the edge rabbet is for the skids to sit in, allowing small movement from swelling/shrinking without pulling out from under the skid strip, the outside edge boards don't get any shaping where they mate with the flat flange of the box side

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics