Improvements relating to the production of vermiculated appearance in artificial stone and like building materials

摘要

217,812. Delaney, J. H. Sept. 25, 1923. Porous artificial stone resembling natural travertine is produced by subjecting the surface of a plastic composition to the action of a gas so as to produce a vermiculated effect. A reagent such as calcium carbide is applied to the surface of the mould so that gas is generated by the contact of the wet composition. The mould surface may be provided with grooves arranged in any desired pattern, into which the calcium carbide is placed. Wall surfaces &c. may be treated in situ while still plastic and in this case smooth or grooved surfaces are applied to confine the gas. After the composition has hardened the residue of the gas-generating agent may be washed from the surface.