Cleaning Sea Shells with Muriatic Acid

Beach combing has been a hobby of mine since I was a little kid. It's something that I go through phases with, but I always come back to it when I need to connect to nature or myself. 

It wasn't until I moved to Hawai'i that I really got into sea shells. The shells here are just so different than anywhere I've ever been, and absolutely blow my mind with their natural beauty. But sometimes, that natural beauty needs just a little bit of TLC.

Many people clean their shells with baking soda, vinegar, or even bleach (not together!), but I've found the ultimate method that will take your stinky, dull shells to bright, colorful and shiny in no time!

What you'll need:

Muriatic Acid
Water
Baking soda
Two Buckets or large containers
Tongs and/or a colander or sifter for smaller shells
Safety goggles/protective eyewear
Face mask
Gloves
Optional: mineral oil

Begin by setting up outside or in a well ventilated area. Do this away from any stainless steel appliances as the acid can cause discoloration and deterioration. Put down towels if you want to protect the surfaces you're working on and wear your protective eyewear, gloves and mask. These chemicals can be harmful if ingested or if splashed into the eyes, so please wear all of the safety equipment listed here!

Start out with both containers filled with water. Add your muriatic acid to one of the water containers. Generally, I'll start with a 3:1 ratio of water to acid. 

Either using tongs or a strainer of some kind, dunk your shells into the acid solution. Depending on the condition of your shells, you'll want to let them sit in the solution anywhere from 10 seconds to a minute. Shells with lots of algae and calcification may need more time. Keep checking on your shells, making sure not to leave them submerged in the acid solution for too long. If a shell is in there too long, the acid can eat away at the shell causing holes and cracks. 

Once you think your shells are done, remove them from the acid solution and place in the water container for a rinse.

Once you've cleaned all your shells and they've been rinsed, you'll want to add baking soda to your acid solution and the rinsing water. This will neutralize the acid before you dispose of it so it won't cause any damage to your sink or pipes. 

Once you dispose of everything, you can leave your shells to dry. You may notice once they're dry that they aren't quite as shiny as they were when they first came out of the water. That's normal! If you want to display your shells with that shine all the time, you can lightly coat your shells with mineral oil to maintain that glossy finish. 

Before:

After:
I ended up putting a few of these back in the acid solution for a little while longer, but you can see how quickly a lot of the calcification was removed and you're able to see the spots on these cowries and even some beautiful purple color that was hiding before. 
This is such a fun activity for beach combers to do at home. I just encourage safety first for this activity and of course, making sure to use your best judgement when beach combing and only taking shells that are empty.
Happy shelling!

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