Re: Feather tracks in lens coatings - any preventative?

Hello Group,

Am I very wrong in suggesting, that nobody in this
thread has convincingly presented any evidence that
the "hoary frost" is actually a fungus, that is a sapro-
phytic plant?

Could it not be, that it is the formation of microcrystals
within the layers of coating which were applied to the
lenses?

GR.


"Charlie+" <charlie@xxxxxxx> wrote in message
news:c7ep541rr7ogn95omnitc0um66130qu7ce@xxxxxxxxxx
On Sat, 21 Jun 2008 00:03:12 -0700, "Edward Hennessey"
<halozzyzxhaloMINUS123@xxxxxxxxx> wrote as underneath my scribble :


A very interesting tack to go down, thank you! I collect glass and some
of it
is hundreds of years old - not a sign of such fungus is visible,
crystallization
is the usual deterioration mode for ancient glass, though very difficult
to
tell the mechanism for glass that has been buried or sunk for a long time.
My guess is that this etching fungus is a child of the low pressure vapor
coatings age.
Charlie+

It came to me that another excellent resource to check would be
art conservators. As they deal with objects of all kinds, glass and
instruments
among them and are very studied in my experience, my bet is they would
have
a number of operational procedures and literature references. Plus, they
are
some of the nicest people to talk with as long as one is courteous and
focused.

Regards,

Edward Hennessey



.

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