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Thread: Chasing my tail on a long edge joint

  1. #1
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    Chasing my tail on a long edge joint

    Still working on the 7í table top. Planing the edges of the last panel to put on the edge. Both edges seem plat along their length to my long veritas straight edge and square side to side with my small square. When I put them together there is a gap on both sides full length that doesnít want to close up. I even tried match planing them to no avail. Thoughts?

    IMG_3047.jpg

  2. #2
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    Most of the times I get a gaposis...I check right at the ends...right where the jointer plane starts it's cuts...
    A Planer? I'm the Planer, and this is what I use

  3. #3
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    Does the top panel pivot at the middle?

    I'd take a smoother with a straight edge and set very fine and I'd take a shaving in the middle and test.

  4. #4
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    Quote Originally Posted by steven c newman View Post
    Most of the times I get a gaposis...I check right at the ends...right where the jointer plane starts it's cuts...
    First places I checked, one end is the largest gap, the other consistent with the rest.

  5. #5
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    Quote Originally Posted by Rafael Herrera View Post
    Does the top panel pivot at the middle?

    I'd take a smoother with a straight edge and set very fine and I'd take a shaving in the middle and test.
    Didnít try that with the two panels together. Theyíre too heavy and long for me alone to do that. If I get help I might be able to try that. My 50Ē straightedge doesnít pivot in either board anywhere.

  6. #6
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    Are the gaps the same on both faces? Sometimes that can help chase down slightly out-of-square spots if the joint is slightly open on one face but closed on the other side. If you think it's an issue with flatness along the length, sometimes it's best to start over by making a distinct low spot in the middle (so you know the ends are high) and then taking the ends down so you're just touching the middle again with the plane. You might even leave a bit of a spring in the joint if it pulls together nicely.

    And if all else fails, find a friend with a nice jointer Long edge joints can be tough.

  7. #7
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    Quote Originally Posted by Daniel Culotta View Post
    Are the gaps the same on both faces? Sometimes that can help chase down slightly out-of-square spots if the joint is slightly open on one face but closed on the other side. If you think it's an issue with flatness along the length, sometimes it's best to start over by making a distinct low spot in the middle (so you know the ends are high) and then taking the ends down so you're just touching the middle again with the plane. You might even leave a bit of a spring in the joint if it pulls together nicely.

    And if all else fails, find a friend with a nice jointer Long edge joints can be tough.
    unfortunately it is both sides. I thought if I did the match plane thing I might overcome it if it was a side to side straightness issue but not so far.

  8. #8
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    Quote Originally Posted by Tony Wilkins View Post
    unfortunately it is both sides. I thought if I did the match plane thing I might overcome it if it was a side to side straightness issue but not so far.
    I am confused Tony, my impression is your stock is much thicker than an inch.

    Match planing is a method whereby two thin boards (typically less than 1″ thick each) are placed face-to-face and their mating edges are planed simultaneously.
    This method sounds great in theory. One problem is if there is a bump or dip anywhere along the plane's path, the error will be doubled on the finished pieces.

    Where light shows through a joint are low spots. These do not need any further planing.

    Where no light shows through is a high spot. Mark these areas and using a smoother set fine bring these areas down. Do not plane past the bump.

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

  9. #9
    You could cheat by rubbing the boards together to burnish the high spots,
    you could get a 2 meter fairly nice dual milled spirit level, and get some artist graphite sticks, like large allenkeys, one will last years,
    to highlight the technique further.
    Or make a suitable rigid enough straight edge (x2 for the "three plate method", to double the error, one can get great accuracy doing so)
    and when done with that, get an old style long reach angle poise lamp with at least 7.5" shade, Ikea do them for cheap, "Tertial" type, on my side of the pond,
    I've got a sliding block what rides on the back of the bench, to mount it to, what's a much less fancy thing than Cosmans, but works the same.
    These lamps will fight you if you try to mount them higher, and they need be easily movable to get along with them,
    but nothing compares to them IMO.

