Why do chisels have to be sharp?

[Mike Dembroge]

Why is it that whenever I read an article that describes using a chisel for something, the chisel always has to be "sharp"? "Clean out the mortise with a sharp chisel." "Square up the corners with a sharp chisel". Why does everyone, it seems, single out chisels as the only tool that needs to be sharp.

I never see them say or write, "rip into strips on the table saw using a sharp blade." "Flatten the boards on the jointer using sharp knives.", "Run them through the planer with sharp knives installed.", "Use a block plane, with a sharp blade, to clean up the edges."

It has always struck me as odd that writers and authors always mention "sharp" when discussing the use of chisels and not other tools. Is it really more important for a chisel to be sharp than any other tool?

Just an observation.

Mike

[Lowell Holmes]

Because many do not know what a sharp chisel and/or how to achieve a sharp chisel. :-)

[Jim]

Back in the days before carbide blades became so prevalent, people said always to cut your wood with a sharp blade. People also still remind us to use sharp jointer blades because carbide blades are not very common.

Jim

[tom watson]

The most important reason is that a dull chisel will hurt you quicker than a sharp chisel.

That may seem to be counterintuitive but the reasoning is that a great deal of force will have to be used on a dullish chisel and that force may be redirected at you, rather than towards the work.

[Father Haskell]

Then you're not reading enough.

A dull chisel is far more likely to cut you than a dull plane iron. It also does a poor job paring or chopping.

[John Grossbohlin]

That's easy... it's so that your son can drop them on the concrete floor in your shop. My 9 year old son did that to the shaving-sharp chisel he was using last night while I was giving him more training in cutting dovetails by hand. Took the corner right off it!

With that I had to regrind the chisel back to good metal before moving on to Arkansas stones. He was getting inpatient while I restored the cutting edge and started kiddingly complaining that I was cutting into his work time! I reminded him that he damaged the chisel. To that he responded, "No, you did." I asked, "How do you figure that, you dropped it?" With a mischievous grin he said, "You're fixing it so you must have damaged it." Kids! ;~)

John

[Leon]

Because a "cold chisel" is not sharp enough. ;~)

[DJ Delorie]

Woodcraft puts that on their training descriptions. "Bring a sharp gouge". I asked them why once, and they said that if they didn't say that, people would bring dull ones.

Maybe it's because chisels and gouges are tools where the force on the tip is generated by (or controlled by) your hand, instead of a motor? Therefor, it makes a difference if it's dull - a motor can force a dull saw blade through wood, but it's much harder for your hand to force a dull chisel through wood.

Aren't dull chisels used for scraping paint, anyway? ;-)

[Mike Dembroge]

Good point. I understand that dull tools are more dangerous (ax comes to mind), and I didn't think of the safety issue. My point wasn't so much that a chisel must be sharp, but rather that the chisel seems to be singled out exclusively. Like I said though, I probably didn't think of the safety angle.

Okay, back to work now...

[Mike Dembroge]

Really? Do you have an example of something in a recent article or publication where a tool, other than a chisel, was mentioned as needing to be sharp?

A dull tablesaw blade can cause all sorts of problems too. No?

[Mike Dembroge]

[snip]

Kinda tough to argue that kind of logic ;-)

mike

[Joe]

As long as we're pondering such questions....

Why do companies tout their products as being constructed of 'space-age' materials?

The space age's golden period was in the 1960's.

Just wondering.

jc

[Dave Balderstone]

It's code for "don't use your chisel as a screwdriver or to open paint cans, you idiot."

[sweet sawdust]

[Father Haskell]

pm, "Mike Dembroge"

Yes. Bench planes. Card scrapers. Files. Handsaws. Shovels...

Hatchets. ESPECIALLY hatchets. They're not sharp enough to bite, they glance, sometimes into pieces of meat belonging to say, you. Jerry Garcia lost one finger this way. Tony Iommi from Black Sabbath lost two.

Doesn't leave much else besides hammers.

Slightly harder feed, mostly. I'm still using the Systimatic 50 tooth combo that came with my saw 12 years ago, never sharpened.

[Peter Huebner]

I expect that may have something to do with the fact that materials science really advanced in leaps and bounds, particularly in ceramics and alloys, in connection with space research. So the association probably kinda stuck.

-Peter

[Mike Marlow]

Geeze Mike, everyone knows the answer to this. Sharp chisels are for paring wood. Dull chisels are for removing common head screws and for prying stuck objects. It's all about the proper tool for the job.

Man - ya gotta explain everything to some people...

[Swingman]

Not always. Never heard anyone say "Open that paint can with a sharp chisel" ... but it happens anyway.

[splinter]

Just curious....how much time do you guys spend sharpening....say a

1/2 in. chisel that has dulled from normal woodworking.....what grit stones do you use/ brand/ water/oil......and what do you use to keep them from rusting?

[Swingman]

Books have been written about this subject ... but some of us just go buy a new one. ;)