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Thread: Dovetail waste help sought

  1. #1
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    Dovetail waste help sought

    As an outgrowth of my dovetail guru question I thought I'd ask about my stumbling block. It sounds silly but clearing out the waste has been what has traditionally given me trouble. I have tried both using a fret saw and a chisel only. I went through a full package of Pegas blades and didnít get a saw done when I used my fancy Knew Concepts fret saw.* Chiseling: the first time I gave it too much Welly one joint and went paste the baseline. Then I used a different wood** to go to soft pine and it crumbled like anybodyís business. It just seems that though I know how I should do it, I always screw up in some small (or large) way.

    Help me Obe Wan?

    * I got lots of suggestions of what I was doing wrong but it was beyond me to actually make my hands do what I needed. I do now have a coping saw and wooden turning saw.

    ** It was very thickly planed 4/4 birch. This is also what I tried the fret saw on.

  2. #2
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    I have watched Paul Sellers do his dovetails.....and he always cuts a little back from the baseline....from each face...until the chops meet in the middle. Peels a bit up to the knifed line, to give the bevel a bit of room to push waste away...He also leaves a bit of a "porch" out on the end, for support. Once 99% of the waste is gone, he then pares away the remaining 1%...

    The ONLY time I use a coping saw...I use it like a rasp, to clean and level things out...coping saw blade can get into places a normal chisel can't...

    A fret saw is nice ( and some are $$$) but really useless in doing half blind sockets...

    Was working with 3/8" thick Maple on the last project...
    A Planer? I'm the Planer, and this is what I use

  3. #3
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    4/4 is pretty thick stock to get any speed out of a fret saw. One would have to cut slow and careful to prevent snapping a blade.

    My experience with the Knew Concepts Fret Saw was very much different than yours. The Knew Concepts saw made it easier to get blades up to a respectable tension, they should ping when plucked. I haven't purchased any Pegasus blades yet. The blades at Lee Valley have worked well. The blade life with the KC saw is much longer than what my other fret saws have done.

    Then I used a different wood** to go to soft pine and it crumbled like anybody’s business.
    This sounds like your chisel might need a good sharpening. One test of an edge's sharpness is how it pares softwood:

    Paring Socket.jpg

    Trying to take all the wast in one cut can cause crumbling.

    If you can come up with a couple spare 1/4" chisel you might want to make a pair of skew chisels:

    1:2%22 & 1:4%22 Skew Chisels.jpg

    These are good for getting into the area at the bottom of pins & tails.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
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  4. #4
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    Quote Originally Posted by Jim Koepke View Post
    4/4 is pretty thick stock to get any speed out of a fret saw. One would have to cut slow and careful to prevent snapping a blade.

    My experience with the Knew Concepts Fret Saw was very much different than yours. The Knew Concepts saw made it easier to get blades up to a respectable tension, they should ping when plucked. I haven't purchased any Pegasus blades yet. The blades at Lee Valley have worked well. The blade life with the KC saw is much longer than what my other fret saws have done.



    This sounds like your chisel might need a good sharpening. One test of an edge's sharpness is how it pares softwood:

    Paring Socket.jpg

    Trying to take all the wast in one cut can cause crumbling.

    If you can come up with a couple spare 1/4" chisel you might want to make a pair of skew chisels:

    1:2%22 & 1:4%22 Skew Chisels.jpg

    These are good for getting into the area at the bottom of pins & tails.

    jtk
    Think my issue with the fret saw was the lack of control/feeling in my hand but who knows. I had the same thought with with sharpness and it would work for about one socket and Iíd have to sharpen again. Of course the particular white pine I had was super, super marshmallowy.

  5. #5
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    OK, a lot going on. Maybe I can offer some insight into some of it.

    First, I've never used a fret saw, but with coping saws I have to fight my inclinations and reduce pressure on the blade and just let it cut at it's own rate. If I press "down", (to the side when clearing dovetails,) any number of bad things can happen.

    Next, with a Knew Concepts saw, since they're stiffer, it's tempting to cut on the familiar push stroke. The saws do tension the blade better and allow this. But, for me, that only works while I can maintain perfect control. I am much more successful when I cut on the pull stroke, even with the Knew coping saw. (It only feels weird until you have practiced it for a while.)

    Lastly, the go to blade these days seems to be Pegas. But which tooth pitch is recommended often seemed to be different from what was sold when I was looking. I've found the 18 tpi skip-tooth model to work well for me. TFWW sells it, and I see LV now sells Pegas blades and has it too. I was privileged to take a class with Chris Gochnour and he hoards a stash of (Craftsman?) blades he bought over 20 years before and are now discontinued. But he grabbed my saw to demonstrate an answer to a question and like the Pegas I was using well enough to take note of the brand and model.

  6. #6
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    Quote Originally Posted by Tony Wilkins View Post
    Think my issue with the fret saw was the lack of control/feeling in my hand but who knows. I had the same thought with with sharpness and it would work for about one socket and Iíd have to sharpen again. Of course the particular white pine I had was super, super marshmallowy.
    Oh, another thought. I think Derek has an article on his website about making a new handle for a Knew Concepts saw. Maybe a different size or shape would help?

