let your stones clog up faster than oil will.
One other note about honing oil. I have found that the finer the stone the less oil you need to use. This will make your stones cut much more effectively. When there is too much oil on your finer stones, your blades and chisels tend to skate across the surface.
To clean up my stones during use, I wipe them with old cotton napkins, for the most part these give up very little lint. Wiping your hands with wood shavings helps to remove oil from your hands if you need to get right back to work and don’t want to leave prints on your work. Do not wipe all of the oil from your blades if they are being put away, as a small amount of oil will help prevent rust from forming.
The important thing to remember is that you do not need to hone the entire bevel. The only part that cuts is the leading edge, so I only hone the first 1/16″ or so of a fresh grinding job. You can usually hone a couple of times before heading back to the grinder, so between grindings I only hone as much as I need to restore the edge. And keep a loupe handy for checking your progress, it will show you all kinds of things that your eyes alone will miss.
Work your way through all of your stones. I don’t remove the wire edge until the final stone. This final stone varies depending on what I am honing whether it is a chisel or plane blade. For many of my blades I stop with the Hard White Arkansas. The finest edge is not really needed on all of your blades; so I only use my Hard Black Arkansas for smooth plane blades, shoulder rabbet plane blades and bench chisels.
Periodic Maintenance of Your Stones
No matter how careful you are with your stones they will need to be cleaned once in awhile. This is not very difficult and will prolong the life of your stones. I use a stiff brush and dishsoap in the sink. Just scrub until most of the dark residue is gone from the surface of the stones. You can’t get it all but most of it will come off.
After a couple of years of use (or sooner), you will need to flatten your stones. I find this is easy to do using carborundum powder on glass with water as a lubricant. I use the backside of the glass I use for flattening planes to do this. I got my carborundum at a rock shop; use both coarse and fine grits depending on the stone you are working with.
Use lots of water and add fresh grit when it feels like it is no longer cutting. There is a distinct difference between fresh grit and grit that is shot. Use the whole surface of the glass or you will dig a hole and this will create problems down the road. A hollow piece of glass will put a convex surface on your stones not the flat surface you are after.
Plane and Spokeshave Blades
For the most part, an almost straight blade that feathers out at the edges is what you are after. Just apply a little pressure at the sides of the blade during honing or sometimes the natural wear of oilstones will take care of this for you.
Why a gently curving edge? I said it before but I think it bears repeating, a slightly curved edge makes bench planes work better and is a must on a smooth plane. The curve eliminates the corners digging in and makes fixing twist on edges and narrow pieces easy. It also helps to remove unwanted bevels or put on wanted ones.
Something else about plane blades. There can be a vast difference in the quality of blades you have for your planes. If you have double-checked your sharpening technique and it is not to blame, it could be your blades. I have had very good luck with Record irons, even though I use Stanley planes.
To make things a bit easier when honing spokeshave blades, I made a handle that holds their short blades. To make this handle, I cut a kerf into the end of a short block with my ripsaw. I just push the blade into the kerf and friction holds it in place. This gets my fingers away from the stones and gives my hands something to grasp onto. If you find the slot cut by your saw is a bit loose, use a machine screw and nut to pinch the kerf down on your blades.
Chisels and Specialty Irons
I used to think the only “true” way to sharpen chisels was using just my hands to hold the blade on my stones. Then I bought a honing guide. I bought my guide mostly for specialty irons, but it works so well with all of my chisels that I wouldn’t want to sharpen them without it now. The more consistent results I get with the guide means fewer trips to the grinder, which translates to less time spent sharpening.
It is very easy to set a honing guide with a ruler or by making a guide block. This block is just a template for setting the same angle on your blades each time. I have a single block of wood with three settings for the angles I use most.
You could also make your own honing guide but I don’t think it would be worth it. Do buy one of the better guides available. Mine was made in England and cost around $17. Stay away from the cheap ones, they are not made properly and chances are, they won’t put a straight edge on your chisels.
When sharpening bench chisels I almost always stop honing on my Hard Black Arkansas stone. I don’t do rough work with my bench chisels so having them as sharp as possible is for the best.
Combination plane irons on the other hand, need to be tough rather than razor sharp. So generally I stop honing with my Hard White Arkansas stone. This needed toughness is also why they are ground at a 35-degree angle prior to honing. Stopping with the Hard White Arkansas is also appropriate for mortise chisels.
Saws
By no means am I all that good at sharpening my saws and for me to try and tell you how to do it would be ridiculous when the book I learned from is very good and still available. The book is “Keeping the Cutting Edge” by Harold Payson and it is available from Woodenboat Publications. I do not do everything he suggests, but he definitely knows more about it than I. This book will put you on the right path.
When first learning to sharpen, use restraint, as few people are available to fix your mistakes. Most saw shops I have talked with just don’t have the know how to deal with any but the most basic of saws, large tooth rip and crosscut saws. Letting them have a fine tooth backsaw could be disastrous. Ask a few questions to find out if they can fix your saws.
All that I can add to this book would be a recommended size of files list. Taper files are getting harder and harder to find, so taking your saw down to the store to “fit” the proper file is frequently no longer possible. The most likely source for taper files is one of the tool catalogs you get in the mail. By no means is this list all-inclusive, but these sizes do work for me.
Saw Recommended File
Rip 5 tpi 7″ Taper
Crosscut 8 tpi 6″ Slim Taper
Panel 11 tpi 6″ Double Extra Slim
Tenon 15 tpi 4″ Extra Slim
Dovetail 20 tpi 4″ Double Extra Slim
Saw Sets
I have two saw sets, one is for coarse tooth saws and the other is for finer toothed saws. If you want good results you will need both sizes. My saw sets are both of the “plier” type.
Be careful when using a saw set. If you try and set a tooth opposite from the way it already goes expect the tooth to break off. My ripsaw is missing a tooth because I learned this lesson the hard way.
Saw Vise
I found an old iron Sargent saw vise in my grandfather’s garage and while you may not be so lucky, they are frequently available at stores that sell old tools and other junk. The other route is to follow the instructions given by Payson in his book and make your own.
Scrapers
Sharpening is critical in getting the most out of any scraper. While a file will put a usable edge on any scraper, if you want to do more than scrape paint you will have to polish up the edge of your scraper on your sharpening stones. The edge must be straight, true and polished, and the first 3/8″ of the flat sides must be polished as well. This is the only way to get your scraper to cut cleanly enough to avoid the use of sandpaper.
After polishing is finished, you can create the hook that does the cutting by making a few passes with a burnishing tool. My burnishing tool is an old saw file that my great grandfather ground off the teeth and polished up years ago. That’s another point to consider, your burnisher must be polished just as well as the edges of your scraper. If it’s not, it will leave minuscule nicks in the freshly burnished edge.
Sources
Due to the difficulty of finding a good hand grinder, I was pleased to hear from a friend of mine, John Brown, in England that a hand grinder is once again in production. I have not used one but the word is that it is of very good quality. I don’t know of a distributor here in the U.S. but you should be able to get more info at this address:
Ross Buchanan Tooling
P.O. Box 60
Gerrards Cross SL9 8XB
-England-