Gordillo’s Cal de Morón – Isidoro Gordillo Mesa

DESCRIPTION OF THE WORK

In 2011 the artisanal production of lime in Morón received an acknowledgment by the UNESCO, becoming registered within the list of programmes, projects and activities for the safeguarding of Heritage and declared Intangible Cultural Heritage of Humanity in its section regarding good practices. From mid 19th century, they manufacture high-quality lime in an artisanal way, unique in the world. Gordillo’s Cal de Morón selects the stone from the quarry, picking and differentiating between the different types, and they carry out an inherited technique which, today, is only carried out by this family. In Morón de la Frontera (Sevilla) there are important quarries of very pure limestone, its composition has a 98% of calcium carbonate. This natural richness is the first step to the quality of the final product. Lime is a natural product, with a production cycle that is very respectful with the environment. In the process of manufacture of lime, limestone is used (calcium carbonate [CaCO3]). When limestone is fired at high temperatures (above 900º), carbon dioxide (CO2) is released, transforming it into quicklime or calcium oxide (CaO), which will then need carbon dioxide (CO2) again to harden and become calcium carbonate again. Products: air lime putty, obtained from the process of firing the limestone in the wood-fired oven, quality CL90. Lime powder, resulting from the firing of limestone of a purity of up to 99% in calcium carbonate, selected from the quarry, at a constant temperature between 900ºC and 1000ºC, during about 15 days non-stop, in ovens of Arabic origin, using as combustible materials olive wood, pine, holm oak,…All the process is carried out in a traditional and artisanal way with complete respect for the environment. The result is a product of great creaminess, malleability and softness, speed curing and hydraulicity, without losing any resistance. Quicklime in clods: air lime putty, obtained from the process of firing the limestone in the wood-fired oven, quality CL90.Lime putty with an ageing effect: air lime putty, obtained from the process of firing the limestone in the wood-fired oven, quality CL90. It is a soft, dense and white paste, resulting of the firing of the same limestone as used for the other two products but aged in silos for over four years. Lime putty mortar: used for both exterior and interior finishes, made of a mixture of air lime putty, obtained from the process of firing the limestone in the wood-fired oven, quality CL90, and granulated aggregates of calcium carbonate (purity of over 90%), selected siliceous aggregates and inorganic pigments. It is executed as a first levelling layer since it has coarse uncoloured aggregates. After that, one or two layers are applied, depending on the sort of finish, made of lime mortar of a fine and smooth nature and a thickness of 5mm. Lime putty mortar is ideal for rough render coatings and re-jointing in rehabilitation and restoration works of historic buildings where identical mortars to those original ones are required, with the same characteristics and patinas of the old days.Hydraulic lime: lime mortar, used both for exteriors and interiors, made of a mixture of hydraulic lime NHL-3,5, obtained from the firing process of lean limestone, rich in aluminium, in a wood-fired oven, producing silicates, aluminates and iron-aluminates, with grounded aggregates of calcium carbonate and selected siliceous aggregates, cellulose fibre, styrene acrylic resins BASF under 5% according to DIN 1836, vegetal glue and natural additives.