An alkaline solution of ammonia is used to clean the red sandstone. ASI uses a special biocidal treatment for the sandstone protions that are hidden from sun and gather moss and algae because of humidity. Preservatives are also used to increase the longev
An alkaline solution of ammonia is used to clean the red sandstone. ASI uses a special biocidal treatment for the sandstone protions that are hidden from sun and gather moss and algae because of humidity. Preservatives are also used to increase the longev
An alkaline solution of ammonia is used to clean the red sandstone. ASI uses a special biocidal treatment for the sandstone protions that are hidden from sun and gather moss and algae because of humidity. Preservatives are also used to increase the longev
An alkaline solution of ammonia is used to clean the red sandstone. ASI uses a special biocidal treatment for the sandstone protions that are hidden from sun and gather moss and algae because of humidity. Preservatives are also used to increase the longev