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Countersinking holes on the face of a faceplate?

Discussion in 'Newbie' started by Jesse Tutterrow, Jan 2, 2018.

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  1. Jesse Tutterrow

    Jesse Tutterrow

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    Saint Louis, Missouri, USA
    Although new to woodturning I have done flat / box woodworking for many years and I know that when you drive a screw into a piece of wood the wood will mushroom up around the hole. Some woodturning DVDs and videos advise adding a countersink to the front (wood) face of a faceplate to provide a clearance space for this mushroom affect.

    Is this advisable?
    If so would the countersinks change the balance of the faceplate?

    Thanks in Advance
     
  2. hockenbery

    hockenbery AAW Advisor Staff Member

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    I use a faceplate for most of my hollow forms. These are green wood.
    I just drive screws into the wood no pilot hole or countersink.
    My faceplates are flat across with not countersink some faceplate are manufactured with a countersink.
    What I do in prep is turn a slight concave in the wood so that the edge of the faceplate makes solid contact with the wood with no wobble. Draw a few pencils circles to center the faceplate.
    This is a 1/16 to 1/8 gap where the concave is and that leaves a tiny bit of room for wood pulled from the screw hole.
    I make the area where a screw the faceplate an inch larger in diameter than the faceplate timrpevent any splitting and a 1/4 taller than the screws depth because the screws open a hole in front of themselves as they seat.

    After the piece is mounted I cut the mounting area close to faceplate diameter to allow more turning on the forms surface.

    Lyle Jamieson has two excellent videos on making glue joints in which two concave areas face each other so that the glue is on the outer edge of the matting surfaces. A concave on the bowl blank worked great for a faceplate. in the video he has lots of room for screws before he turns it away.


    View: https://m.youtube.com/watch?v=rbZXEBIHVOU

    In the rare event I put a faceplate on dry wood I drill pilot holes.
     
    Last edited: Jan 2, 2018
  3. Jesse Tutterrow

    Jesse Tutterrow

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    I didn't even think about specifying the wood I would be using. It would be dry wood from a board.
     
  4. Bill Boehme

    Bill Boehme Administrator Staff Member

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    I understand your concern and especially on plywood or MDF I usually first predrill holes and then use a countersink bit to create a chamfer. On a few aluminum faceplates I have also chamfered the back side of the holes. I normally don't go to all of this extra effort unless I am making a special fixture or vacuum chuck where the faceplate becomes a permanent part, for example, the vacuum chuck pictured here where the faceplate is attached to MDF.

    image.jpeg
     
    hockenbery likes this.
  5. Hy Tran

    Hy Tran

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    I typically drill a small pilot hole, a little smaller than the root diameter of the screw into my blank (but I almost exclusively work with kiln-dried or air-dried wood; in New Mexico, green wood air dries really fast). This is not to prevent mushrooming--but because it's easier for the screw to tap a thread in the wood, and the screw follows the pilot drill hole better. (My skills with a hand-held cordless drill/driver are less than optimal). When I drive the screw into the blank, I do the "wheel nut" method. For a 4-hole faceplate, 12 o'clock, 6 o'clock, 3 o'clock, 9 o'clock.

    Unless you are particularly good with hand tools, or have access to a machine shop, I would not suggest countersinking the faceplate side of the faceplate (but that's just my hand-eye coordination speaking). I wouldn't worry about the balance of the faceplate--you'd be removing the same amount of material from each hole, at an equal (and radially symmetrical) distance from the axis.

    A safety notice: I have never broken a screw in a faceplate, but I have had a blank rip out of the screws. This was an older piece of wood that was pre-turned (by someone else). I rescrewed into different, clean locations on the wood, but it turns out with diagnosis that the wood was a bit spalty. So, in addition to the usual cautions about using good screws and having a flat surface to mate into: Make sure you have sound wood, and don't overdrive the screw (where your screw turns into an inexpensive routing bit).
     
  6. john lucas

    john lucas

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    I counter sunk the holes on all of my faceplates. Only took a few minutes and simply takes the worry out of that problem. It would be hard to change the balance since your not removing but a fraction of weight. I used a drill press and just did it by eye. Then if I make a piece flat instead of concave I don't have to worry about pulling the fibers up as I screw things on.
     
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  7. Tom Albrecht

    Tom Albrecht

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    Yep, countersink all the holes on the face of the faceplates. Your faceplate ballance won't be thrown off. I am probably not the only one here who learned it from experience and David Ellsworth.
     
  8. john lucas

    john lucas

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    I think I learned it from Clay Foster.
     

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