How to Remove Plaster of Paris from Clothing

Plaster of Paris is essentially calcium sulfate. When mixed with a liquid, it becomes a liquid. As it dries it hardens to hold whatever shape it is placed in while wet. The longer the plaster is allowed to dry, the harder it will be to remove. Once dry, it will take additional time along with an acidic product to break down the plaster molecules. Follow these guidelines to remove the plaster while maintaining the quality of the clothing.

• Hammer
• Water
• Vinegar
• Citric acid
• Small brush (an old toothbrush works well)
• Spoon or dull knife
• Large garbage bag (or other large piece of plastic)
• Bucket

1. Dried plaster is brittle and can easily be broken up. If there are pieces of plaster on the clothing, lay it on a flat surface. Placing a large garbage bag, or other piece of plastic under the shirt will help make for easier clean up.
2. Gently tap all of the chunks with a hammer to break them up.
3. Brush with a soft brush to remove the dust and broken pieces.
4. Often times, a large amount of the plaster can be crushed and removed using only the hammer.
5. For any remaining residue, it will need to be removed with the aid of an acid.
6. Fill a small bucket or the sink with water. Add one cup of vinegar or a small amount of citric acid.
7. If you are concerned about the color being affected, test a small, hidden area first to check for any reactions.
8. Allow the clothing to soak in the acid/water mixture for several hours. The plaster will begin to soften as the acid begins to penetrate it.
9. Brush the areas with the small brush or scrape them away with a spoon or dull knife.
10. When all of the plaster is removed, launder the shirt as normal to remove any vinegar and plaster residue.

• If the clothing is white, it can be soaked in water mixed with Biz powdered bleach. Allow the piece to soak for several hours, then scrape the plaster away. Wash as normal when all plaster is removed.