Chisel Chopping – How hard is too hard?
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My chisels are sharp, having been sharpened at 25(ish) degrees to 1200 grit, and able to test cut paper. When I pare/chop, it might take 6-7 passes on each side to finish pare/chopping the waste of a dovetail in 3/4″ pine, using a 1/2″ chisel and wood mallet. When I watch people like Paul Sellers on YT, they seem to get it done in 3-4 cycles, even in harder wood. I get concerned with how hard I’m whacking the chisel, and if it will damage the end, but I still feel like I’m hitting fairly hard. My paring angle is pretty long, so I don’t think it’s an issue with the chisel bevel bottoming out.
Should I be hitting harder, not so concerned with hurting my chisel? Or am I on par?
7 December 2018 at 4:33 pm #553778It takes me more chopping than paul too, Im more concerned about the knife line moving than my chisel. Paul strikes with 50 years of confidence, I do not.
7 December 2018 at 8:47 pm #553784Just watch your knifewall. Make some practice cuts in your wood of choice along a knifewall. Leave part un touched.
Chop and ck with a square and knife to see how far you moved the knifewall back. If back you hit too hard if it hasnt movd hit it harder til it does, then lighten up your swing til it quits moving again.How likely you are to damage your chisel handle depends on what the handle is made of. Some chisels are made for paring and should not be hit. But most chisels you might want to use are pretty strong. For example, I have some Narex and have bashed them pretty hard while mortising. I have barely scuffed them. And the same with the Marples blue plastic handle chisels I have used. Lie Nielsen uses hornbeam not only for their bevel edged chisels but also for their mortise chisels. I bet that can take quite a beating. I have a few of their bevel edged chisels, but given their cost, I have been nervous about hitting them too hard. Give me a few more weeks and I will probably try them for mortising. On the other hand, you see a lot of old mortise chisels, made for bashing, with large chips and cracks. Oh well.
My guess is that Paul and others actually hit their chisels a lot harder than you or I do, even if it looks effortless. And I would also bet that their chisels are sharper, even if yours cut paper. Here is a thought. You sharpen to 25 degrees. For quite a while my chisels seemed so very sharp at first and would easily cut paper, but they dulled very quickly. I finally figured out that I was hollow grinding to 25 degrees and then honing a thin edge. Because of the hollow grinding, the edge was, in fact, probably a lot less than 25 degrees. In any event, that might working for light paring, but it made the edge very fragile. My edges rapidly and visibly crumpled when I tried to cut dovetails. I assumed it was the steel, but once I began practicing Paul’s method of sharpening, which is likely to give you an edge more like 30 degrees, my chisels stayed pretty sharp even while mortising. Just a thought.
Pay attention to whether Paul hits faster than you rather than harder; in other words, blows per minute. Paul may be faster because….he’s faster. The thickness of the chip is another factor: Too thick and progress slows, but too thin wastes time. Time spent placing the chisel and ejecting chips are other factors. Put these together, and it can add up. Confession: I’m still slow, but I think these things are a big part of why.
Sanford’s advice about edge failure is excellent. Just feel the edge for a bur periodically. If you feel one, the chisel isn’t sharp any more. You may feel it appear after just a hit or two, and this would suggest edge failure. I need 30 degrees or a bit over 30 on my O1 chisels for chopping, depending on the wood, but my stupid A2 chisels need several degrees more. I sometimes wonder if that would make them inherently slower for chopping.
Seems unlikely that a softwood like pine would dull your edge so quickly. A couple of things that occur to me:
1) Cutting paper is a nice test, but shaving every hair it touches might be a better test of sharpness.
2) are the chisels new (or unused)? A fair number of chisels and planes, even high-end ones, have this issue when new. The steel at the tip is weak due to decarb, so you need to grind a new bevel, then blunt the tip and grind yet another new bevel, then sharpen and hone. This generally removes enough of the weak metal at the tip to get into the good steel beneath. Chris Schwarz has the details if you want to read more: https://www.popularwoodworking.com/tools/woodworking-hand-tools/chisels/why-some-new-tools-have-poor-edge-life/
3) Ultimately, as mentioned above, expecting to be able to do what Paul can do is not realistic. If you could lift half as much weight as the current Olympic gold medalist, you’d still be a strong person, so producing good results in twice the time as Paul is still fine for any amateur. You’ll continue to improve over time.
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