I recently completed a large wall cabinet using Somerfeld's offset tongue and groove system and found it resulted in extremely square and strong joinery. I like that you can elect to have a scribe edge remain on the cabinet sides by reversing the bit or have the ends meet even with no lipped edge. All parts (back panel, bottom, sides and nail rails) lock together solidly. His system does seem to require using face frame designs, but I may be wrong on that. I found interchanging the two bits on the router table easy with no adjustment to height . . . just swap them out with each other.
Originally Posted by Ron Roase
Treasure Island FL