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Thread: "Land" dimension on a bevel edge bench chisel

  1. #1
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    "Land" dimension on a bevel edge bench chisel

    How important is the "land" height on a chisel used for dovetailing? My set has about 0.040". That seems like it could bruise the bottom of the tail, or else miss the final bit of the baseline between the tails. What am I missing?

  2. #2
    What you are missing is that we cut to the corner with the saw; the chisel does not need to cut the material at the very corner.

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    Quote Originally Posted by Bob Jones 5443 View Post
    How important is the "land" height on a chisel used for dovetailing? My set has about 0.040". That seems like it could bruise the bottom of the tail, or else miss the final bit of the baseline between the tails. What am I missing?
    My paring chisels haven't been measured. My guess is some of them are a bit less than you 0.040". If you are good with a saw, as Warren says, your sawing will take care of the corners. If you saw like me, occasionally you will need to get into the corners with a chisel. Skew chisels can be handy in such situations.

    One of my reasons for using Buck Brothers chisels for paring is their very shallow lands:

    Paring Chisel Side Detal.jpg

    The one on the right is the Buck Brothers.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

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    Quote Originally Posted by Bob Jones 5443 View Post
    How important is the "land" height on a chisel used for dovetailing? My set has about 0.040". That seems like it could bruise the bottom of the tail, or else miss the final bit of the baseline between the tails. What am I missing?
    Bob, there are work-arounds, to which no doubt Warren is alluding. However, for us mere mortals, cutting into the corners of the sidewalls is much easier with a chisel which will not bruise this area. This is especially so when the base of the tail is very narrow (say, around 1/8") and it is not possible to skew a chisel to clean out the sides.

    These tails are quite wide, but it still helps to have a chisel with minimal lands ...



    If you are chopping out the waste from a tail, it helps to have a fit like this ...




    Perhaps Warren could show us his method. I am always up to learn something better.

    Regards from Perth

    Derek

  5. #5
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    Thanks, all. Lots to unpack.

    Warren's comment got me thinking. Remember that I'm just embarking on dovetails. But of course there's the initial saw kerf on the edge of the tail. In this regard a Western saw offers a benefit with its wider kerf. A land wouldn't need to be infinitesimal like on the Buck Bros. or Blue Spruce as long as the top of the land fits inside the saw kerf. Makes sense. With a 1:8 tail pitch, a land could be up to 8 times the saw-kerf thickness (√65 to be exact) before a chisel running parallel to the gauge line would need to touch the tail (assuming the bottom of the kerf is flat).

    kerf = 0.018" (Dozuki) to 0.026" (Western)
    pitch = 1:8
    headroom for land = 0.144" to 0.208" (plenty!)

    Or looking at it another way, how close to the tail could you get with a 0.040" land?

    land = 0.040" (vertical limitation)
    pitch = 1:8
    horizontal limit = 0.040 ÷ 8 = 0.005" (a lot less than the saw kerf!)

    If you still need to whisk away 0.005" of kerf waste, I guess a chisel pointed down along the tail side could do it. These are the things experience will no doubt show me.

    I can imagine that a super-premium tool like in Derek's photos, with its ultra thin land, would afford a level of finesse a master craftsman would appreciate. Give me a few years and I'll let you know if I get there. In the meantime, I'll forge ahead and learn on my Narex set (0.040", 1/4" and up). I read on the Highland Woodworking site that the Narex 1/8" does not have beveled sides so I just ordered the 1/8" Sweetheart 750 (land = ?). Now I can begin to discover all the other chisel properties that matter, like hardness and best bevel angles for chopping/paring, soft/hard wood, etc. What could go wrong?

  6. #6
    Thanks for doing the calculation, Bob. I have presented this before, but it seems to go over people's heads.

    In the 18th century, chisels were usually not beveled at all. However chisels for a cabinetmaker were a lot thinner than today's clumsy offerings. The chisels in the Seaton Chest (1796) were around .05 thick at the bevel, which, as you point out, is easily within the safe dimension. When Lee Valley was making prototype chisels in 2011, I suggested on one forum that they were way too thick. Rob Lee came on to tell me I must be confused.

    Here are some chisels I use for dovetails. The newer one (2008) is .055 thick at the bevel. The older one (1830) has been used quite a bit, but was almost certainly thinner than .05 when new.

    chisels 5,6.jpg
    Last edited by Warren Mickley; 05-24-2020 at 8:26 AM.

