Simple Tip for Joining Wide Boards

I needed a wide board for a project. Not wanting to cut the piece from a bigger board, I decided to join a couple of pieces lying around. There are commercial jigs or tools to make the joinery, i.e. biscuit joiner or the special Festool Domino, or pocket hole joinery.  If one does not have any of those, a table saw alone will do.

First step is to create a groove on both pieces to be joined. It's critical, of course, that the groove should be perfectly centered at each edge of the boards. The easy way is to use an ordinary saw blade. Set the height to about 3/16 inch. Eye ball the blade to the center of the edge. Run the board one way, then flip it around, so the other flat edge that was away from the fence is now against it. This insures that the groove is perfectly centered. The final groove could be slightly wider but that is fine.

Now, you can rip the rib that will be sandwiched between the the edges. I keep a lot of ripped pieces at the scrap heap and sure enough I found one. I cut it to the right width (3/8 inch), applied glue to the grooves and the rest is normal glue up. 

This is going to be a strong joint without any special jig or tool, other than the table saw.