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Today's woodworking tasks begin with forming our lips. No, this is not a African tribal rite of passage, it is how we form the ledge or lip of the cutting board to sit on the rim of the sink so it doesn't fall into the sink.
 We start by rounding over the upper edge all the way around the board. The round over bit has a pilot bearing at it's tip that will ride against the edge of the board and self-steer the bit to produce a consistent depth of cut, and thus, smooth edges. So this is not especially tricky.
The next step is a bit trickier. For thus cut we exchange the round-over bit for a bowl-making bit. This bit has no pilot bearing because it's intended to be used to hollow out a piece of wood and make a depression. I don't think I could actually make a bowl with one of these, maybe a tray, but then I didn't name the thing.
 To accomplish our task we will use the router table fence to guide the edge of the board and set the depth of cut. It will take multiple passes to work up the to final depth of 3/4" from the edge, so I first set the final depth.
 I lock down both ends of the fence then slide up a special stop block that rides in the slot at the right hand end of the fence. This snugs up behind the fence mounting bracket and I lock it in place. Now I know when to quit cutting. Leaving the hold down knob at the left end of the fence locked I loosen the one on the right and pivot that end forward, away from the stop block and set the fence to produce a 1/4" depth cut. After I complete the first pass around the board I will loosen the left hold-down and pivot the fence back a little to produce a deeper cut and make another pass. I'll repeat this until the fence is again sitting against the depth stop block; then I'm done.
The straight sides are simple, but the corners need a little extra attention to get them right. Essentially the corners are why we need templates to be made. If all sinks had square corners, or at least corners of the same radius I could simply say, "Send me the width and depth of the board you want." and I could whip it up. But corners vary vastly from sink to sink. The two I'm making now are an example. Charlotte's has very tight corners, John's has large sweeping corners; neither profile would come close to fitting the other sink.
 To get a smooth curvature around the corner I use the two edges of the fence opening as my guide points. This adds the extra utility of allowing me to produce almost parabolic curves for boards like John's where the corner shape is not a simple, consistent radius. By increasing the size of the opening in the fence, the corner of the board pokes into the opening as I turn the corner, thus flattening the curve (increasing it's central radius as opposed to the radius at the ends of the curve. This way I make sure the part of the board that will sit inside the sink opening will clear the corners without having to produce the parabolic curve on the upper part of the board itself. Parabolic curves are very difficult to draw properly without a template designed for the purpose.
 When I think I've got it right and am content with the smoothness of the under-side shape I flip the board over and try the template (also upside down) to see how I did. This one is spot on. I love it when that happens!
When routing on both boards is complete it is time to turn to the construction sanding. Earlier I did some sanding with a 60 grit disk, but just to fair out any ridge that may have been left by the final glue-up. Now we do some serious sanding with 100 grit paper to remove any milling marks, scuff marks, pencil marks, and minor dings.
 I will use the wide belt sander and a 100 grit belt to make quick work of the large flat surfaces, but the edges and edge profiles will need to be done by hand. To make sure I don't change the shape of the under-side of the lip I mill a sanding block from some scrap wood and round over one corner to match the radius of the cove under the lip. This sanding block will allow me to sand the curve and both flats at the same time.
 Once all this sanding is done I bounce a strong light off the surfaces held at an angle to my line of sight and check to be sure I didn't miss any small cross-grain scratches. If I find any, I touch them up and repeat until the surface is free of blemishes.
That completes the construction phase of this project. It is time to flip the switch in the computer to let the web site know that we're proceeding to the finishing stage and get out the finer grits, 120, 150, 180 and 220, we'll need for finish sanding.
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