As early as the 19th century, architects began adopting natural or Roman cement for facade decorations. The molding technique, whether prefabricated or not, already well-established with plaster, quickly evolved with the use of natural cement, an ideal material due to its durability and suitability for mass production.
Solution
PROMPT natural cement enables the creation of original cast decorations with a minimal number of molds and in record time (excellent turnaround). With the rapid setting of PROMPT natural cement by Vicat, it's possible to demold between 1 to 3 hours after pouring while maintaining a smooth surface appearance. Aesthetically, PROMPT natural cement offers castings with colors suitable for both old and new substrates, allowing for the creation of decorative and unique pieces.
Technique
First and foremost, it's important to prepare the mold. Its surface should be clean, so apply a special wax to facilitate demolding.
Next, prepare the PROMPT natural cement mortar using an electric mixer. Several steps are involved :
- The outer layer, which provides the surface appearance, should have a creamy consistency and be brushed onto the mold's surface
- The preparation of the inner mortar, which forms the body of the casting, depends on its volume (small, medium, large)
Casting is a true art, and there are numerous ways to execute it. Dosages, sand type, and granulometry, as well as its workability, can vary: from firm mortar to liquid mortar, from a 2:1 ratio to a 1:2 ratio.
For placing the mortar, pour the PROMPT natural cement mortar into the mold and ensure compaction through light vibration. Scrape off excess mortar. Once setting begins, do not touch the surface.
For demolding, wait approximately 1 hour for a simple shape, and up to 3 hours for a more complex shape. Demolding time influences the surface shade. The color will be more ochre if demolding is done quickly and in humid conditions, whereas demolding after several hours will result in a grayer shade. These nuances can be mitigated by adding the appropriate filler or pigments.
Early-age strengths are quite high. However, a damp curing process for at least two weeks is essential to optimally hydrate the surface of the PROMPT natural cement mortar.
PROMPT natural cement is used in the production of numerous architectural details on European facades (France, United Kingdom, Italy, Germany, Czech Republic, Poland, etc.).
It's also frequently employed in landscaped gardens for creating features like borders or balustrades.
Using a mortar of PROMPT natural cement by Vicat for creating cast moldings offers several advantages :
- Rapid and adjustable setting time
- Cost savings due to improved mold rotation
- Decorative and original
- Colors suitable for both old and new substrates
