
Sargent
& Greenleaf, model #4 version 2. c. 1884, restoration page 2.
Below and next page are depicted several steps necessary in the restoration of
a time lock. The first is complete disassembly and cataloging of parts. Separate
containers are used for grouping parts in a logical sequence. Digital photography makes
documentation easy and cheap. Parts are cleaned in various sized ultrasonic machines
according to part size. Total parts count 184.

One must be careful to know when a part may not be put into a cleaning
solution. Below is a rear shot of one of the porcelain dials denoted in original wax
marking. Proper preservation requires this to not be lost as would be the case if the part
were put into an ultrasonic cleaning procedure. Notice how badly gunked the parts were,
even the delicate balance springs.

As with nearly all parts on early time locks none are interchangeable. One must
be certain that pivot jewels are logged in their proper locations; upper lower plate as
well as each wheel. On this lock each jewel pivot has a small punch mark to locate the
rotational position of each in it's respective hole. Later locks dispensed with this
as manufacturing techniques became more precise. A computer at the bench helps in
documentation of parts and reassembly.

Heat bluing of parts is a particularly enjoyable part of the process for me. It
is partly an art to be able to get just the right color as the metal turns from straw to
purple to electric blue, and then a dull pale blue in matter of seconds. Surface
preparation is crucial, a fine finish as well as no contamination (oil or dirt) is
essential for a beautiful even color. Larger parts like the dial hands require an
additional skill at making sure the entire part is heated to the proper temperature at the
same time to get a uniform color throughout the part. When desired color is achieved the
part must be immediately quenched to stop the color change. I use water, others use oil.
However, oil tends to darken the color so one must compensate for this when heating. If
the part is over-heated and the wrong color is present, the entire refinishing process
must be done again. Below are shots of the dial hands. These were given a fine grain as
was originally rather than the standard polish given all of the screws.


