Jump to content

Recommended Posts

Since I recently acquired 21 watches in various states of function and condition,  I thought I'd share my technique for restoring acrylic crystals.  As a warning, there are items used in this procedure which can be harmful if used improperly, so please always read the manufacturer's warnings and heed them, thank you, and enjoy.

20200123_055441.thumb.jpg.5fe28043e7bd6294b12fb45d08a0e642.jpg

I prefer to begin with a dual sided Emory board similar to what is used in nail salons. They're flexible and conform to the curve of the crystal. The one I use comes with 2 different grits,  one coarse and one fine,  400 and 600 grit respectively.  I dip the Emory board in water and ensure a small puddle forms on the crystal. I begin with the coarse grit and start with a circular motion,  applying steady pressure.  As I sand, I rotate the watch in small increments being careful to not stay in one place too long and to maintain a circular sanding motion. I follow the natural curve of the crystal as well,  unless it's a flat crystal. After a few minutes,  I stop and check my progress.  I wipe off the water and acrylic residue and look for any obvious, deep scratches that remain.  If not,  I proceed to the next step, if so, I repeat the previous steps.  When I'm satisfied that the deepest scratches are gone, I thoroughly clean the crystal and wipe it dry. I now flip the Emory board to the fine side and repeat the previous procedure of circular motions.  Knowing when you have done it enough is honestly an issue of feel. When you first change grits,  the surface feels rough and there is resistance as you sand,  but that lessens as the deeper sanding marks are made shallow by the finer grit. This process should take less time than the first step.  Again I clean off the residue and thoroughly dry the crystal.  If im happy the the smoothness of the crystal,  I can now move on to the final polish. 20200123_060153.thumb.jpg.3f09f73493c50c90a0cfb44a6fb29a73.jpgI use a polishing compound from my employer that works amazingly,  however any glass polishing/scratch remover that contains Cerium oxide will work fine. For this step I take a cotton cloth and fold it over twice giving me 4 layers of fabric. I then dab a penny size drop of the Cerium Oxide cream onto it and then press the crystal firmly onto the cloth.  I then swirl the crystal around and around in a steady, circular motion, maintaining a firm pressure as I work. I rotate the crystal every few moments and I rock and tilt the crystal following the contour of the crystal. After a couple minutes of this action, I stop and wipe away the residual cream and inspect my progress. Most times, one cycle of the Cerium oxide cream is adequate, however,  if you miss a spot, repeat the process. The initial penny size drop of the cream is almost always enough. If you're  happy with the results you can wipe away all the residue and enjoy your work.

20200123_062131.thumb.jpg.99583ea874fdd94010edce78eea93592.jpgBTW, cerium oxide will lightly polish metals as well, similar to Brasso. This can help to remove scuffs,  light scratches, Oxidation and other residues on older watches. Lastly,  this entire procedure can be perform without ever removing the crystal from the case, as long as you are mindful of the case. Thank you for your time in reading this,  hopefully I've enlightened you and added a new tool to your watchmaking toolbox. (The crystal used in the photos of this procedure has microscopic crazing cracks from age and heat which are deeper into the crystal and this procedure does not remove those,  however,  for me it looks great.)

Edited by FLwatchguy73
  • Like 2
  • Thanks 3
Link to post
Share on other sites

Nice end result.  I use a similar process finishing off with polywatch.  Care is needed to not press too hard, let the abrasives do their job.  If there are any deep scratches or deep micro-scratches, too much pressure will tend to make them worse, and can even become so bad as to make the crystal needing replacement (I know I have done it, especially with ladies watch sizes!!).  To protect the case a use duct tape or similar which stays in place even with some wetness present.

  • Thanks 1
Link to post
Share on other sites

 to take out scratches on the crystol,  i use "wet or dry" sand paper.  600 grit and finish with 1000. sand by hand in a circular manor. after 1000 grit,  polish with tooth paste.   vin

  • Like 2
Link to post
Share on other sites
  • 2 weeks later...

Of my antique show haul,  I have 2 watches left to overhaul. This watch is third from last. As you can see,  the crystal was in awful condition. This is yet another Birth year watch. I'm still amazed how great these Timex's look after some positive attention is given to them. 

Before20200206_055334.thumb.jpg.d732410462c220a35f25533ecb075f45.jpg

After

 

20200206_080048.jpg

  • Like 3
Link to post
Share on other sites


  • Recently Browsing

    No registered users viewing this page.

  • Topics

  • Posts

    • Could some one please tell me if I have the date jumper on this MST 521  up the right way. It flew away when I took the cover plate off. Managed to find it and the spring but might not be so lucky next time....Thanks
    • How did this project eventually go? The GMT-MASTER does not have an independently adjustable GMT hand. Basically, it points straight-up at midnight and straight down at noon. The bezel is rotated to use that GMT hand to indicate the second time zone. (you can pull the GMT setting gear from an ETA to simulate this lack of function) The GMT-MASTER II does have an independent GMT hand, which can be set. This allows three time zones to be possibly set. The Rolex 1655 has the same movement as the GMT-MASTER and the bezel is fixed. Purpose was to indicate day and night while in the darkness of a cave. I worked on a (crappy) replica of a 1655 which had the "quick-set" GMT hand. I think the dial is way to busy and difficult to read as well, but that's another story...
    • Welcome to the forum.
    • Turns out (accidentally) dropping it on the floor opens it allright:) Verzonden vanaf mijn iPhone met Tapatalk
    • Hi Tom,   Mine machine is working fine but slightly out of sync (I still didnt figured out why as in the biggining it was completly fine, no issues), so I use manual overide button to move between cycles, its abit tricky as I have to watch metal disks which turns things on/off if not it will jump to another cycle (it cause a bit of an issue as it wont spin long enough to remove fluid between jars).   Regarding documentation - one Ive scanned for you was received from Elma after I contacted them, they told me that they dont have any shcemtics for this machines, I only got electronic schema for RM-90 if I recall correctly which is much more advanced and newer. Because machine is not working as I would like it, Im thinking to create a new electronic system for it based on arduino or something like that, Im not a programmer so it might be too diffcoult for me. If mainboard replacement for RM-90 would be cheaper I could use that for my machine - just got that idea  right now :). Still some parts are the same between those two machines - jars, possibly motors, heating plate etc.   Im mostly interested in American pocket watches, actually South Bend only :).   Regards,    Rafal
×
×
  • Create New...