Orlando asked: How do I clean plaster of Paris from a cement floor? I was working on a crafts project and my cement floor got some plaster of Paris on it.
Plaster of Paris is a form of calcium sulphate that forms a liquid when added to water and hardens over time. Once it has hardened, it will require a solvent to dissolve it to remove it. Cement offers a solid workspace that can tolerate the cleaners that will dissolve the plaster of Paris. Follow these steps to dissolve the plaster so it can be scraped away.
You Will Need:
- Acid (choose one):
- Citric acid
- Lemon juice
- Muriatic acid
- Plastic sheets (large enough to cover the plaster)
- Wide tape
- Biz powdered bleach
- Soft cloths
- Hammer (optional)
Steps to Remove the Plaster
*When working with acid-based removers, always use caution and wear gloves and protective eyewear for your safety. Test a small area first to ensure that there are no adverse effects to the cement.
- Begin by cleaning the area. Vacuum away any dust and dirt so you have a clean area to work with.
- If the plaster is on a smooth concrete surface, you may be able to carefully break it up by tapping it with a hammer. This will provide an edge to use the scraper to lift even more. Remove as much as possible and then proceed to dissolving the rest.
- Choose a dissolving agent. Many of these you may already have in your home. Muriatic acid is the strongest and requires the most precautions. It is commonly found with the grout cleaners at home improvement and hardware stores.
- While all of these acids will dissolve the plaster, it will take a good amount of time to do so – sometimes a couple of days. The challenge is to keep the acid moist so it can keep interacting with the plaster to soften it.
- To accomplish this, get a soft cloth sopping wet with the acid and lay it on top of the plaster.
- Cover the entire area with plastic and tape the edges down. This will keep the moisture locked in so it doesn’t evaporate while it is working.
- Check it each day and scrape away any loosened plaster.
- Remoisten the cloth and reseal it under the plastic.
- Repeat this process until all of the plaster is removed.
Additional Tips and Ideas
- Plaster of Paris dries hard, but does wear down over time. If it is exposed to the changes of weather, it will wear even faster.
- If you can soak the plaster in water, it will dissolve over a longer period of time. Mix in Biz powdered bleach to expedite the process.