When this lock was acquired, the case and bolts were in a dirty, deteriorated condition. The movements were completely unserviceable. In addition these were of a later date (1950-1960) than the case, that being c. 1900-1920. All of the screws and bolts were corroded the rest of the lock needing a complete cleaning. To get the bolts back to their original blued condition, they had to be re-surfaced to remove the corrosion, polished and then heated to regain their original blued steel color.

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                                Diebold 3 mvt restoration.JPG (875324 bytes)

                                Diebold 3 mvt restoration (1).JPG (858090 bytes)

Diebold 3 mvt restoration (2).JPG (831652 bytes) Diebold 3 mvt restoration (3).JPG (836392 bytes)

A heat gun makes for a good, controlled heat source for small, compact parts like screws. Once the part is brought up to temperature, the right color is achieved. This happens in a very brief period of time - a second or two. The part is then quickly quenched in water to hold the color. Later I smear some light oil over the part to prevent corrosion.

Diebold 3 mvt restoration (4).JPG (769122 bytes) Diebold 3 mvt restoration (5).JPG (676008 bytes)

Here a comparison between a bolt as found complete with corrosion and chewed up slot from the sloppy use of a mis-sized screw driver. The bolt must be resurfaced to remove corrosion, the slot dressed and then polished to prepare the surface before heat treatment to get the blue color.

Diebold 3 mvt restoration (6).JPG (813820 bytes) Diebold 3 mvt restoration (7).JPG (888650 bytes)

Time locks are precision instruments. They had to be both accurate and reliable. Failure meant that the safe could not be opened and much expense, time and embarrassment would ensue.  These last two photos shows the typical way that these locks were manufactured. Most if not all parts were serial numbered and assembled as an individual entity. mass production, while wide spread at the time, was not used in this industry until much later in the the 20th century.

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