Sanding Convex and Concave Curves

Figure 19-22. Use the worktable extension when sanding a concave curve.

As mentioned in the beginning of this chapter, you aren't limited to sanding just flat, straight surfaces; the belt sander will also sand curves.

The belt sander will quickly remove millmarks from curved workpieces. Or, when the shape of a curve is critical to the design or fit of a workpiece, many woodworkers cut wide of the mark and use the belt sander to sand the stock to its final shape. This technique gives you better control and accuracy when making oddshaped workpieces.

To sand both convex and concave curves, secure the belt sander in the horizontal position. Install the worktable parallel to and no farther than 1/16" above the belt. If you haven't already done so, make the worktable extension shown in Figure 19-25; then bolt it to the worktable. This extension is essential when sanding both concave (Figure 19-22) and convex curves.

To sand convex curves, hold the workpiece firmly against the worktable and rock it against the direction of rotation on the hard side of the belt sander. Sand the curved edge evenly until all millmarks are removed and you achieve the desired shape. To sand concave curves, hold the workpiece firmly against the worktable and roll it against the direction of rotation on the idler drum. Once again, sand the curved edges evenly until all millmarks are removed and you achieve the desired shape.

When sanding with the idler drum, use very light pressure. If you press too hard, you'll put an unnecessary strain on the sleeve bearings in the idler drum. You may also ruin the crown of the abrasive belt. Once the crown is destroyed, the belt will not track properly.

Continue to Sanding Compound Curves and Odd Shapes
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