Sharpening tools properly must be one of the hardest lessons to learn in carpentry. And yet the path to success is simple. Unless you’re a tool junkie, or my friend Gary Katz, it doesn’t require fancy or expensive equipment.
Step One: Sharpness is nothing more than two flat surfaces, polished mirror smooth, meeting at an angle. Use a grinder to establish the angle. Thirty degrees is about right, but you’ll soon learn to get it right by eye. Pointier will cut more easily, shallower will be stronger. Grind the bevel side hollow. You will have ground enough when sparks start coming over the top.
Step Two: Check the chisel for square frequently and use a gentle touch. Dip the tool in water or oil often to cool it. (I use an inexpensive magnetic mist sprayer.) If it gets hot enough to discolor you will have ruined the temper.
Step Three: Hone the bevel on an oil-stone or water stone—I use a medium India—secured in a clamp or fixture. If you hold it in your hand you will probably be wearing a band-aid soon after. Rest the tool on the bevel and don’t tip it up or down as you sharpen. Use small circular motions and move over the entire surface of the stone so you don’t wear it hollow. All you are doing is removing the coarse scratches made by the grinder—it doesn’t take a lot of pressure, just a little patience.
Step Four: Hone the back of the tool. Hold the back absolutely flat on the stone. You are polishing out any scratches or pits on the back, making sure the back is flat, and removing the burr left by the earlier steps. This step may take a few minutes on a new tool, but only seconds to retouch a tool that has been properly sharpened before.
Step Five: Stropping is the step most carpenters skip, which is why most carpenters are working with dull tools. I use a piece of leather glued to a block of wood. Charge the strop with buffing compound. My favorite is Herb Dunkle’s Yellowstone.
Step Six: Strop the tool by pulling it backwards over the leather—back side first, then the bevel. Hold the tool flat on the leather so you don’t round the bevel over. In a moment you will be able to see your reflection in the edge of the tool.
Step Seven: When you can shave with your chisel or plane iron, then it’s sharp enough to cut wood—even curly hardwood or across redwood end grain.
(This article originally appeared on GaryMKatz.com)
Should be required reading for every woodworker “WANNABE” So simple so inexpensive and yet so necessary.
I remember an article in Fine Woodworking called Scary Sharp where you’d go through a graduation of fine grit sand papers glued onto glass making your tool sharper than a razor or SCARY SHARP!
I was building a boat last summer and needed my block plane to be “scary sharp” and used the technique you mention.. My buddy didn’t realize just how sharp I had gotten the tool and he lost about a half pint of blood to it the next day!
good article. I do a lot of woodturning so I have both a slow speed grinder (1725) and a Tormek grinder. I mainly use the tormek because I don’t take off hardly any metal. With the price of a good lathe tool, I want to make them last as long as I can. I even run my small pocketknives across the tormek too. They’re sharp enough to shave with. I actually enjoy sharpening stuff.
THANK YOU for speaking up for us Tormek owners! I love mine, too, and I know I have way too many ‘tools & accessories’, but that one sure comes in handy. Yes, it could be done with simpler ‘devices’, but not as quickly and not as accurately. Now maybe that’s my problem and the reason Jed is always poking fun at me!! :)
Thanks for a short but info full article. It brought back memories from 9th grade when I was going to Brooklyn Tech HS in NYC, and the first of two years as a cabinet maker’s apprentice. The very first lessons were about caring for your instruments. Nothing fancy, but with care and diligence a perfectly honed edge can be achieved. A sharp tool is a safe tool that is controllable.
Winter 2008 JLC in Seattle, I asked you your sharpening suggestions (which were exactly as the article shows except for a belt sander instead of bench grinder) during one of your presentations and I remember you dropping your chisel from 5 feet onto a metal floor grate and then digging it into the edge of the grate just to prove it was damaged and in under 5 min it was cutting the hair on your forearm. I felt that I was sharpening well but after that demonstration I added stropping to my sharpening technique and it’s been fantastic ever since. Thanks Jed
Like Mike, I use both a slow-speed grinder for the rough work, then, as of last year, a Tormek T-7. I have been sharpening seriously for about 50 years, and have used just about every conceivable device to improve my results, but nothing I’ve ever used compares to the control, precision, and reproducible results of that Tormek (that took me about two years to save up for). :)
Great article, (those hands look like they have seen some work) but you make it look too easy.
I tried sharpening my tools on a grinder and destroyed the temper on one of my chisels. I tried using a water stone etc. like Frank Klaus demonstrates on his video, but I am not good enough to hold the tool square to the stone either. I tried honing guide but found them awkward and cumbersome. I finally broke down and invested in a Tormek.
I bought a Makita Waterstone sharpener in 1985, it does a nice job and won’t overheat a tool edge. I generally finish up by hand with an 8ooo grit waterstone that leaves mirror finish. I do strop my straigh razor but the very fine waterstone seems perfect for chisels and planes; straight drawknives as well.
What do you recommend for carving and sculpting tools?
