This is a vintage Seiko 6039-7049 “Turtle” I recently serviced for a ClockSavant customer. The sequence of pictures in the video below highlights some key points about watch servicing. After full disassembly you see the dirt commonly found in unserviced watches. The black paste-like substance is a combination of dirt, old oil, and metal filings that acts like a grinding paste. So when these are worn regularly without servicing, the watch’s key components are ground-down, eventually destroying crucial components of the watch. Next you see a plastic part that’s used for the date mechanism. The point here is not that the part is plastic, such parts are found in 1960’s watches onwards and are not necessarily an issue. However, such parts require correct handling during servicing. This part, called a date driving wheel, was improperly cleaned and heated in the past and effectively melted and bonded around its mainplate arbor. As a result, it required significant force to turn. I repaired the part by re-shaping the center hole. I believe this watch was not fully disassembled when serviced in the past which accelerates the “grinding paste” we see along with the melted part. As I’ve discussed in the past, not fully disassembling has become a norm as it saves the watchmaker money, requires far less watchmaking skill, can give the customer the cheap price they are after, and takes much less time. The fact is, you need to disassemble everything to do the work well (fully clean, fully lubricate, and identify issues) and that’s just the way it is. This has been a common point I’ve raised many times. Leaving most of the dial-side and setting parts in-place, as one example, is a common shortcut as-is not removing something called “cap jewels.” Also not removing the mainspring from the barrel and cleaning or replacing the mainspring is yet another shortcut. There seems to be this misconception that ultrasonic bubbles are magic and permeate dirt in some mystical way even when parts are screwed-down and bound to each other. And there’s a mystical oiler that reaches underneath metal and plastic to lubricate it. It doesn’t work that way.