Silicon Impregnator Can Darken Stone

All silicon-based impregnators should be tested first in an inconspicuous area. We have found that certain limestones and an occasional granite will become permanently dark. Apply the impregnator and wait at least 24 hours before making a determination as to whether permanent darkening might occur.

TIP Several manufacturers are producing impregnators that will not darken limestone. Check the resource directory at the back of this book.