Fluting in flat surfaces adds grace to fireplace surrounds, doorway casings and the like. This router jig simplifies the process.

Start by building a guide carriage with two parts: a fixed base that attaches to the router and a movable base that straddles the workpiece. I used 3/8-in.-thick Baltic-birch plywood, but any similar dense material will do. It is possible to fasten the two parts of the jig together with wing nuts and slots. But because there are usually only two settings, I screw the two parts together with six wood screws.

Tradition dictates four or five flutes. I like to use four flutes because I can get the maximum effect with the minimum of router settings. Either way, lay out the profile of your flutes on a piece of paper to determine the spacing of the flutes (the layout shows you the settings for the jig). Remember that you will be making identical cuts from both edges of the workpiece, so only two settings will yield four flutes. Draw index marks on the fixed base to show where you will attach the movable base. Get the feel of your jig by making practice runs on a scrap cutoff. Take note of the following:

¥ The movable base must straddle the stock so that it slides freely but with minimal slop in the fit. This requires the stock to be perfectly uniform in width.

¥ Use new or freshly sharpened core-box bits. Dull bits are hard to push and leave burn marks.

¥ Check the spacing of the flutes with only two of the six base screws in place. Adjust the settings of the movable base if necessary. When the spacing is perfect, screw the movable base to the fixed base with all six screws.

¥ Use a variable-speed router, if possible, and slow the speed at either end of the flute.

¥ Draw the router to you. Make several passes, and finish with a fine cut.

¥ Use a good respirator mask and a pair of goggles.

William D. Lego, Rockford, Ill.

Fine Woodworking Magazine, February 1995 No. 110

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