How to Smooth Out Plaster of Paris

Plaster of Paris is a fine white powder that, when mixed with water, is used as a building material. When it is sufficiently mixed with water, the plaster is heated to 140 to 180 degrees Fahrenheit. In this heated state, the plaster looses ¾ of its water content, thus producing the hard and dry plaster. This material is used for building various moldings on walls and ceilings, as well as for sculptures. Artists and craftsmen use Plaster of Paris because it is easy to control and manipulate, and because it sets fast. The plaster will often need to be smoothed to achieve a seamless texture on a project.

Mix enough of the plaster and water together so that you have enough for your project.

Apply your final mixture onto the surface or sculpture with which you are working. In order to get all of the plaster onto the surface, transfer big chunks of the plaster with a large spoon or a scooper, if you have one. This way, you don’t have to actually touch the plaster with your bare hands.

Use the trowel and putty knife to smooth the plaster evenly once the plaster is out of the bowl and onto the surface or object. Since Plaster of Paris is an easy mixture to work with, smoothing it out is not difficult. However, make sure you don’t take too much time on the small and minute details of smoothing the plaster since it does set quickly.

Use your trowel to sand the chunks of plaster you transferred from the bowl. Depending on the size and shape of your surface area, smooth the plaster accordingly. Use the smooth bottom of the trowel and guide the plaster evenly across the entire surface. Use the pointy edge of the trowel to push the plaster into any corners or tight spaces.

Use the scraper to remove plaster from any surface where it is not desired. You can also use this tool to remove any excess plaster once you have covered your entire surface. A putty knife is also a beneficial tool you can use along with your scraper to remove any plaster or even patch up any holes or indentations on the surface, making the surface as smooth as possible. Before continuing any carving or painting, wait until the plaster has thoroughly dried off.