Also posted this tread on the seiko forum (because of the watches), but would be equally good here, as this is aimed at Acrylic Crystal, found on plenty of vintage watches.. hopefully this helps someone!
Recently i posted this thread showing my bargain car boot find - King seiko 5246:
Awesome watch, which had only one problem... the Acrylic crystal was very scratched. Thanks to the suggestions of stefano34 and Pandamonium i have managed to turn this:
Granted, this is not as good as a new crystal... but its very close! Plus i have not had to spend lots of time and money finding the right replacement crystal - if even possible!
This is how i did it:
Firstly, sorry if this is common knowledge and something you guys do all the time. But i did do a thread search and did not find anything.
Also, im sure people have proper equipment and better ways of doing this... but this is my first steps into watch (cosmetic) repair and am amazed how easy and cheap it is to do this.
Firstly, you will need a watch with an Acrylic Crystal which is in need of repair. Luckily, a work colleague has a vintage seiko that had a nasty scratch, plus normal wear an tear. After telling him about my DIY repair to my KS he gave his watch today for the same treatment.
Its a 1975, 7006-5000. Notice the scratch from 7 to 1
Once you have the watch, you need the tools... I say tools, but infact, its stuff you are likely to have in the house - if you have a female in the house!
The first thing. A nail polishing block - Ask the ladies in the house, or go to your nearest Supermarket? Boots? Superdrug? and it looks like this:
Each side has a different grade of glass paper, from a rough grade to a side that buffs. From what my girlfriend says, this is standard and each side is normally numbered from 1 to 4! In the case of this one, 1 was the rough side, going through to 4 the buff ('Shiner') side. Please note, I have not used side 1 (the roughest) at any point. One of these will cost about £2...
The second thing you will need is.... Toothpaste:
Nothing special.. I assume the cheapeast tube will do the job?
Right, when i did my KS (I have since done 3 other watches this way), i have left the crystal in the case. But, as this watch has a very easy crystal to take out, I did... but you dont have to!
I then started but using side 2 (called ridge remover on this block) in a circular motion to 'sand' the top of the crystal (This is the only time i have needed to use side 2, as the scratch was quite deep). When i first did this, i thought i was killing the crystal... it looks like this:
If you wipe this off with a damp cloth, it does not look as bad, but you will see the crystal has lots of mini scratches... Once i could see the main scratch had been rubbed out, I moved onto side 3 "nail smoother"
I have also found adding a bit of moisture to the surface when doing this helps.... once you have worked out the mini scratches, you are left with a slightly cloudy crystal with minute scratches. Wipe off the crystal powder and get the toothpaste.
Using a cloth ( I used kitch towel/paper) rub the tooth paste around in circular motions once again for a couple of minutes. I had to repeat the sanding with side 3 and toothpaste buffing twice to pick up all scratches.
The end result:
Like i said earlier... this is not as good as a new crystal... but its very close. And with a watch like this, when a replacement is hard to find, this gives many more years of use to a tired crystal.
The one thing i would say if you plan to do this, is: TRY IT ON A CHEAPY OR CRYSTAL THAT IS ONLY GOOD FOR THE BIN!!!
Thanks again to the guys that suggested this and sorry to those of you that think this was a waste of your time reading (as you already know this)or a bit amateurish.
But to Noob's like me... I hope this helps