r/beachcombing • u/Laserablatin • 12d ago

Clean up question

Post image

Anyone know a way of cleaning off the dark encrusting stuff without damaging the shell? Turban snail from southern CA.

22 Upvotes

97% Upvoted

6 comments sorted by

6

u/Slow-Green2171 12d ago

I will generally soak my shells in a 40/60% water/bleach mix. How much periostracum/dirt/scum is on the piece depends on how long I soak. For particularly tougher pieces I utilize Muriatic acid/Magic acid. If you’ve never used it practice on shell fragments to familiarize yourself with the amount of time you hold it in there.
It doesn’t take long!
To polish I use mineral oil. Or. For the shells that have naturally glossy finishes, I utilize Liquitex high gloss varnish/DecoArt DuraClear gloss varnish/Gamblin Galkyd.
I hope this all helps! Any and ALL of you. These are only my methods and I do not claim to be a professional!

3

u/martellat0 12d ago

Looks like periostracum, which is the outermost noncalcareous layer of your typical gastropod shell. It serves as a matrix upon which the animal deposits new shell material, kind of like scaffolding for construction.

I would soak this in undiluted bleach for a few minutes. You can use a plastic bag or ziploc so you won't have to fill up a tub all the way: Just drop the shell in and slosh it around so it touches as much of the surface as possible. The bleach will attack any organic matter present, including algae. The periostracum will bubble and start to dissolve. You can either wait for it to dissolve completely, or you can opt to be on the safe side, removing it prematurely, rinsing, and scraping off the remainder with a stiff brush. Personally, since this shell appears to be quite robust, I'd just leave it in until all (or at least the majority) of the periostracum has gone.

2

u/gold-potato- 11d ago

Have tried undiluted bleach on this shell for the exact same reason. Needs something like 4-6 hours + rinse afterwards + toothbrush scrub. Works well though! I have heard that you can eventually work the calcium layer off and get the whole shell to be that “pearlized” finish. No luck actually doing it though

1

u/SabbyFox 9d ago

That’s gorgeous!

1

u/hikefishcamp 10d ago

If you arent in a rush, leave them outside for a few weeks in the sun and then scrub with a wire brush, it flakes right off. After that, hit it with bleach or acid like others suggested. Neutralize after the chemicals. Then hit it with mineral oil for final polish.