Roland, I'm not a very expert chemist either, but I think I may help answer
your question about bleach.  Both hydrogen peroxide and calcium hypochlorite
are strong oxidizers which is the basis of their bleaching effectiveness.
The concentration of the product makes a difference too.  Here in the USA
calcium hypochlorite can be found in concentrations from about 4% up to
nearly 10%.  Most of us probably use the "standard" 5.25% household bleach
diluted about 5 to 1 for cleaning shells (about a 1% solution).

The environmental benefits of hydrogen peroxide are probably real since the
chlorine in the calcium hypochlorite forms some pretty nasty secondary
products, and some of them are quite persistent in the environment. Bert

-----Original Message-----
From: Conchologists List [mailto:[log in to unmask]] On Behalf Of
Roland Günther
Sent: Monday, December 13, 2004 10:29 AM
To: [log in to unmask]
Subject: once again: cleaning

Hello everybody!
Is it because we shell collectors are such orderly people or why do we spend
so much time discussing cleaning methods?
Anyway, I would like to add two things to this neverending discussion:
Firstly, after our recent discussion about ultrasonic cleaning I bought an
ultrasonic cleaner on ebay for 30 Euro including postage. (For a new one
that is.) After experimenting this afternoon with a bunch of Hexaplex
trunculus from this years summer holiday I would estimate that I can reduce
cleaning time for about 30 - 50 percent, which is not bad. From my first
experiences I would say that the cleaner does remove only a small part of
the encrustations but loosenst the rest sufficiently so you can scratch them
off easier. Also it seems to be effective in removing the very fine dust
that is pressed into the structure of the shell by scratching. It isn't any
good in removing algae or very hard encrustations. I will do some more tests
during the holidays and tell you the results.
The second topic I would like to address is bleach. When we're talking about
it it usually is chlorine bleach. I recently looked more closely at some of
the bottles available here in German drugstores and found out they are all
based on hydrogene peroxid. My question is why is that so? Is hydrogen
peroxide more effective or more eco-friendly? Is anyone of the two better
suited for shells? If you know more about chemistry than I do, help me
out...

Greetings, Roland

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