The very nicely made Tormek machine, as far as I know, is a way of sharpening just like I do in the article, only in a much more controlled way. Something that it doesn’t do, and which I should have made clearer, is that you can do the hone and strop many times between each grinding (unless you hit a nail). I carry a little diamond hone, and a small strop in my tool box so I can touch up my block plane and my chisels on the job site. I usually grind only when the hollow grind on the bevel becomes flat.
Here’s a little history of how I learned to sharpen: In the early ’70s, when I was starting in woodworking, I had a terrible time getting my tools sharp. My teacher showed me that grinding a bevel, and then buffing the bevel on a buffing wheel with jewelers rouge or tripoli compound would produce an edge you could shave with. But I soon noticed that this didn’t last long, especially on hardwoods. I think this is because the buffing pulls the edge out, microscopically, into a fine featheredge like a straight razor. Also all the grinding ate up expensive tool steel. Eventually I bought a set of oil stones: carborundum, India, Arkansas, and black surgical Arkansas. By working up through them I could eventually get my plane irons sharp enough to shave with. If I was doing this now, I would probably buy water stones instead. Then, in the early ’80’s I worked with an extraordinarily talented, classically trained , woodcarver named Jim Lohmann. He showed me that you can get tools really sharp- “carving tool sharp”- by honing them on an India stone, and stropping them on a piece of industrial belt leather charged with fine carborundum powder sprinkled on with a salt shaker. All the intermediate stones were unnecessary. These strops took a while to condition,and they actually worked better after they were a few years old. Because the leather was thick it could be cut and molded into the same curved shapes as carving tools. I still use mine to do my gouges and parting tools. But about ten years ago, my friend Karl Dennis, a violin maker, gave me a bar of Yellowstone strop compound. I found this to be much easier and quicker to use for straight blades than my old belt leather strop. A piece of pigskin or suede glued to a wood block makes a fine strop, and it becomes conditioned after a few sharpenings.
Like anything else, hand feel, acquired by practice, really helps when sharpening woodworking tools. When I started I could barely get a plane to cut, even with something like a Tormek. Now, thirty years later, think I probably could get a razor edge with a brick and the leather on my boot upper… Someday I’ll figure out how to sharpen kitchen knives, scissors, and my hockey skates!
You were absolutely right in that most people leave out the stropping step when sharpening, I did for years and when I finally did it and realized the difference I never missed that step again!
In this article, it would be helpful to have some grit numbers.
I take out nicks on a 200 grit white wheel at 1725 rpm.
Next, 400 grit diamond stone, 800 grit water stone, 1200 grit water stone, back and bevel on a 6000 grit water stone.
This takes four minutes. I skip the wheel if there aren’t any nicks.
Harold, This will probably surprise you, but I grind on a 60 grit wheel, the coarsest I can get. It cuts fast even with a light touch, and I think it’s actually less likely to overheat the tool. I keep the wheel sharp by dressing often with a diamond dresser. I hone with an India stone- maybe equivalent to a 800 water stone- or a fine diamond hone from the hardware store. Then I strop. The strop grit is probably finer than 8000. After I’ve stropped there is no sign of the grinder scratches. The tool is mirror shiny… But, If your technique works don’t listen to me. Keep doing what you’re doing! One thing I’d like to mention: No matter how sharp a chisel is, it’s going to be very hard to control if the flat side isn’t perfectly flat and the bevel isn’t flat or hollow.
Thank you for filling in the grit numbers. I was curious what grit a medium India stone is.
In all the years I’ve worked with Jed I’ve learned an awful lot about stairbuilding and woodworking in general. The very best thing he ever taught me was how to sharpen my tools! All my tools are “Shaving” sharp. Thanks Jed.
Mike’s a sharpening fool. He’s used the same utility knife blade for a year and it will cut tissue paper.
Jed, I changed the way I sharpen after watching you sharpen a chisel in Providence about 10-12 years ago. You had a small hand turned grinder and a buffing wheel. I couldn’t believe how quickly you sharpened a chisel. Since that time I’ve hollow gound chisels and plane blades freehand on a bench grinder, checking for square and cooling with water as I go. Once there’s a hollow grind on the blade I flatten the back and hone the front on a diamond stone. The last step is to use a buffing wheel on the grinde with some jeweler’s rouge and buff the edge until it shines. It never fails to produce a “shaving edge” edge in a short amount of time. If I were a furniture maker or stairbuilder like yourself the tools may have to be sharper but when it cuts paper easily or shaves the hair on my forearm it’s a remarkable improvement on the tasls I used to go through to achieve unremarkable results. Thanks for that tip many years ago.
Looks good Jed. Have you seen “Ask Woodman” on Youtube yet?
He has some good pointers on sharpening too, and they are videos which for me makes them easier to digest sometimes. Here is the link to his sharpening series:
Keep up the good work!
I strop most things on a piece of wood or mdf, using left over machine buffing compound for automotive paint. The remnants or PerfectIt III or Meguiers left in the bottle that is being thrown away at the local autobody shop will last for months.
“Steeling” with an aluminum rod or flat bar, will take your tools to the next level from stropping, too.
It doesn’t seem to matter what aluminum you use. I have some pieces that I bought from McMaster Carr’s catalog years ago, that will last for my lifetime.
Great Job Jed,
Brings me back to watching my grandfather sharpen his blades.