Polywatch Gone Mad

[arron]

A number of months ago I had started fiddling with polishing acrylic crystals.  After watching a bunch of videos I tried polywatch by hand and didn't have good results; it made the glass hazy, which was difficult to remove.  I tried it again, same results.  I waived off ever using polywatch again.  So today i'm back to polishing crystals again, and i watch more polywatch videos that show great results, so i try my hand again.  as in one of the videos, i tried using my rotating shaft tool with a cotton buff.  first i tried on a junk crystal and it seemed to work fairly well; ;no hazing, and it took off the micro-scratches already there.  Then i tried on my good crystal and it turned into a sticky mess that couldn't be buffed out.  I don't know if i somehow got a bad batch of this stuff, because it looks so flawless on YT.  The crystal now is opaque (worse than in the attached picture).

I'm trying to salvage the crystal.  i tried rubbing in some more poly hoping to dissolve the existing poly but no dice.  i even tried goo gone.  I just did a little research and found that polywatch contains aluminum oxide and the following: "Aluminium oxide is soluble in aromatic organic solvents. An aromatic solvent is a solvent that contains an aromatic hydrocarbon such as naptha, toluene or xylene. Aromatic solvents are primarily used as solvents and diluents in various industrial fields."

 

Would it be safe to use naptha on the crystal to remove the polywatch?  or might that melt the crystal?  Maybe i should wet-sand it?  Has anyone else had this sticky/messy experience with polywatch.  Thanks, Arron.

[RichardHarris123]

The crystal might be cellulose not acrylic, there's a thread on here. 

[arron]

thanks for that reference @RichardHarris123.  i just read it.  in that thread a member was having the same trouble as me with a yellow crystal.  while there was nothing definitive as to why the problem occurred, some opined that the yellow crystal was celluloid and that polywatch may interact negatively with celluloid.  that would seem to explain why i didn't have a problem with the test crystal i used--i don't know what it's made of for sure, but it wasn't yellow, so maybe it's just acrylic.  in furthering my research i learned that naptha doesn't melt plastic or celluloid.  At this point i have nothing to lose, so i'll try those and then use sandpaper if necessary.  Thanks again.

[arron]

I thought i'd report back on my progress.  The naptha did little to nothing to remove the polywatch or the haze.  I spent over an hour wet sanding from 800 grit to 2k and then to 4k, as that is the finest paper i have.  the results down to 2k are in the attached pic; the 4k made only a slight improvement.  I have other liquid pastes and lotions to perhaps make some improvement, but given my experience with the poly i'm a bit hesitant to try them.  When laid on the watch i can actually see the dial fairly well, not perfectly clear of course.  The watch isn't worth much so i'm not sure i want to try and scrounge up another crystal, but we'll see.  The lesson i learned is to not use polywatch on vintage crystals unless you are somehow positive that it's not celluloid.  hopefully this helps someone.  Arron.

[JohnR725]

On 9/14/2023 at 4:19 PM, RichardHarris123 said:

The crystal might be cellulose not acrylic, there's a thread on here. 

That was basically kind of my question. Because the shape of the crystal it looks vintage what was the condition of the crystal like before you tried the polishing like for instance was turning yellow in color.

Okay need to improve my reading skills I see you answered the question yes it's vintage and is probably cellulose. The problem with watch crystals are they been made over a very long time over a variety of materials. Oh and yes there is a way to test for cellulose it's kinda destructive but it does burn really nicely.

 

Edited September 16, 2023 by JohnR725

[mikepilk]

If it's acrylic, I can polish a badly scratched crystal in about 5 minutes by hand. There's no need for power tools - it's easy to overheat and damage the acrylic if you do.

Depending on how badly scratched, I'll start with 400, 600 or 800 wet and dry (use some water). I'll move in a couple of grades to 1000, 2000. It takes less than a minute with each grade.
Then a final polish with Polywatch - again it takes less than a minute.