The Technique of FURNITURE MAKING
DOWELLED EDGE JOINTS
These are no longer used to any great extent but handworkers may find the process useful, particularly where the jointing methods must be hidden. The boards are planed slightly hollow
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152 Setting/laying out dowel positions |
and a marking-gauge is run down the centre of each edge; the boards are then cramped/ clamped together and the dowel positions squared across. Boring must be dead accurate with a3/8 in (9.5 mm) dowel at about 5 in (125 mm) centres for up to 1 in (25 mm) boards, and1/2 in (12.5 mm) dowels for thicker timbers. It is usually reckoned that dowel-pegs should enter about 11/4 in (32 mm) for maximum efficiency, with a slight gap at the bottom of the socket for surplus glue, with the dowel driven home on one edge and the projection checked with the corresponding socket on the other edge. The dowel ends can be chamfered and the sockets countersunk for easy entry, particularly
if there are slight errors in the laying out. Where boards have to be end butted to increase the overall length, dowels offer a practical method of strengthening the joint.
ASSEMBLING DOWELLED WORK
One side of the work should be dowelled, the pegs tapped fully home, surplus glue wiped off and the projection of each peg checked with its corresponding socket; it can then be dowelled into the other member without waiting for the glue to harden. If a trial assembly is made in the dry (unglued) state, spare dowels should be sanded to a loose fit and replaced with tight dowels in the final gluing up, for if tight dowels are used it may prove impossible to withdraw them without breaking the pegs. For assembly, single-application glues (hide, Cascamite One Shot, etc.) should be used and applied to the sockets only, for very liquid glues or separate hardeners applied to the pegs may swell the fibres and prevent entry. Sockets out of line or bored at an angle should be filled with glued pegs and rebored correctly, for any bending or crushing of the dowel-pegs will destroy much of the ultimate strength. Woods which split easily may have to be nipped with a G-cramp/C-clamp across the thickness if the dowel is tight and the surplus glue cannot readily escape. Sash-cramps across the assembly may be necessary to pull the dowels up.
