Hi Ellen,

Whenever I'm in doubt, I liberally coat the areas I'm worried about
in Vaseline. This even stands up to brief dunkings in water with
small amounts of muriatic acid, which is necessary (in my opinion)
for certain shells that won't come clean any other way, like some
Melongena corona specimens. Others have told me that they immediately
coat their helmets' shields in Vaseline, as the shield area seems
particularly fragile.
Good luck!

Best regards,
Jim

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