Instructables
Picture of Sharpening a chisel
I have unreasonable sentimentality about Stanley Model 40 chisels. I started buying them about 30 years ago just as they were being discontinued. They seem to sharpen easily and hold a good edge. I was always missing the one inch chisel and recently was lucky enough to find one on eBay.

 
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Step 1: Beat up chisel handle

Picture of Beat up chisel handle
When I received it, I noticed that the back of the handle had been hit pretty hard over the years.

Step 2: Badly sharpened bevel

Picture of Badly sharpened bevel
When you saw the bevel, it was no surprise that someone had hit it that hard. It looks like it had been sharpened multiple times but each sharpening had only added another facet to the bevel.

All chisels, whether new from the factory or used, need tuning before they work well.

Step 3: Reason #1 for sharpening

Picture of Reason #1 for sharpening
The primary reason to sharpen a chisel is shown in this photograph. You can see how poorly the chisel cut a piece of softwood and all I was trying to do was pare a small piece off the corner. The chisel crushes the fibers until they break rather than cutting them.

Step 4: Reason #2 for sharpening

Picture of Reason #2 for sharpening
And there’s a second less obvious reason. For 35 years, I have carried a reminder on my left palm of the dangers of working with a dull chisel.

Step 5: The back of the chisel

Picture of The back of the chisel
Ideally, you want to have two perfectly smooth surfaces, the bevel and the back, meet to form the cutting edge. Any imperfections in either will reduce the sharpness of the chisel.

Here’s the chisel back when I received it. You can still see the machine grinding marks left from the factory.
Aaronius1 year ago
Fantastic instructable! Thank You!
David hogg2 years ago
Last comment I promise.
Given the fineness of the mediums you are using I was interested in just how much difference the final polishing of the bevel made so I refinished the bevel on the chisel with stannic oxided slurry on an oiled paper lap. It turns out to be quite significant.[see image] This produces a very slight bull nosing of the bevel. Probably better to use the slurry on a steel lap.

Kind Regards,

DJH.
blade polished IMG_0170.jpg
David hogg2 years ago
Thanks for the test Carlbass. Leaving a satin like sheen on soft wood end grain does indeed appear to be a more more rigorous test than shaving or paring nails.

I was quite pleased with myself that the old chisel [Swedish c. 1910] I was restoring seemed to meet the end grain test till I took a look at my handy work under a microscope.
What appears to the unaided eye as a mirror finish can be deceptive! I still have much to learn. What look like chips out of the edge are in fact tiny corrosion pits on the flat of the blade.

DJH.
blade pair IMG_0163.jpg
David hogg2 years ago
Thank you, that was most instructive. I should have consulted it long ago. I have a rather fundamental and possibly naive question. I sharpen my chisels on the diamond laps I use for stone cutting. I get a mirror finish and they seem to work OK but are they really "sharp"? The test I use is whether I can dry shave [hair] with them. There must be a much more professional test known to the experts?

Kind regards,

David Hogg.
carlbass (author)  David hogg2 years ago
I do the same and shave the hair on my arm. I've seen others shave a fingernail and the best test is to pare a piece of softwood end grain.
nerd122 years ago
i recently got a chisel but i need to sharpen it. Do you have any instructables for how to use an oilstone to sharpen it? I can't get a grindstone. i tried to use a cylinderical dremel bit but it just made it look very polished and still blunt.
Any help Please?
drewgrey2 years ago
Beautiful job on the chisels and the instructable.Another alternate sharpening is for working with melamine and laminates and the pvc edgebanding that is used with them. We have a huge edgebander at work that glues ,end cuts, routes and scrapes top and bottom and then buffs all in one pass....but if you dial it in to perfection any inperfection in your material gets highlighted by having it's finish removed. The solution is to set it close and then final trim and scrape with a hand chisel. This chisel should be shapened normal and then turned over and have a second bevel put on the other side for about 1/16 inch and 5 degrees.Then round the corners slighty so it don't dig in. It is kept sharp but the second bevel seems to make it glide over the laminate while trimming the edge.
Rahere2 years ago
I keep a 8000 slip for the bevel - those water wheels are expensive and take up space I'd rather use for something else.
yomero2 years ago
lovely tutorial, the moment i saw the honing of the edge i thought of a straight razor, and i never imagined this things needed to be so sharp
mje2 years ago
Nice instructable. I use a Veritas sharpening jig, which makes it easy to put a proper bevel on if you don't do this sort of thing every day. I also use the sandpaper-on-glass trick for sharpening as well as prepping the back, going to 1600 grit. Cheaper than waterstones ;-)
cobourgdave2 years ago
Your instructable is great. It has been a very long time since I was taught how properly sharpen a chisel. I agree with all the steps you have shown, with one possible variation. I follow up hand stoning with a leather strop. I have an old shoe sole that puts a very high polish on the blade and assures a razor edge, needed for work on soft wood. Incidentely, the same process should be used on hand plane blades. Thanks.
carlbass (author)  cobourgdave2 years ago
I agree completely. I mistakenly left it out of the instructable but I often strop the tools on a piece of leather glued to a board that I rub that has rouge on it
nspirit2 years ago
OOoohhhhh ... didn't know i had to sharpen my chisel.
In a way it make sense.
Thanks for this instructable that'll be really handy :)
mikeasaurus2 years ago
A thorough write up!
It's funny how sometimes we get used to working with dull tools and don't realize what a difference a sharp blade makes.
Sometimes dull blade is better. Believe it or not a dull knife cuts foam roofing insulation much better than a sharp one does. Drove me nuts to learn it, but I've come to accept the fact today. I wouldn't want to butter my toast with a sharp blade either. But we'd use butter knives on roofing insole.