    Tom

  10. #10
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    Quote Originally Posted by Jim Koepke View Post
    I am confused Tony, my impression is your stock is much thicker than an inch.



    This method sounds great in theory. One problem is if there is a bump or dip anywhere along the plane's path, the error will be doubled on the finished pieces.

    Where light shows through a joint are low spots. These do not need any further planing.

    Where no light shows through is a high spot. Mark these areas and using a smoother set fine bring these areas down. Do not plane past the bump.

    jtk
    The boards are just over an inch each. The two boards together are just about the most a #7 can handle. Concerning light, my problem is that I canít find a place where there isnít light coming through. I know there must be a high spot somewhere because I didnít get the antigravity lumber. I might have to go back and create a definite hollow as suggested earlier unless yíall can suggest something different. Re match planing: hadnít been doing it but tried it to see if corrected an out of kilter plane side to side. The boards are high enough in the bench that itís been throwing off my natural planing square.

  11. #11
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    The boards are just over an inch each. The two boards together are just about the most a #7 can handle. Concerning light, my problem is that I can’t find a place where there isn’t light coming through.
    Is your blade cambered?

    That is one possible way to allow light through over the full length.

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

  12. #12
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    Quote Originally Posted by Jim Koepke View Post
    Is your blade cambered?

    That is one possible way to allow light through over the full length.

    jtk
    My blade is cambered. I have a straight blade for my 5 1/2 and keep my BU jack straight; I could use one of these to see if it fixes it?

  13. #13
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    Quote Originally Posted by Tony Wilkins View Post
    The boards are just over an inch each. The two boards together are just about the most a #7 can handle. Concerning light, my problem is that I canít find a place where there isnít light coming through. I know there must be a high spot somewhere because I didnít get the antigravity lumber. I might have to go back and create a definite hollow as suggested earlier unless yíall can suggest something different. Re match planing: hadnít been doing it but tried it to see if corrected an out of kilter plane side to side. The boards are high enough in the bench that itís been throwing off my natural planing square.
    When you say that there is a gap at each end, do you see a gap for the width of the board or a gap either the front or back of the joint (that is, the edge is not square)?

    If the answer is yes to the 1st question, then you're shaving a bit much as you start and end the plane pass. In other words, you have a convex edge. You could try to start the plane one or two inches into the board edge and stop cutting one or two inches before the end of the edge.

    If you're boards are 1" each and your #7 is cambered, I wouldn't plane them together. Is it a minuscule camber or a significant one?

    Even though it may be difficult to mount one board on top of the other, that's the best way to check and fit the joint. Mount one of the boards on the vise so the edge is at or above the level of your bench top, clear the bench top and lay the other board there. Flipping it an placing it over the other board should be a little easier.

  14. #14
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    Quote Originally Posted by Rafael Herrera View Post
    When you say that there is a gap at each end, do you see a gap for the width of the board or a gap either the front or back of the joint (that is, the edge is not square)?

    If the answer is yes to the 1st question, then you're shaving a bit much as you start and end the plane pass. In other words, you have a convex edge. You could try to start the plane one or two inches into the board edge and stop cutting one or two inches before the end of the edge.

    If you're boards are 1" each and your #7 is cambered, I wouldn't plane them together. Is it a minuscule camber or a significant one?

    Even though it may be difficult to mount one board on top of the other, that's the best way to check and fit the joint. Mount one of the boards on the vise so the edge is at or above the level of your bench top, clear the bench top and lay the other board there. Flipping it a placing it over the other board should be a little easier.
    Itís strange, the gap seems consistent from one end to the other and on both sides. Itís a fairly minuscule camber but not none. I only tried match planing because I couldnít figure anything else out. The way you described testing fit is the way Iíve been doing it. Wears me out but the only way to do it that Iíve found.

  15. #15
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    It's hard to tell but are the boards surfaced both sides to the same thickness
    The significant problems we encounter cannot be solved at the same level of thinking we were at when we created them.

    The penalty for inaccuracy is more work

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