The technique is limited to small encrustation and to uncomplicated shapes, which require only a few cuts. A problem also arises in correctly aligning the two halves and the cardboard gasket required to replace the thickness sawn away by the blade. This problem is compounded when more than one cut is made. When the mold is cut with a saw, the seam flashing is very noticeable. If X-ray facilities are available, some of the problems of casting natural molds can be overcome.
Radiographs reveal the shape of the object and the extent of the corrosion.
In certain encrustation, it is possible to use a pneumatic air chisel to cut openings into the distal ends or key points of an object. Through these holes, the corrosion residue can be washed out and the casting compound poured. Alternatively, the air chisel can be used to inscribe a line along or around an encrustation. By hitting along this line with a chisel and a hammer, the encrustation can be broken in a predetermined manner. Simple encrustation are easily opened and cast in this way.