History of Venetian Plaster

History of Making Slaked Lime  

The plaster we use is the highest quality available, and that is all done with the least expense to the environment. In brief, this is how the base is made.

The Pebble

Lime is an ancient, ecological, renewable, and highly resistant material. The first traces are lost to history and the oldest artefacts found are from the times of the Phoenicians and ancient Greeks. Lime is made from river pebbles, rich in calcium carbonate: a journey through tradition and technology, still amazing even today, they are transformed in to slake lime.

The Fuel

Just as in ancient times, even today wood is the fuel used for backing the pebbles in the furnace. Not a single tree is chopped down. By making the effort to collect the scraps from carpentry firms throughout the region, the enormous amounts needed are purchased and turned into sawdust. The dust is blown into the oven and burns without using gas, petroleum, coal or electricity. We might say Nature+Nature.

The Baking

Tradition and innovation combine in the backing process. Traditional brick barrel furnaces are still used, but the technology is fully computerized. An automatic control system oversees every stage of the process, from the moment the pebbles enter the top of the furnace to when they leave from the bottom, in a continuous-cycle process that lasts approximately one week. The temperature is kept stable by metering the addition of sawdust, and highly sophisticated laser probes cleanse the combustion fumes before they are released into the atmosphere.

The Extinguishing

The pebbles, crumbled by backing, are now quicklime, and will become seasoned slaked lime through a path beginning with extinguishing. Water is added to the quicklime to dissolve the pebbles and create a dense liquid that is filtered, before it is sent into the large seasoning tanks, to discard the unbaked portions that would otherwise jeopardize the product quality.

The Seasoning

Seasoning begins when a large tank, with a capacity of 500 tons, has been filled. Almost like a good wine, the slaked lime must rest for at least six months. This is the minimum time for the material to reorganize into the chemical structure of seasoned slaked lime.

The Slaked Lime

The slaked lime is now ready, but before it enters the manufacturing cycle it is micro-filtered once again, to make it creamy and remove the smallest impurities. Ready for manufacturing processes.