A fine summary and most helpful as such.  It's nice when someone puts the bits and
pieces together.
 
Marlo
 
Paul R. Monfils wrote:
 
> Hi Ted,
> You really covered all the bases in your question.  IF you protect your shells
> from their three arch-enemies (light, moisture, and to a lesser extent, heat),
> all of which you alluded to, then they will remain fresh-looking for many
> years.  I don't think of fungus as an additional category - if you effectively
> protect your shells from moisture, you won't have fungus problems.  Fungi are
> living, cellular organisms, and just like us, they need water to grow - not a
> lot - just a bit of dampness will suffice, but fungi cannot grow on truly dry
> substrates of any kind (Note that dessicated foodstuffs, like flour, cereal,
> etc. do not get "moldy" as long as they remain dry.  Moist foodstuffs like
> bread and fruit readily become moldy - and so does cereal if you moisten it).
> Fungi are problematic in shell collections primarily in warm, humid (typically
> tropical or sub-tropical) climates.
> There is sort of a little Catch-22 here.  Sunlight (actually the ultraviolet
> radiation in sunlight) inhibits the growth of fungi, but it is also
> destructive to shell pigments.  Darkness protects pigments, but encourages
> fungal growth.  So, since shells have to be protected from light, it is
> especially essential to maintain low humidity in order to control fungi.  The
> various sealants that have been mentioned (oils, silicone, etc.) help by
> forming a barrier against moisture.  A shell should be thoroughly dry before
> applying such substances.  If there is water in the pores of the shell when
> sealants are applied, you may seal the moisture in, and the moisture itself
> will act as a barrier to the effective penetration of the sealant.  Such
> sealants should be applied liberally to the dry shell, rubbed (on a smooth
> shell) or brushed (on a rough shell) into the shell, and then thoroughly wiped
> off the external surfaces.  If applied too lightly, they won't penetrate into
> the shell matrix effectively.  If not wiped off thoroughly, they will make the
> shells oily or sticky to the touch, leave oily spots in drawers and on labels,
> and attract dust like a magnet.  On rough textured or heavily sculptured
> shells, where it may be difficult to effectively wipe off the excess sealant,
> a fine spray of water can physically remove the excess from the shell's
> exterior, without removing sealant that has penetrated into the porous matrix
> of the shell.
> Heat, as such, is not a problem when shells are stored under normal indoor
> environmental conditions, provided the humidity is low.  However, given the
> presence of moisture, fungi will grow faster at warmer temperatures (which is
> why we refrigerate moist foods).  Also, shells stored under unusually hot
> conditions, for example in an uninsulated attic or car trunk where the
> temperature may reach 150-200 degrees fahrenheit or higher on hot summer days,
> may fade somewhat, even in the absence of UV radiation.
>
> Paul M.