For everything else I got used to sharp blades at a very young age. 20 years ago I thought I knew everything there was to know about sharpening too. Since then I've learned a thing or two though.

Today for instance I wouldn't consider a chisel edge fully sharpened unless it was stropped. Wire edges are for scrapers.
carlbass (author)  pfred22 years ago
I agree about stropping.
pfred2 carlbass2 years ago
Just something about it. For years I didn't do it and wondered why my edges dulled more quickly than I thought they should. Today I think it was because the wire edge was bending over on the blade. A strop until the wire edge breaks off cures that.
carlbass (author)  pfred22 years ago
They dull more quickly and they're subtly but noticeably not as sharp
pfred2 carlbass2 years ago
Yeah instead of saw sharp they get slippery sharp after stropping. Like you polish out the last scratches on the edge. Do you charge your leather strop with rouge? I have a stick of this red stuff I use. I can't even remember where I got it from. I just know I got it now.
If you're talking about rigid foam insulation, a handsaw cuts it much more easily (and more quickly) than any knife, dull or sharp.
This looks like what we used:

http://img.archiexpo.com/images_ae/photo-g/waterproof-rigid-polyisocyanurate-foam-and-bitumen-insulation-panel-for-roof-449951.jpg

A dull knife goes through that stuff like it is hot butter. A sharp knife sucks though. I've used both. I wouldn't have brought it up if it wasn't different.

I never saw anyone ever try to cut the stuff with a hand saw. Mostly because no one had a hand saw, and dull knives worked so well why would we use anything different?

A good 'ible, well explained & well illustrated.
I agree with mikeasaurus it's surprising how people can get used to dull tools.
I recall many years ago spending most of a Sunday getting a workmates chisels up to standard & another Sunday a week or two later teaching him how to keep them like it, he seldom used them but at least when he needed to they did the job properly.
I have always belived that any tool well looked after & maintained is far more useful than the most expensive one mistreated & neglected.
Any chance you will follow this up with one about maintaining your stones & wheel?
I cannot agree with your statement that just the maintenance of tools makes some better than others. I've been sharpening steel for too long now to believe that all steel is created equally.

So far the best steel I've had the pleasure to sharpen is in some kitchen knives I own. Knives made by Henckels for a company named Hoffritz that were cyrogenically treated. I could cut a Japanese waterstone clean in half with one of those knives, and still slice a tomato paper thin after the fact.
I think you are missing my point; when I say that "I have always belived that any tool well looked after & maintained is far more useful than the most expensive one mistreated & neglected." I mean that simply because a tool is expensive or high quality it does not mean it will perform the job well if it is not looked after.
Imagine trying to cut a waterstone in half with your knife if it had been left in the bottom of a damp drawer rattlling around with your spanners & hammers for a few years, I doubt you would have much luck.
I have a one inch chisel I bought about twenty years ago for about £1.20, I had left mine at home & needed one to trim around a door frame to fit some cables for an air conditioner, it ihas been well looked after & is still sitting in my workshop now, sure it does not hold it's edge as long as my higher quality ones but it does perform a more than adequate job & I still use it regularly.
The ones I mentioned previously I sharpened for my workmate were if my memory serves me made by Marples, not I will grant you the most supremely high quality available not equally they were not exactly rubbish & many people myself included have enjoyed using their Marples tools for many years; his ones howver had been kept in a plastic bag in the bottom of a tool box, three of then had NEVER been sharpened & the forth had a sloping cutting edge & a CONVEX!!! bevel.
I ask you this, if you had to use one or the other given the choice of using my £1.20 dirt cheap but honed & well maintained chisel or his much better quality & far more expensive but blunt & chipped Marples ones.
"Which would you choose?"
Don't be silly. The only right answer is to sharpen the Marples and use your cheap chisel as a putty knife :)
Steel and ateel and of course steel are so different in many kind of capabilities. You never can say that any old one is better than any new one or counterwise.

It is a long time of experiance and the result of many tries to find what is good or not.

I love to see someone who takes care for his tools and knows how to make them usable.
carlbass (author)  Nostalgic Guy2 years ago
Thanks. I'll do another one about sharpening but right now there are two ahead of it about things I've been making
CapnChkn2 years ago
I like that item you're oiling the metal with. I've never seen anything like it. What is that called, or how is it made?
carlbass (author)  CapnChkn2 years ago
I bought it at a local Japanese woodworking store. Here's a good view of the felt applicator

http://www.fine-tools.com/G-applikationsflasche.html
pfred22 years ago
I have some Japanese waterstones. They're OK, I prefer my Arkansas sharpening stones to them though. I'm a westerner. I finish up with a red rouge charged leather strop. Nets me an edge sharp like a razor, durable too. I rough with them synthetic diamond hones. They're not half bad. You should try them. Oh, this is my secret ingredient, get this stuff called Super Clean, or the knock off Purple Power amazing stone lube!

What I really hate about Japanese waterstones is they spall if my shop freezes. Something about water freezing in stones that isn't good you know?
CementTruck2 years ago
Great Instructable.

How much is a good set of Japanese water stones?
carlbass (author)  CementTruck2 years ago
You can buy a combo waterstone with two grits for about $35. That would be enough for most tasks. At the other end of the specturm, you can spend up to $100 per stone -- way overkill unless you do a lot of sharpening