Mortice lock with or without latch
This type has the lock recessed into the door edge.
They are available in different sizes enabling the handle itself to be located either closer to, or further from, the door edge.
Marking out for the lock
Mark the centre line of the lock edge of the door. Hold the lock flat against the door edge and mark the top and bottom. Now measure the thickness of the lock and mark this symetrically about the centre line. You should now have a rectangle marked on the surface ready for cutting.
Drilling and cutting
Using a drill a little thicker than the lock itself, drill a series of holes within this outline to the appropriate depth into the door. If you do not have a depth gauge on your drill, simply mark the requied depth on the drill bit with chalk.
Now cut around the outline with a sharp chisel and pare out the waste. Do this in stages, each time cutting along the outline first to keep the edges clean. Be careful not to cut too deep at each stage, as the sides will split if the chisel is forced too far into the wood. Use the flat side of the drill against the outside edges of the recess. Using the chamferred side against the edge will cause the chisel to drift off course.
Slide the lock into the recess and mark the perimeter of the face plate. Using a sharp chisel, cut along this outline to a depth equal to that of the plate. Make small cuts across the grain within the outline and pare out the waste with the chisel. Hold the lock back to front and offer only the plate into the recess. If you insert the whole lock at this point, you may find it difficult to remove. Sit the plate into the recess to check that it fits flush with the surface.
Mark the position of the fixing screws and drill pilot holes for them. If the back of the plate is shaped for the screw fixings, use a countersink tool to bore out a recess for these. Hold the lock against the face of the door so that the plate is flush with the door edge. Mark through the key hole of the lock on the horizontal line previously drawn on the door face.
Using a drill bit a little larger than the key hole, drill a set of holes through the door to produce the opening at this mark. Take care as you reach the far side, as excessive pressure on the drill will cause the other face to split. Keep the drill square and level or the key will not easily fit into the lock.
Use a padsaw to trim these drill holes into a slot to accommodate the key.
Clear out all the debris from the work using the crevice tool on a vacuum cleaner.
Fitting the lock
Push the lock into its housing and ensure that it lines up with the keyhole before fixing in place with the screws.
Position the key hole covers on both faces and check the operation of the key in the lock.
Lock and latch
With the lock and latch type, a hole must also be drilled for the spindle before inserting the lock and the handles fitted as for a mortice latch