If you wish, you can paint the sand dollars with acrylic paint and allow them to dry before applying the glue solution.
Collecting sand dollars is rewarding. They have striking shapes and designs and can be used for craft projects or displayed in a room. However, sand dollars picked up from the beach will be dirty. Before you use them for decor items, you'll need to clean and preserve them.
Fill a bucket with water. Place the sand dollars into the water and leave them until the water becomes cloudy with dirt.
Remove the dirty water and fill the bucket with clean water. Repeat this process until the water remains clear. Empty the water from the bucket.
Mix a solution of half bleach and half water and add it to the sand dollars in the bucket. Leave the sand dollars in this solution for a maximum of 10 minutes--if left any longer, the bleach can cause the sand dollars to disintegrate.
Pour the solution from the bucket and rinse the sand dollars well under running water. Set them out in the sun to air-dry.
Mix a 50/50 solution of white school glue and water. Paint the mixture onto the sand dollars to whiten and preserve them.
Allow the sand dollars to dry before using them for projects or display.