Q. What is the best way to remove smoke residue from a fireplace made of irregular boulders? Earl Burroughs Lyons, Colo.
A. Smoke residue usually yields to scouring powder that contains bleach. Apply with a stiff-bristle brush. Some alkali detergents and commercial emulsifying agents, either brush- or spray-applied, and given sufficient time to work, also may perform well. Test first on a small area.
For small stubborn stains you could apply a poultice, using trichloroethylene. Take care to avoid the fumes.
An effective commercial masonry cleaner is ProSoCo's Sure Klean fireplace cleaner. If it is unavailable at your local hardware or supply store, get in touch with the company at 1040 Parallel Parkway, Kansas City, KS 66104. The phone number is: (913) 281-2700.