Watch Cleaning

The most basic watch repair task is cleaning and oiling, though it is by no means trivial. The only proper way to clean and oil a watch is to completely disassemble it, clean the parts, then reassemble and oil. Just oiling has its tricks, the key point is that too much oil is worse than too little. And oiling a watch without cleaning may be worse than just leaving it alone!

Cleaning agents

There are commercial products and these are most definitely the way to go. L and R products are the general recommendation and the regime I plan to adopt is to clean with L and R "extrafine" watch cleaning solution followed by L and R watch rinsing solution number 3 (probably 2 baths). (L and R sell both a rinse and a rinse number 3, and I have not a clue what the difference is, or why the number 3 is often recommended.) The usual scheme is to use 3 containers: wash, rinse-1, and rinse-2. Once rinse-1 gets corrupted, replace it with rinse-2 and pour out a fresh batch of rinse-2. Note that these products sell in gallon jugs costing $41.00 each, and must be shipped by UPS ground.

Note that L/R Extrafine is #109 and their "Ultrasonic" (non-ammoniated) is #677.

Zenith also makes cleaning solutions (and cheaper too), but most people seem to prefer the L and R.

It is said that the L and R rinse solution is a mix of 70 percent mineral spirits (stoddard solvent) and 30 percent naptha. This is probably true, but if you try to make your own mix, which I don't recommend, you should verify that it does not leave a residue by wiping some on clean glass and letting it evaporate. Mineral spirits are safer than Naptha and have a higher flash point.

The products you buy at the hardware store may not be excessively pure (although entirely adequate for thinning paint). The L and R products are tried and proven and will last a small user such a long time that the cost will be forgotten. Also note that the L and R cleaners contain small amounts of other ingredients that aid in cleaning.

Many people recommend the "Klean-Strip" brand, which is commonly available in many hardware stores these days. I don't know if it is because the name sounds good (which it does), or if they have had good results with these products, or both. Note that odorless mineral spirits, Stoddard Solvent, white spirits, and Varsol are all the same thing. Even naptha is more or less the same, it is just a more volatile (lower molecular weight) petroleum distillate. It is said that the reason the L and R rinse mixes naptha and mineral spirits is to raise the flash point from the dangerous 44C of naptha, but data I have found on mineral spirits indicates it can have a flash point as low as naptha.

Another option is to simply clean with naptha (which is what liquid coleman fuel or lighter fluid is). Again a check for residue using clean glass would be in order, along with extreme caution against burning the house down, not to mention inhalation with any of these products, which can have a significant content of carcinogenic aromatic hydrocarbons.

There are also water based cleaners. Some contain ammonia, which can dissolve some metals and cause damage, and most feel these are best avoided. Also it is essential to completely dry any parts cleaned in water to avoid rust. The old timers used carefully dried and warmed sawdust. These days people follow up water based cleaning with a naptha like rinse, or use a "hot box" (but see below to avoid melting shellac).

Ultrasonic Machines

The Bullova Watchmaster Ultrasonic is "the workhorse of the industry". Apparently there are different models, and I have been told that I probably do not want the A1 model. Here is one for $450, plus $50 to ship, which I am told is a good deal. This is item 2047 at Uncle Larry's watch shop.

Beware the shellac

As you probably know, the crystals on the pallet fork, and the ruby jewel are held in place with shellac. Never use alcohol or acetone to clean these parts as it will dissolve the shellac and release the jewels! There is even some concern about putting these parts in an ultrasonic cleaner. And some even say that these parts should be cleaned only briefly in the naptha type cleaners and then dried.

Some people dry watch parts in a heated box (heated by a light bulb) at about 100F. Shellac softens at 150F, so be careful if you do this.

Have any comments? Questions? Drop me a line!

Tom's notes / [email protected]