Making sawdust in MS
Join Date: Nov 2011
Location: Philadelphia, Ms
The dowels can go all the way through if that's the look you want. On mine I only drilled through the bottom. The tongue was on the table, the groove was on the breadboard. I drilled the holes in the breadboard with it off the table, like I said, through the bottom part. Using those holes I marked with a pencil the location of those holes on to the tongue. Then I drilled the holes in the tongue about 1/16 closer to the table. That way when you tap the dowels in, it pulls the breadboard in close and holds it tight. Before I put the breadboard on, I elongated the outside holes so the top can move side to side. I only glued the center dowel all the way through. The others I just glued the top part that ended on the face of the breadboard. Hopefully I've explained it good and haven't confused you. There are videos on youtube that show what I'm speaking of.
As far as the top, you can glue the boards with dowels or biscuits, I glued mine without any. The modern glues are strong and will hold the top together if the joints are straight and square. Tongue and groove will also work. It is up to you. I hope I've helped and not confused.