The problem with removing calcareous deposits from shells is that the
deposits are usually composed of the same material, or at least very similar
material, as the shell.  Therefore you can't use chemical methods to
dissolve the deposits (as you can with non-calcareous deposits and
periostracum) because any chemical that will dissolve calcareous deposits
will also dissolve the shell.  So you have to resort to physical means of
removal such as scaping, picking, brushing and sonicating (use of an
ultrasonic cleaner).  My initial assault on calcareous deposits is usually
with a wire brush.  For substantial deposits on sturdy shells I use a 3 inch
rotary wire brush mounted in my electric drill.  For lighter deposits on
smaller, more delicate shells I use a 1 inch rotary wire brush in a Dremel
tool. This often completely removes the deposits, or at least removes most
of the material so that there isn't too much left to pick off with a needle
or other sharp instrument. The bristles of the wire brushes should be steel.
They sell softer wire brushes made of brass or other metals, but these do
not cut through the deposits nearly as well, and they may leave a metallic
deposit on the shell.

> ----------
> From:         Conchologists List on behalf of David Kirsh
> Reply To:     Conchologists List
> Sent:         Sunday, August 21, 2005 9:28 PM
> To:   [log in to unmask]
> Subject:      cleaning question
>
> OK, I know we probably covered this recently but I can't find it in the
> archives.
>
> How do I remove calcareous algae from an outer lip without damaging it?
>
> Thanks in advance,
>
> David Kirsh
>
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