In a message dated 7/27/02 10:12:00 AM Eastern Daylight Time, [log in to unmask] writes:
I'm also finding bits and pieces of coal in the mortar, anyone ever seen this before. I've seen burnt and unburned pieces of wood but never coal.
Coal is an occasional component in mortar. It is a natural, trace (<5%) component in masonry sands from areas with coal in the bedrock. Coal is common in the sands from some areas of AL, KY, OH, PA, WV, and VA. I've also observed coal fragments in historic mortars from buildings in regions without coal production. This coal is often associated with coal slag. In these instances, the coal and the coal slag are the residue from steam boilers. Coal-fired steam boilers were once common in houses, locomotives, ships, and steam shovels. We've also analyzed mortars that contain large quantities of coal or coal byproducts. The mortar used in one house in CT had anthracite coal as it's sand. Crushed bottom ash is also occasionally used as a sand. Black Beauty, Camel Black, and the other sand blasting sands are a component in some stuccos, concretes, and mortars. Sandblasting sand products do not have the proper grading to be used as masonry sands. They must be blended with other products.
Steve Stokowski
Stone Products Consultants
Building Products Microscopy
10 Clark St., Ste. A
Ashland, Mass. 01721-2145
508-881-6364 (ph. & fax)
http://members.aol.com/crushstone/petro.htm