Masonry Magazine September 2002 Page. 32
Stone
CUTTING
TRIMMING
STONE,
CUTTING
COSTS
BY TOM INGLESBY
The fabrication shops are well equipped for cutting limestone, granite and other 'rocks.' Taking some of that technology into the field makes the mason's job easier and less costly.
Cliff Maddock, co-owner of World Diamond Source, tests a stone cutting blade at their facility in Florida.
WHEN WE WENT ONSITE AT THE PENTAGON for the special report in August, we were impressed by the ability of Bybee Stone, Elletsville, Ind. and Masonry Arts, Bessemer, Ala., to rebuild the 60-year old building in material that had to meet exacting standards of historical accuracy. The limestone Bybee supplied came from fields, some near the sources of the original stone, that had already been shut down for the winter. Taking blocks of stone that were "just sitting around" and cutting them to reproduce the texture of the original, damaged façade's limestone required care and equipment suitable for the job.
Once the stone arrived at the Pentagon, as is always the case, some had to be "adjusted" with field cuts. Remember, the stone had been fabricated using drawings from 1942-which had been modified on a daily basis during the original construction according to contemporary reports. And even then, the drawings they first found were not for the elevation that was damaged but for a similar one on another part of the building. That put pressure on Masonry Arts to do onsite trimming with extreme care to prevent waste and assure fit while maintain historical visual accuracy.
During the research for the Pentagon series, we talked with some of the equipment and tool suppliers to Masonry Arts. One-World Diamond Source, Pompano Beach, Fla-provided the blades that allowed those custom cuts. As we were researching this month's feature on stone cutting, it was obvious that World Diamond Source could provide us, too, with valuable resources.
Matt Shrater, regional accounts manager for the mid-Atlantic, and Cliff Maddock, president and co-owner, with his brother, of World Diamond Source agreed to sit down for a discussion of blades for stone cutting. Here is what we learned.
"On the Pentagon, they were doing granite and limestone," recalls Maddock. "Masonry Arts buys a lot of seven-inch turbo blades from us and we have about 20 different bond hardness ratings for those blades. To cut a soft limestone, blue stone, or sandstone, something that is softer, and therefore more abrasive, you need a hard bond holding the diamond within the segment."
He adds, "If you have too soft of a bond when working on soft abrasive material, it's going to cut fine, it's going cut extremely fast, but you're going to prematurely wear the blade out. It's like rubbing your hand on the street-your skin is going to peel away. That's what a soft bonded blade does on soft material."
The opposite is true if you're cutting a hard material, then you need a soft bond. If you have too hard a bond when cutting hard material, the blade is not going to cut, it's going to deflect and bounce off the material.
What makes a stone blade different than a brick or block blade? "With a stone blade you have different grit or mesh sizes of the diamond," begins Maddock. "You have different diamond concentrations, different diamond grades, different bonds. You