Hi,
ZrO2 is rarely used by coaters. It takes quite a bit of power to get
it going and its decomposition in an E-beam is on par with SiO2. I
usually run the coatings very slowly and after pumping down to better
than 6X10-6 Torr. Our thickness measurements are in the accuracy of
1-2%.

When using silver, I feel that a multilayer overcoat is critical for
protection.

It took us about a year to get our mirror coatings down. There's no
money in small mirror coating operations, though we've done several
hundred mirrors for one manufacturer.

We may be able to acquire a Balzers 48" Box coater in the near future.
This unit has optical monitoring and ion-assist with 3 E-beam sources.

Al M


(Dan Chaffee) wrote in message ...
On Wed, 23 Jul 2003 16:36:38 GMT, "Bryan Greer"
wrote:


Hi Bryan,

As to your specific question, I can only say that the quality of the
overcoat has everything to do with the durability of your silver coating.
TiO2 and SiO2 -- when properly applied -- is a very effective protection
layer for the metal under it. These materials are very hard, but the SiO2
in particular can be easily applied wrong. SiO is easier to deposit, but
isn't as durable.

I've always wondered if the scatter would be the same for either
metal. Obviously if one chemically silvers their own mirror and then
burnishes it as I used to do, the scatter will be higher than Al, but
evaporating eliminates that step and would seem to produce
scatter not worse than Al.

Dan