Why do chisels have to be sharp?

[Tim Douglass]

Sounds like you've been in my shop.

-- "We need to make a sacrifice to the gods, find me a young virgin... oh, and bring something to kill"

Tim Douglass

[Bill in Detroit]

Ya know something ... when you use a dull chisel, you just whack it harder. And the next time you use it, you whack it still harder. And harder and harder.

Long past the point of cutting, you've been pinching and yanking fibers free for quite a while.

It's very difficult to leave a clean edge when you do that. Your control has been marginal (at best) for quite a while. And still the tendency is to just whack it a little harder because you only need to make two more cuts.

A plane will FORCE you to sharpen it. A dull circular saw blade will send up smoke signals. A dull hand saw blade will work your tail ragged and give you nothing much in return. And who can be certain how the shovel was supposed to feel with that particular load of dirt, anyways?

But a chisel will keep making cut-shaped marks in the wood as long as you can keep whacking it harder and harder.

Of course, when you lay aside the mallet and try to make a hand-powered paring cut, that dull chisel is gonna look at you and just grin.

Use a sharp chisel. ;-)

Bill

[Mark & Juanita]

I think ya'll are missing Mike's point. What I am reading from his post is that he does not disagree that tools need to be sharp, just that the way articles are written, only chisels seem to be singled out and specifically called out to be "sharp" chisels. What (as I read it) he doesn't see is an article that uses the words, "with a SHARP scraper ... " or "with a SHARP shovel ..."

+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+

[Puckdropper]

Bill in Detroit wrote in news: [e-mail]:

*snip: Wacking the chisel*

Somewhere I got the impression that a good woodworking chisel was one that could cut through the wood with no help from a hammer or mallet. Perhaps that was one of those "happiness is..." moments?

And a sharper wit. ;-)

Puckdropper

[bridgerfafc]

OK, how about this:

chisels *look* a bit like screwdrivers, or paint scrapers, or pry bars, or flower garden digging tools... and sometimes get used for those things, especially by beginners. so in beginner level tutorials, it makes a lot of sense to *specify* that a chisel needs to be sharp, where it's not so necessary to specify that jointer blades need to be sharp.

nah, that couldn't be it.....

[bridgerfafc]

20-30 seconds at a pop.

for my at-hand chisels, I keep a 600 grit diamond stone close and touch the edge up before it gets dull. for some specialty chisels I'll go to a finer stone, but they cut pretty well at 600 grit.

I keep 'em dry.

[Rod & Betty Jo]

Does anyone know(or where to find) the equivalent grits between oil, water & ceramic stones, diamonds and sandpaper? Rod

[George]

I believe stones are all reported in CAMI terms, which is to say grains/inch.

[B A R R Y]

[B A R R Y]

[CW]

Now that someone has given you a link, be aware that comparisons of that type are of very little value. The cutting characteristics are very different between materials.

[Phisherman]

Try comparing the two: a sharp chisel and a dull one. It's almost like two different tools. Power tools show less differences: slight bogging down, burned wood, hairy cuts, etc.

[Rod & Betty Jo]

read".... Rod

[Mike Marlow]

Oh, I don't think anyone really missed the point Mike. In fact I think the fact that everyone really did get the point is evidenced by the humorous responses. Who can really answer the question seriously, though? It's kind of like people calling the thing in your basement a Hot Water Heater. Hot water needs no heater, but that's what it's called. In like manner, for some reason the admonishment for a sharp chisel has taken on a life despite the obvious redundancy or inexplicability of it.

[Doug Brown]

[Mark & Juanita]

Maybe because, in times past, before all the insulation on the things, they really were hot. So they were hot, water heaters :-)

+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+