How do I hide the bottom slot in a box-jointed box?

How can I rout a groove to accept the bottom panel in a small box-jointed box without exposing the unsightly groove on the outside of the box?
—Mike Lockhart, Southfield, Mich.

There's a simple solution, Mike: Use a box-slotting bit (above). These bearing-guided bits, sold in multiple sizes, cut a groove for precisely this purpose in small boxes and drawers. Some bits even come with different-size bearings to change the groove depth.

Here's how to use one: After cutting your joinery, dry-assemble the box. Make sure the top and bottom edges are flush. Clamp the box as shown; then use a box-slotting bit to rout the groove around the box interior, keeping the box pressed against the bearing. Note: Because you're routing on the inside of the box, make sure you feed the box clockwise around the bit. Finally, cut the bottom panel to fit, radiusing the corners to match the bit's radius.