Headstock veneer

Discussion in 'Guitar Building' started by Vernon805, Feb 25, 2016.

  1. Vernon805

    Vernon805 New Member

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    I read in the Benedetto book that veneer on only one side of the headstock is more suseptable to warping than veneering both sides.

    Anyone have experience with this?
     
  2. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    As a general rule, if you apply veneer to a porous material such as maple or mahogany, it acts as a moisture barrier to the face upon which it has been applied. Unless there is a similar barrier on the back side of the piece, it will be able to absorb moisture and expand (causing a concave warp at the face) or release moisture to a dry environment and shrink (causing a convex warp on the face). This can range from barely measurable to really distracting, depending on the material and a bunch of other variables.

    For instance, I have a series of paintings in my office by my daughter, who painted with acrylic paint and gold leaf on masonite. She first applied acrylic gesso, a vapor barrier, to both front and back but used only one coat. The paint is a very effective vapor barrier on the front and the gesso only a moderately effective barrier. It requires multiple coats to be really effective. Masonite is not structurally robust and so will not resist warping. The paintings are 1' x 2', which provides a lot of area.

    They warp visibly a little differently every day - are clearly breathing moisture without much resistance. To stabilize them will probably require mounting on a plywood board frame. That illustrates the idea.

    Veneer on one side of a headstock, without more, will certainly tend to make it warp. But many (perhaps most) guitars are made like that and do not show warping. Why is that? They are structurally robust, and they almost certainly have effective vapor barriers applied to the back as well- lacquer or poly finishes, for instance. By inhibiting the passage of water vapor, you can be sure the piece will remain stable.
     
    pshupe likes this.

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