Expert: Martin Meyer - 6/10/2007

Question
What is the best way to clean the platform escapement & balance and where are the lubrication points- if any.
Many thanks

Answer
Hi Sigmon,
    Platform escapements are extremely delicate and VERY easily broken. I don't recommend trying to do it yourself, but if you want to risk it and give it a try, here is what you should do.
    Remove the platform from the movement, usually four screws. Place it on something firm but not hard, like a styrofoam piece. Remove the balance wheel cock (1 screw) and remove it. You will probably have to very gently pry it up with a small screwdriver; there is usually a notch for this purpose at the back of the cock. VERY gently lift the balance cock up, and the balance wheel will come out with it, attached by the hairspring. Don't bend the hairspring! The tips ("pivots") of the balance wheel are needle-fine and exceptionally delicate; lay the balance wheel-hairspring-cock assembly down on its back somewhere safe. Remove the verge assembly by removing its cock (1 screw) and very gently lift it out of the platform. The same goes here regarding the delicate pivots. Remove the escape wheel and its cock (more delicate pivots).
    You can clean each pivot bearing (hole) with any good degreaser and fine brushes. Acetone, lacquer thinner, etc; all nasty chemicals, so keep good ventilation for your safety and no open flames. Some of the bearings will be jewels with holes in them, and another flat jewel (cap jewel) on top of the hole jewel. You must remove the cap jewels, which are held in by a tiny metal plate and an extremely tiny screw, before cleaning. You're working with miniscule parts here, so use fine tweezers and be careful not to lose any parts.
    After cleaning all parts of any dirt or dried oil residue, replace the caps on the jewels, and lubricate every pivot hole with a tiny drop of high quality watch (not clock) oil. It is debatable whether the verge pivots need lubricating; it depends which clockmaker you ask. Be absolutely sure that you do not get any oil on the hairspring.
    Now reassemble the platform assembly. It will not be easy getting the fine pivots aligned into the jewel holes for any of these parts. And be warned! If not perfectly set in the jewel holes, when you screw the cock down it will break the pivot and you will be in deep and expensive trouble. Also, the balance wheel staff (shaft) has a notch and pin on it which must be placed inside the crook of the fork on the verge assembly. When you mount the platform back onto the movement, the bottom pinion of the escape wheel will engage a contrate (crown-shaped) gear in the movement. There will be enough room for play in the platform screw holes to move the platform around a bit. You must adjust the  engagement of the escape pinion to the contrate gear so that the pinion engages the gear teeth affirmatively, but does not bottom out, that is, there must be some clearance between gear and pinion, so that they are not jammed together.
   I don't think this procedure sounds very easy, and I can assure you it is not! When I do it, I turn off the phone and close the door to the shop to prevent any distractions from my concentration. I will repeat that I don't recommend anyone but an experienced clockmaker doing this operation, as the danger of breaking parts is HUGE. I provide these instructions only in case you may like to "live dangerously."  By the way, there is no option to clean the platform without disassembling it, as cleaning will merely move the dirt around without removing it, especially in the case of the capped jewel holes.
    Good luck, if you decide to try this, and be very careful. Thanks for your question,  Martin