The Telephone on P. E. I. - Ultrasonic Cleaning of Dials?
Yes, Virginia, it is possible to successfully clean sticky dials using an Ultrasonic Cleaner....
** Follow these procedures at your own risk! **
Some time ago, I found myself wondering if it would be possible to successfully clean old sticky dials with my ultrasonic cleaner. Dials are often gummed up by incorrect lubrication and cumulative dust collection over the years resulting in a stuck, erratic, or slow moving dial. Some times, necessity is the mother of invention. What is the best way to clean them?
Well, some people suggest a cleaning with solvent. To do this properly, this often requires a major dissassembly of the dial, and can result in a residue being left which will further encourage the collection of dust. The major objective is to remove old buildups of dust and oils - these are the major cause of sticky dials. Many simply douse the dial with products such as WD-40 - not a good idea, as WD-40 is a water displacing solution with a high content of kerosene. It will free up the dial, but only for a while. Over time, a dial treated in this manner will collect even more dust, adding to the original problem.
The solution is to completely clean the dial, and to avoid, if possible, the use of any lubricant.
Now, in January/February 2005 I asked the members of the telephone email list I belong to whether any of them had tried ultrasonic cleaning. None who replied had, a few had thought of doing so, and some who told me it wouldn't be successful unless a very high power cleaner was used.
Those who said it wouldn't work were wrong. My ultrasonic cleaner, though sold under a different brand name, is the same as the inexpensive Nexxtech cleaner that "Radio Shack" sells. As an experiment I tried a couple of very sticky dials I had here in the ultrasonic cleaner. The results were outstanding! Not only did the cleaning clean the dial cosmetically, but the cleaner removed old oils, varnishes, and dust from the dials, even from areas which would have been inaccessable for cleaning by other methods without major dissassembly. After rinsing and drying, without any additional lubrication, the dials worked effortlessly and smoothly.
How was this done? I used a watch cleaning solution called "L&R #111 Ultrasonic Ammoniated Watch Cleaning Solution" obtained from a jeweller's supply house. This solution is specially formulated for safe ultrasonic cleaning of watches. As a dial is basically a clockwork mechanism, I felt this would be excellent for the job, as it proved to be. It does not appear to affect plastic parts in any dials I have tried so far, but I only tried it with dials having no thermoplastic surround (i.e. I haven't tried it yet with 500 set dials). No matter what solution you use, always try a small amount on an unobtrusive portion of any plastic dial surround first, or remove any surround before cleaning if worried about possible discolouration - this may be necessary anyway depending upon the size of the tank in your cleaner. This solution may be ordered from a number of places, "Twin City Supplies in Minneapolis", and "Alpha Watchmaker Tools" here in Canada. Other suitable solutions might be found by searching Google for "Watch Cleaning Solutions". There is also a waterless version of the cleaner, but it is difficult to rinse, and I find this one works just as well. I have since tried cleaning a dial with only warm water and a bit of Sunlight liquid dish soap - it also works, but the dial isn't quite as squeaky clean as the watch solution gets them. However, functionally, it turned out just as well, old oil deposits and dust gone.
To use it, fill your ultrasonic cleaner to a level which will accommodate the dial. Do not fill above the maximum fill line. Remove the dial number ring and card or fingerwheel and card on newer dials. Place the dial in the ultrasonic cleaner. Close the lid, and turn on the cleaner. Mine has three minute cycles. On a typical dial, two three minute cycles is enough. Turn the dial over between cycles. Use as many cycles as a visual inspection of the dial deems necessary. On one particularly dirty dial, I used four cycles, and the amount of dirt removed was incredible, the cleaning solution brown with dirt when it was done.
Once the active cleaning is complete, rinse the dial in warm water, then place the dial over a warm air vent to dry for several hours. Ensure that the dial is thoroughly dry before testing - any water left in the governor will slow the dial until it has evaporated.
If further lubrication is necessary, use only a silicone or teflon/fluon lubricant applied sparingly with a precision pen oiler to the gears, pawls, and pivots. Do not lubricate the dial governor. The reason I mention the type of lubricant, is a standard oil should never be used on a dial, and excessive amounts should never be used, as this will encourage the collection of dust, and varnishes will form as the oils dry. A good example of a suitable oil is "Moebius 941 / 2 Synthetic Watch Oil", an oil also recommended by several camera repair sites for lubricating shutters in cameras, another application where dust collection is a no-no. Another good candidate is Radio Shack's "Precision oiler with TeflonŽ", a teflon/fluon mix complete with a precision pen-oiler. Both the above-mentioned lubricants are advertised to resist dust collection. In the case of the dials I tested, no lubricant was necessary, even with the really dirty one - after cleaning it performed effortlessly without the need for any lubrication. I must point out that Northern/Western Electric dials received no lubrication from the factory from what I have been told, nor was it deemed necessary. The message is, try to avoid any lubrication, then if needed, only use oils which resist dust, and use it in only minute quantities.
Incidentally, the dial shown sitting in the ultrasonic cleaner in the top photo was the really filthy one I mentioned above, after cleaning. The N298GP phone this dial came from had lay open on the back of a retired gentleman's workbench for some 15 years, and the dial had been liberally lubricated with engine oil at some point. At first, I had considered this dial a write-off - I wish I had thought to take a "before" photo, or even a photo of the cleaning solution after I finished. Now look at it - it works as well as it looks! Yes, what you see is an Phillips/AE dial, not Northern, the one which had been installed on the Northern Electric phone when the Summerside exchange was automated in 1950.
The lesson is don't be afraid to try something like this - try if first on an old dial you really don't care about. This won't fix problems resulting from broken parts, mis-alignment of the contacts, or improper dial timing, etc., but in my limited experience, dirt and sludge are the cause of the majority of dial problems. You may be quite pleasantly surprised, and if it doesn't succeed, nothing lost!
If your dial has problems other than those caused by dirt, consider sending your dial to Steve Hilsz - http://www.navysalvage.com, for complete rebuilding. Steve can repair and test almost any dial at quite reasonable prices. He provides an excellent service and is highly respected by collectors.
"The Telephone on P.E.I."