I've had no issues with Acrylic crystals in the past. Sinn even uses them in some models (103 I think). Can generally buffed with Polywatch with no problems. Though I'm sure there can be one off cases where that won't work, I wouldn't worry too much about it personally. But of course YMMV.

 

Sapphire and Hardlex for me, Please!

 

The Bulova Accutron watches from 1960 to 1977 (tuning fork) used acrylic crystals. Although they scratched very easily. They were also easy to repair. A little Novus plastic polish and some elbow grease usually gets good results. A light careful use of a Dremel at slow speed works for the nasty stuff.

 

The Max Bills and most of the Meisters have a Sicralan-coated plexiglass, not acrylic, crystal.

From what I've read, the Sicralan creates issues with trying to buff out scratches.

Plus, is plexiglass prone to cracking in a way that acrylic isn't?

I've never read complaints about acrylic or hardlex suddenly cracking.

 

From my understanding Plexiglass is just a brand of acrylic. Like Kleenex is just a brand of tissue (but I always hear people ask for a Kleenex....I digress).

So in theory it would be the same thing. If it has a coating applied, kind of like Dan Henry has a sapphire coating to their mineral, then it could see it posing a problem. But in it's purest form, it should be identical. My caveat is I could be completely wrong about all of this.:noidea:

 

If it's good enough for an Omega Speedmaster it's good enough for me.

They may scratch but they don't shatter which is a definite downside to having a piece of glass strapped to your wrist. They're also relatively cheap to replace, so you can have a sparkling new one when Polywatch just isn't doing the trick anymore.

 

Not sure what effect the Sicralan brings to the equation. But the acrylic crystals used on the Accutrons were much softer than plexiglass. Does plexiglass break. Yes I can tell you first hand. I played ice hockey for eight years. Seen many games held up while they replaced a 1/2 inch piece of the stuff that got broke by a hot shot. It breaks in large shards. Not like safety glass. On a piece as small as a crystal. I'd say they must have done some testing with it combined with Sicralan to determine that it offers some qualities that others don't. I still think it would scratch easily. Tough call. Like to see what the manufacturers have to say about it. What do they promise ?

 

What do they promise ?

The Junghans glossary website says this:

The SICRALAN MRL UV coating process was developed by the GfO in Schwäbisch Gmünd for suppliers in the automotive industry. Both German manufacturers – the GfO and the Junghans watch factory – transferred this proven process to timepiece glasses and have agreed on exclusivity. This transparent coating ensures functional and aesthetic added value: increased scratch-resistance, improved UV and chemical resistance, as well as a more intense plexiglass gloss.

I don't know, though ...

For a +$1K watch, it just seems like a pretty big corner that was cut. But then, what do I know????

Maybe, for the kind of contours they needed on the crystals, plexiglass was the only reasonable way to go.

 

I like acrylic crystals