  7. #7
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    If you are crushing fibers, then your chisel is not sharp enough. I think I would concentrate on using only a chisel until I got that method down, then move on to more sophisticated methods, like a Coping Saw, Dovetail Alignment Board, Offset Method, and the like.

    I spent a week learning Paul Sellers' method, so I am partial to that.
    Regards,

    Tom

  8. #8
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    Quote Originally Posted by Tony Wilkins View Post
    As an outgrowth of my dovetail guru question I thought I'd ask about my stumbling block. It sounds silly but clearing out the waste has been what has traditionally given me trouble. I have tried both using a fret saw and a chisel only. I went through a full package of Pegas blades and didnít get a saw done when I used my fancy Knew Concepts fret saw.* Chiseling: the first time I gave it too much Welly one joint and went paste the baseline. Then I used a different wood** to go to soft pine and it crumbled like anybodyís business. It just seems that though I know how I should do it, I always screw up in some small (or large) way.

    Help me Obe Wan?

    * I got lots of suggestions of what I was doing wrong but it was beyond me to actually make my hands do what I needed. I do now have a coping saw and wooden turning saw.

    ** It was very thickly planed 4/4 birch. This is also what I tried the fret saw on.

    Hi Tony

    Using the Knew Concepts fretsaw should set you up for easy waste removal. I should be claiming some authority here since I have used one longer than any other person, with the exception of the late Lee Marshall, since he and I developed the saw together for woodworkers. If bored, that story is here: http://www.inthewoodshop.com/ToolRev...tsFretsaw.html

    Anyway, I set mine up with the Pegas blades to cut on the pull. You do NOT use these saws to cut on the push. Secondly, you hold the fretsaw the saw way you hold a dovetail saw - very light grip - and you let the teeth do the work Ö. if the blade is bending, you are applying too much force.

    There are two steps to achieve easy waste removal:

    The first is to undercut the baseline and create a chisel wall Ö.



    Only THEN do you use the fretsaw to remove the waste. And you do this leaving about 1mm above the baseline Ö



    This is the result Ö



    If you attempted to add the chisel wall after cutting away the waste, you might struggle to do so since you now lack enough of a sight line. Do the chisel wall first!

    The purpose of the chisel wall is to prevent the chisel being pushed back over the baseline. I mentioned this in your other post (which if you had read, these points would be obvious ).

    When you chop out the waste, the obvious thing is that you need sharp chisels, but this is not enough to prevent crumbling. You must take THIN slices Ö



    If you do all this, I am confident that you will end up with precision dovetails. Someone wrote that good dovetails require practice. I think that is nonsense - I never practice. What I do is apply rules that involve release cuts and secure boundaries. I learned a lot of this from David Charlesworth. Try and get hold of the last two editions of the Quercus magazine, in which I have articles about his heritage.

    EDIT TO ADD: note that you only chop halfway from each side. Also, I work from the non-show side first. This protects the show side from an unfortunate slippage of the chisel blade.

    Lastly, I made a godawful video demonstrating the technique with fretsaw Ö

    https://m.youtube.com/watch?v=M6O4rY_0zQs

    Regards from Perth

    Derek
    Last edited by Derek Cohen; 09-18-2022 at 10:29 PM.

  9. #9
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    I'll suggest that wood species is never the problem. All wood can be sawn and cleaned up with a chisel. Of course some species are easier than others, but proper tooth count on the saw blade and sharpness of the chisel make the task work.

  10. #10
    Quote Originally Posted by David Bassett View Post
    Oh, another thought. I think Derek has an article on his website about making a new handle for a Knew Concepts saw. Maybe a different size or shape would help?
    Here's a web page on making a new handle for the Knew Concepts fret saw.

    I have not had any problems using the Knew Concepts fret saw to saw out dovetail waste.

    Mike
    Go into the world and do well. But more importantly, go into the world and do good.

  11. #11
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    Quote Originally Posted by Mike Henderson View Post
    Here's a web page on making a new handle for the Knew Concepts fret saw.

    I have not had any problems using the Knew Concepts fret saw to saw out dovetail waste.

    Mike
    I'm sorry Mike, that's probably the page I so vaguely remembered. (My excuse is that I've never felt limited by the Knew Concept Saw's handle, just my own lack of skill, so I didn't need to remember your how to rehandle it article.)

  12. #12
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    Iím not sure rehandling is necessary. As far as push vs pull, Iíve tried both directions but started pull and thatís been the predominant attempts.

  13. #13
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    Re-handling is helpful, even important, but not the vital issue in using the Knew Concept fretsaw.

    Here is one of mine with old ones in the background ...



    Here's another I made, influenced by Blue Spruce ...


    Regards from Perth

    Derek

  14. #14
    Non neander method: I use a pin router and a pattern bit. This gives the cleanest, sharpest bottoms with no blow out.

  15. #15
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    I have the Knew saws and tried that. I then watched Paul Sellers and tried that method with chisel only. I ended up liking Paul's method better for now but I often change my mind on what is best for me. At the end of the day it really came down to crisp knife or marking lines and sneaking back to that line with a chisel strike. I am far from perfect but can get away with it.

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