Video: How To Make Tongue & Groove V-Groove Boards
V-groove board is a decorative panel board similar to beadboard. It features chamfered edges that form a v-groove between each board. The v-groove creates a nice shadow line. You can purchase special router bit sets that will cut the tongue and groove joint and the v-groove in a single pass on each board, but you can also make these boards using more common router bits.
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Video: How To Make Tongue & Groove V-Groove Boards - Video Transcript
Speaker 1: Whenever you're making tongue and groove joints, the general practice is to start with the groove and then cut a tongue to fit the groove. If you'd like to make these slats on your router table I suggest you use a slot cutter for cutting the groove. Mine has an eighth-inch wide cutter on it and I've installed an oversized bearing to give my cutter about a quarter inch of exposure. Raise a bit so the cutter will hit the center of your slat thickness. On this project, the slats are three-quarters of an inch thick. Then set the fence so the bit projects out from the fence a quarter inch or so it lines up with the rim of the bearing then cut the groove. It's a good idea to mount a feathered board to both your router table and to the fence so workpieces are kept snug to the table and to the fence during the cuts.
Now that you've got the grooves cut on the edge of your slats you're all set to cut the tongues and for that, any number of standard bits can do the trick. All you need is a bit that can cut a square profile on the edge of the workpiece and for that, you could use a rabbeting bit, a spiral bit, a conventional straight bit or even a slot cutter again. What we'll do is set up the bit to cut the cheek and the shoulder of the tongue in one pass and in two passes the tongues will be done.
For an example, we'll use a standard three-quarter inch straight bit here. Bury the bit in the fence so just a quarter inch of the cutter projects out and raise it until the top of the bit just kisses the groove. Cut this shoulder and cheek on all the slats then flip the workpieces in far end and cut the second shoulder and cheek adjusting the cutting height if necessary.
When you're making these tongue cuts it's a good idea to start on test pieces first so you can get a good fit of the tongue in the groove and what you're going for is an easy friction fit between the parts because remember the slats are going to expand and contract with changes in the humidity. You want the tongues to be able to move in the grooves. With the tongues and grooves cut, all you have left are the chamfers along the front edges of the slats. It would seem like the most logical bit to use would be a pilot and chamfering bit. The problem is the bearing gets in the way of the tongue. It won't work. Instead what we're going to use is a V-bit.
They're very common bits and often they're packaged in group router bit sets. It'll fit underneath on the tongue side as well as cut the chamfer on the groove side just fine. Set up your V-bit so the pointed tip of the bit is positioned just inside of the fence facings on your router table fence. Raise or lower the bit as needed to cut the amount of chamfer you like but set the bit slightly lower than the tongue height. Once dialed in you're ready to cut the chamfer on the groove side of the slats but not the tongue side. Make those profiles now in single passes through the bit.
Now you're ready to cut the chamfer on the tongue side of the slats but for that, you'll have to make a setup change to the router table fence first. With the tongue touching the fence push the fence away from the V-bit to set the chamfer cut. Lock the fence and make a test cut to check your results. Make sure to cut with the tongue edge pointing toward the fence and cutting on the front edge of the bit like this not on the back ends, that would lead to a potentially dangerous climb cutting situation.