Question: Please send information on how to clean chewing gum from concrete sidewalks. I have a steam cleaning machine that operates at 650 psi and a cold water cleaning machine that operates at 2000 psi. Either machine will remove dirt, grease, ice cream, dried soft drinks and chewing gum. But both machines leave an outline on the concrete where chewing gum has been, and I have not yet found a way to remove the stain. My method has been to spray the concrete with a mixture of a multipurpose powdered cleaner and cold water. After allowing this to stand on the surface about 20 minutes I clean with the steam machine if there is a lot of gum or the cold water machine if there is not. The result is fair, but not satisfactory to me. I do not want to use muriatic acid because I am usually working in the vicinity of a lot of people, cars, trees and plants.

Answer: Manufacturers of cleaning materials suggest two different methods of removing the gum. One method is to use a freezing agent made for the purpose. When this is applied by spraying from an aerosol can, the gum freezes rapidly and can be lifted off immediately while it is brittle. It is said that a 12-ounce can will remove a lot of gum. It is not entirely certain whether the stain will be left behind, but one manufacturer believes not. We don't know how many manufacturers supply such agents, but they are available from the following:

Arrow International

2611 South Central Expressway

Dallas, Texas 75215

Sprayway Inc.

484 Vista Avenue

Addison, Illinois 60101

The other method is to use any of several high-powered cleaner formulations. One company suggests using its paint stripper for gum removal; this is reported to be a blend of emulsified solvents. This material is diluted with water, applied to the concrete, left in place for up to 30 minutes, and then removed with a high pressure hot or cold rinse. Another company recommends an industrial grade solvent formulation that is used to remove grease, stains and epoxies, and which does some slight etching of the concrete. Another company has several formulations which are considered effective. For such materials you might inquire of:

A. C. Horn Inc.

1717 Paterson Plank Road

North Bergen, New Jersey 07047

L & M Construction Chemicals

3816 Blondo Street

Omaha, Nebraska 68134


Box 4040

Kansas City, Kansas 66104