Sea biscuits, the delicate skeletal remains of certain sand dollars and sea urchins, often wash ashore as beautiful yet fragile natural treasures. Composed primarily of calcium carbonate, these intricate structures are popular for decorative purposes. Proper cleaning removes organic matter and debris, ensuring long-term preservation and preparing them for display.
Preparing Your Sea Biscuit for Cleaning
Start by gently rinsing the sea biscuit under cool, fresh water to dislodge loose sand, dirt, or marine debris. This prevents scratching the delicate surface during subsequent cleaning. After rinsing, inspect the specimen for any remaining organic tissues, such as dried internal organs or algal growth, which can cause unpleasant odors and deterioration.
The fragile nature of these calcified structures requires gentle handling. Remove any remaining organic material to prevent decay, discoloration, and foul smells as the biscuit dries. This prepares the sea biscuit for more intensive cleaning, ensuring its long-term integrity.
Effective Cleaning Methods
A common and effective cleaning method is a mild bleach solution. Mix one part household bleach with three to four parts fresh water in a container large enough to fully submerge the specimen. Submerge the sea biscuit for 30 minutes to an hour, monitoring closely to avoid over-whitening or structural damage.
After soaking, rinse thoroughly under running fresh water for several minutes, then submerge in clean fresh water for several hours, changing the water multiple times. This extensive rinsing removes all traces of bleach, which can degrade the structure. Prolonged exposure to bleach can cause the delicate calcium carbonate structure to disintegrate. Alternatively, soak the sea biscuit in plain fresh water for several days, changing the water daily to decompose organic material. This method requires more patience.
A less aggressive whitening option is a 3% hydrogen peroxide solution. Soak the biscuit for a few hours or brush the peroxide onto its surface. Hydrogen peroxide is milder than bleach, suitable for delicate specimens. Always rinse thoroughly with fresh water to remove chemical residues.
Drying and Curing for Longevity
Proper drying and curing prevent deterioration and unpleasant odors. Remove all moisture from the porous structure. Incomplete drying causes mold, bacteria, foul smells, and structural breakdown.
Place the cleaned sea biscuit on a towel or mesh screen in a well-ventilated area, away from direct sunlight. Direct sunlight can cause cracking or yellowing. Drying takes several days to a few weeks, depending on the biscuit’s size and ambient humidity. Adequate airflow aids moisture evaporation, solidifying its structure for long-term preservation.
Preservation and Display Tips
Once completely dry and cured, optional preservation enhances durability and appearance. Apply a solution of half Elmer’s glue and half water in light, even coats to strengthen the calcified structure and provide a matte finish. This protective layer shields the biscuit from dust and ambient moisture, reducing degradation. Allow each coat to dry completely for proper absorption and hardening.
For display, choose methods that minimize direct handling and protect the fragile specimen from accidental damage. Shadow boxes or enclosed display cases protect from dust and physical impact. Alternatively, cushioned stands or shallow dishes showcase intricate details while limiting breakage. A stable and protected display environment ensures long-term enjoyment of these unique natural artifacts.