I am not a chemist so as far as I know silver tartrate is immune to this or
my original impressions are simply wrong. In that case please accept my
apologies in advance for disturbing your peace of mind but I could not just
let this go by.
I strongly recommend that those of you with access to real chemical advice
get a local answer to this question and post it back here. In the meantime
I posted an inquiry to the rec.pyrotechnics and sci.chem groups on the
internet. The only complete reply I got is copied below.
Until someone comes up with more definitive information I suggest you wear
serious eye protection, avoid glass containers, work in tiny quantities, and
dispose of all solutions immediately after use. I do not want to ever get a
post to this group that starts with "I regret to inform you ... ."
E. Robkin
erobkin@uwcmail.uwc.edu
--------------------------------------------------------------------
--- Forwarded message follows ---
From: silent1@ix.netcom.com (The Silent Observer)
Subject: Re: Ammonia & Silver
Date: 26 Dec 1995 21:55:11 GMT
In article <erobkin.648.820008212@uwcmail.uwc.edu>, Eugene Robkin
(erobkin@uwcmail.uwc.edu) says...
>
>An alternative photography list I subscribe to has recently begun
>discussions of a new image forming chemistry using ammoniacal
>solutions of silver tartrate.
<snip>
>
>Would minimizing the holding time for the ammonia mix be
>sufficient for safety, is safety impossible to achieve, or is
>there no problem? What is the advice for this?
>
The specific conditions involved in explosions of mirror silvering
solution are met when a dark precipitate forms from an ammoniacal silver
solution. I can't seem to locate my copy of the _Amateur Telescope
Maker's Handbook_ just now, but I remember the primary caution being to
keep an >excess< of ammonia, in order to keep the silver complex in
solution.
Most likely, the chemical that forms is a complex known as fulminating
silver -- this is not the same as silver fulminate (the fulminic acid
salt, usually derived by reaction of dissolved nitrate with ethanol),
but is in fact more sensitive. Silvering solutions that were allowed to
form precipitate have been documented to be set off by a sunbeam, by
friction involved in opening a glass stopper, or by other seemingly
innocuous precursors.
I'd be inclined to suspect that silver tartrate would be safer than
silvering solutions, which have in common with fulminates starting from
a nitrate solution. Tartrates, AFAIK, are not generally explosives, nor
significant precursors to explosives.
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