The majority of modern watches in water-resistant cases will only require the movement’s parts to be degreased. This means washing off the old oil so that fresh oil can be applied. Many ‘old school’ watchmakers used benzene or pure Naphtha. In the modern age, both of these have been found to be bad for your health if inhaled.
You will quite often see watch repairers using lighter fuel as a modern replacement, as this still contains Naphtha. However, many watchmakers are blissfully unaware that modern lighter fuel is contaminated with a small amount of oil, making lighter fuel a very poor degreaser. Very small particles of oil will be left on any part that you try and clean when using this substance.
If you apply oil to the surface of anything that has been washed in lighter fuel, the oil will have spread by the next day. The only thing that lighter fuel is good for is cleaning mainsprings, and even then only when the fuel is applied to a lint-free cloth and used to wipe the spring clean.
Don’t be fooled into thinking that washing watch parts in degreaser is a quicker way of cleaning a watch. You would … Continue reading...