|Medicine cabinet: Shutters are invariably made with mortise and tenon joinery|
Drawbore: noun (Joinery) A hole bored through a tenon nearer to the shoulder than the holes through the cheeks are to the edge or abutment against which the shoulder is to rest, so that a pin or bolt, when driven into it, will draw these parts together. [The Free Dictionary]
Cabinet shutters experience a lot of use during their lifetimes which means poorly constructed ones can come apart or loosen much before the cabinet shows any sign of wear. This is why traditional cabinet makers preferred the strong mortise and tenon joint to put together shutters.
Although modern adhesives ensure that the mortise and tenon joint will be strong and long lasting, it is always better to further reinforce the joint with the use of drawbore pegs. This ensures a tight and super strong fit that will endure seasons and years of usage without the slightest stress.
In India because of the high humidity and heat, traditional cabinet makers continue to drawbore their mortise and tenon joints.
|Diagram: How Drawboring works|
Drawboring is a simple process that requires pegs to be driven through holes drilled separately through the mortise and tenon joint. The hole drilled through the tenon needs to be offset by a small amount so that when the peg is driven through it pulls the tenon tighter into the mortise. (see diagram)
I avoided drawboring in the past because I anticipated problems in making round pegs. I thought I needed a dowelling plate or some jig to make perfectly round pegs until I read that it was not necessary to have perfectly round pegs.
|Pegs can be whittled with any knife|
I tried my hand at whittling pegs and found it easy. Once they are driven in, sawed off and sanded flush, they look perfect.
|Drawbore Pegs sawed and sanded flush|
A drawbore pin made by Sunil Chetiwal came in handy; this tool, which is very much like an awl with a long shaft, helps in pulling the tenon into the mortise after which the peg can be hammered in easily.
|Chetiwal's Drawbore Pin|
From now on I plan to drawbore all my mortise and tenon joints, especially because I know how easy it is to take this extra step to make super strong joints.
For more information read "Drawboring Resurrected" by Christopher Schwarz at http://www.popularwoodworking.com/techniques/joinery/drawboring-resurrected
19 April 2015