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    Warren, I also prefer thinner chisels than the Veritas. As modern bench chisels go, they are among the better designs, and they have excellent steel. However my preference (again among modern chisels) is a blade the thickness of Blue Spruce. I wish Veritas made the chisels thinner, or BP used steel other than A2 (the blades take and hold a decent edge, but are not nice to sharpen).

    Having determined that I am not arguing with your choice of chisel design, as far as I know, the last time your chisels were available (other than the occasional flea purchase) was 200 years ago. The methods you advocate do not apply in the 21st century other than for the few with your chisels.

    Regards from Perth

    Derek

  8. #8
    Derek, Bob's post must have gone over your head. Many chisels available today are within the parameters he calculated. Bob,s own set had plenty of clearance.

  9. #9
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    Gee Warren, is "civility" in your vocabulary?

    And yes, my eyes glaze over when it is the weekend and I need to do some in-depth thinking. 15-hour Telehealth week days do that. So you will have to explain it simply. Perhaps try metric

    Regards from Perth

    Derek

  10. #10
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    Bob,

    I got a set of the new Stanley’s as my first set of chisels. Overall they work pretty well for me, but I do find the land on them a little too large for cleaning out the corners of dovetails with small pins. With larger pins I find I can skew them a little to get into the corners, but with narrower pins, you don’t have much space between the tails. I addressed this by grinding down the lands on my 1/4” chisel slowly and carefully. I just needed to do that on the very tip of the chisel. It helped quite a bit.

    i haven’t measured the size of the lands, but I also noticed on my set they are a little inconsistent from chisel to chisel, so your 1/8” may come with small enough lands out of the box.

  11. #11
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    Quote Originally Posted by Ben Ellenberger View Post
    Bob,

    I got a set of the new Stanley’s as my first set of chisels. Overall they work pretty well for me, but I do find the land on them a little too large for cleaning out the corners of dovetails with small pins. With larger pins I find I can skew them a little to get into the corners, but with narrower pins, you don’t have much space between the tails. I addressed this by grinding down the lands on my 1/4” chisel slowly and carefully. I just needed to do that on the very tip of the chisel. It helped quite a bit.

    i haven’t measured the size of the lands, but I also noticed on my set they are a little inconsistent from chisel to chisel, so your 1/8” may come with small enough lands out of the box.
    A few light strokes and scrapes with the tip of your marking knife can usually clean up any little bits left at the junction of vertical saw cuts and the floor of the joint, a situation that can happen to anyone. There's always a junction with a stopped saw cut, as in dovetailing. They usually need a little crisp up so don't hang your head too low. Just do it and move on.

  12. #12
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    Actually, that is a good point. I do grab my marking knife to clean up corners some times.

  13. #13
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    Quote Originally Posted by Ben Ellenberger View Post
    Bob,

    I got a set of the new Stanley’s as my first set of chisels. Overall they work pretty well for me, but I do find the land on them a little too large for cleaning out the corners of dovetails with small pins. With larger pins I find I can skew them a little to get into the corners, but with narrower pins, you don’t have much space between the tails. I addressed this by grinding down the lands on my 1/4” chisel slowly and carefully. I just needed to do that on the very tip of the chisel. It helped quite a bit.

    i haven’t measured the size of the lands, but I also noticed on my set they are a little inconsistent from chisel to chisel, so your 1/8” may come with small enough lands out of the box.
    Ben, the first draft of my post included a mention that I might consider grinding down the edges. I edited it out because my posts tend to go on and on. But the idea is staying in my list of possibilities if it comes to that.

    Land problem solved. Next will be my technique, steel properties, honing angles, etc. as I tell my boys, it’s called “experience.”

  14. The way to get into dovetail socket corners, is to slightly skew the chisel, while moving it forwards at 90 degrees to the work.

    I don't think people mention this and I don't understand why.

    David Charlesworth

  15. #15
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    David, I have mentioned the same - and usually with the saw kerf as a release cut in mind. The issue I have is that the narrowness of the dovetails I often make prevents skewing the blade except at the entry. Everything has a work-around. It is possible to find and use an even narrower chisel on the inside - I have a 1/16" - but all this is becoming less and less efficient. A well-fitting chisel, with narrow lands (they do not need to be sharp) is a better choice in my opinion.

    There are times when the width of the baseline is the width of the socket (saw kerf included). The lands then make a difference. Here is a photo of Christian Becksvoort marking his tails to fit his chisel. In this case, the lands matter. He uses LN chisels ...




    Regards from Perth

    Derek

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