Loam-cake
Flat cores, made by simply spreading loam of a stiff nature on a plate in the oven. They may be made any thickness desired, and strengthened by thrusting within the mass a few iron rods. These cakes make excellent covering cores. See LOAM.
Loam-mill is any contrivance for mixing well together the ingredients of which loam is composed. The object is not so much to grind to a fine consistency as it is to thoroughly mix the clay and manure with the sand, so that every portion of the loam may be alike open in its nature. If the loam is ground too much by very heavy rollers, the clay becomes too intimately incorporated with the overground sand, the grains of which have been crushed into fine powder, resulting in a pasty mass which, when it yields its water, shrinks on the surface of the mould, leaving cavities and cracks which are difficult to correct, and always leave a map-like appearance on the casting. By retaining as much as possible the original coarseness of the ingredients the shrinkage spoken of is distributed equally throughout the surface, and is not noticed at all. Another evil which attends the use of all over-ground loam is, that, being less porous, the gases generated by the molten metal have greater difficulty in escaping in a legitimate manner, and hence force their way into the mould, creating great commotion, and sometimes carrying off portions of the mould surface, making scabs. See LOAM; VENTING.