In this video I make a restoration of a watch that is The TANK of watches. This vintage watch was produced in ~1970 by Certina and its model name is DS2 (Double Security), the meaning of this is that the watch can be dropped, it can take hits etc, like a true TANK!
It’s a manual watch (you wind it via the crown). The movement is called cal 25-661. This video is only ASMR.
This watch seems to be the most robust watch that has ever been built. It has a big rubber shock absorber inside of it that separates the movement from the casing so no shocks will travel through the casing to the movement.
After the restoration the Certina watch works well. It runs around a couple of seconds per day +/- which is stated by the timegrapher and the amplitude is around 290+ degrees.
*Disassembly of the watch and check for problems along the way
*Inspection of all parts if they are worn or broken via the microscope
*Manual cleaning, pre-cleaning, I do this with Rodico (Bergeon), some toothpicks, pegwood and with IPA (isopropyl alcohol). Then after pre-cleaning I let all parts be in benzine and later a double bath of IPA (Isopropyl alcohol). The pallet fork gets a bensin bath and an Epilame treatment, balance wheel will only be cleaned with benzine.
*Cleaning the hour/minute/second hands and the dial, nothing more to do here but still it looks a bit better. Cleaning the casing etc with an ultrasonic machine.
*Lapping/polishing of casing was done with 3M lapping film from 320 grit to 8000 grit.After manual lapping I did a final polish with a Dremel tool in a couple of steps with cerium oxide with a couple of felt wheels (hard felt). A couple of passes with a very “watery” blend with cerium oxide made a fine mirror polish.
*Assembly and oiling all relevant parts
*Checking if the movement works fine and then checking it with the timegrapher
This is not a video tutorial, I’m just a hobbyist and might do things incorrectly.