Things You'll Need
Plastic putty knife
Dry soft cloths
You can purchase pure acetone at home and garden centers or use acetone-based nail polish remover.
Do not apply water or a water-based cleaner to the expanding foam residue as it will speed up the curing process. If it cures, you won't be able to remove the residue with acetone solvent.
Acetone can damage painted surfaces, as well as finished wood and stone. Use the least amount of acetone necessary and remove it completely with water once the foam residue is gone.
Expanding foam fills gaps as it seals and insulates. Although it's simple to apply, removing excess foam, once it has cured and expanded, can be difficult since you will need to sand it down. Uncured expanding foam, which is still soft and moist, can be removed with a solvent. In fact, attempting to clean uncured expanding foam residue with a non-solvent solution may actually cure it rather than clean it.
Wipe away as much of the expanding foam residue as possible with a plastic putty knife and a dry soft cloth.
Moisten a second dry cloth with acetone.
Rub the acetone on the expanding foam residue lightly then apply pressure, as necessary, to rub the surface in a circular motion. Re-moisten the cloth with acetone as needed.
Wipe the acetone residue away with a soft cloth moistened with water. Remove all of the expanding foam residue before applying the water.