When I first decided to start woodworking, I decided to read as much as possible first. A friend of mine told me that’s nice, but you need to start making sawdust.
I thought his advice was good, but I read a lot anyway. The first woodworking book I bought was “Woodworking Wit and Wisdom” by Jim Tolpin. I can’t stress enough the enormous luck I had in choosing this book for my first real investigation into the serious side of the craft. By “serious” I mean making furniture with woodworking joints, not just picnic tables with deck screws.
Anyway, this is where I first read about pegging tenons and the “drawbore effect”. It is without a doubt the best way to make a mortise-and-tenon joint if your tenons are long enough. The tenons for the frame of this wardrobe are all 1-1/4″ long. Long enough to accept a peg without blowing out the edge of the tenon.
The “drawbore” effect comes when you drill the holes in the tenon. In the picture I already have the holes drilled in the mortised pieces–you drill the holes in the tenons after you have a good fit in the mortise. Some people just drill through a completed mortise-and-tenon joint and insert a peg. This is a good mechanical joint for when the glue eventually fails, or racking stresses are introduced in the joint, but if you offset the hole in the tenon by 1/16″ or so, you then draw the tenon shoulders tight to the leg.
Here’s how it works: You cut your mortises and tenons, then tweak the fit. Drill a hole through the mortise where the center of your tenon will be (5/8″ in from the edge for a 1-1/4″ tenon). You can drill straight through a thin piece-such as a 3/4″ thick door frame, or you can drill a stopped hole; such as in a thicker table leg. After you have your tenon fitted to your mortise, you insert your brad point drill bit into the hole, marking the tenon. Pull out the tenon and drill a hole 1/16″ or so closer to the shoulder than your mark. When you drive your peg, the offset of the holes will pull the tenon shoulders tight to the mortised piece. A very stout joint with a mechanical lock that will stand the test of time.
Next up: How I made the pegs