The physical scape of Oakland Cemetery is bombarded daily by the elements. Acid rain, air pollution, wind, falling tree limbs, vandalism and a myriad of other natural and manmade can cause erosion, cracks and the general failure of the stone itself. These failures can leave a void in the stone exacerbating the disintegration of the monument. There a multiple procedures to repair these issues, the two most popular of which are a simple patch or the more time consuming, “Dutchmen.”
The simple patch involves a cementitious, mineral based mortar that is applied as a fill to the crack or chip. At Oakland the Restoration Staff uses Jahn mortars and best practices recommended for this specific brand. To add the patch: the stone should be moistened with no pooling water and a base coat of mortar about the consistency of peanut butter applied to the surface at an eighth of an inch thick. Immediately after the peanut butter coat is applied, a drier coat of mortar should then be built up just above the natural, undamaged surface of the stone.
The wetter peanut butter coat creates a bond to the stone for the drier coat, which prevents shrinkage and the separation of the mortar from the stone. After the drier coat has partially set, the mortar can be shaped to the profile and texture desired.
The Dutchmen is a bit more complicated than the general patch. The idea behind it is to cut out an impacted or damaged stone and replace it with similar stone plug. It requires attention to detail and near exact match in terms of color, shape and texture of stone.
Once a “matching” stone is found, one must cut around the damaged area in the monument and down to a sound depth in the damaged stone. At this point the plug from the matching stone should be cut and shaped to fit the area removed from the damaged stone. Using pins and epoxy, the plug can then be secured to the stone. After the epoxy dries and the plug is secured, it can now be tooled to the desired profile and texture of the original monument. A more decorative piece may be tooled prior to installation.
The Dutchmen is considered the best possible repair for damaged stone, because it replaces stone with stone and should be used if and when at all possible. The typical repair procedure used by Oakland’s Restoration Staff is the patch. The difficulty in finding matching stone, and the cost and time consuming nature of the Dutchmen repair method do not make it a good fit for Oakland’s restoration needs.