Instructions for Stucco Veneziano
Step-by-step instructions Stucco Veneziano
1) If lime plaster, cement plaster or gypsum-cement plaster is present as a plaster base, the basic filling can be started immediately. However, if you do not have any mineral substrates, such as dispersion paints, plasterboard, glass, tiles, MDF and also reinforced concrete, etc., prime the surface with an adhesive primer. Adhesion primer with marble grains must dry for at least 12 hours. Adhesion primer with vegetable casein can also be used wet-on-wet. On top of this comes a fine layer of creative plaster, or on tiles first a lime adhesive plaster with embedded reinforcement fabric and then a layer of creative plaster.
2) Now apply the primer (without colour pigments). The material must be stirred thoroughly beforehand. If necessary, up to 1.5 % water can be stirred in. Apply so much that the plaster primer is nicely covered. It is best to use a smoothing trowel with a rigid blade. The consumption for the first coat is approx. 1000-1300 grams/m² creative plaster or approx. 700 grams/m² stucco Veneziano, starting from a substrate with an adhesive primer. The base coat, also called concealed coat, with Creative Plaster forgives small unevennesses. If the first layer is filled with Stucco Veneziano, an exactly smoothed surface should be given. Creative plaster as a basic filler has the advantage that a more capillary effective build-up of the coating is achieved, because the largest grain size of creative plaster is 500 µm and of stucco Veneziano only 32 µm. This means that more air humidity is absorbed from the rooms. Drying time for the first layer: 8 to 12 hours, depending on temperature and humidity.
3) The putty is now coloured and left to stand for 2-3 hours. This colouring can also be done the day before. For details on colouring, see below under Dry colours and coloured doughs. From now on the Venetian smoothing trowel is used. In order to have enough time to apply the putty, the whole surface is pre-wetted with a spray bottle until the plaster is saturated. However, there should be no more water on the surface. For the second layer you need approx. 350 grams/m² Stucco Veneziano. This layer should cover the first so that a uniform colour is visible. Work with feeling and do not apply too much pressure. The drying time is about 3-4 hours. Depending on the time schedule or size of the project, you can also continue the next day.
4) For the third layer you need approx. 150 gram/m². The surface is pre-wetted again. With little material on the trowel, rub the surface at a flat angle with moderate pressure so that the lime crystals are pressed together nicely. It starts to shine; in the case of matt areas, a little more material should be applied. Afterwards, one can see the marbling. Depending on how satisfied you are with the result, a fourth coat can be applied after a drying time of 3-4 hours. It can happen that in some places too much compaction occurs and then the material unrolls. Roughen these imperfections with an abrasive fleece, reapply the material and compact. My recommendation: If for the third layer the filling compound is mixed with 5% Venetian soap, and if necessary with a little water, it will become much smoother and there will be hardly any material unrolling. To increase the shine, after a drying time of two to three hours, the inside corners should also be dry, the surface is coated with Venetian soap and smoothed with pressure. The soap coating can also be applied the following day. The handling of lime products is a matter of practice for everyone. Stucco Veneziano is sensitive to acids such as vinegar and fruit acid or certain cosmetics in the bathroom. The surfaces in these areas must be protected with wax. The colour intensity is increased by the waxing and the water rolls off. This wax coating can be repeated annually. However, the surface should first be cleaned with a Venetian soap solution. Details on the wax coating can be found below.
Dry paints and color pastes
Up to 10 % pigments (by weight) can be stirred into the putty. The lime cannot bind more and chalking would occur. If the dry paints, also called pigments, are stirred into the putty, a beautiful coloured mass is created. However, there is a high probability that pigment stains will appear, i.e. some pigments will be left behind in the form of drivers or traces when filling the compound. This does not necessarily have to be a disadvantage, it can also be seen as a nice side effect. However, if you want to avoid these pigment spots, prepare a coloured dough. This is how it works: For 1000 g pigments approx. 800 ml liquid are used (160 ml wetting agent and 640 ml water). Pour the liquids into a container and add the pigments, stir well with a spatula or spoon and grate; crush lumps at the edge of the container. It is best to make a note of the mixing recipe in order to be able to restore the same shade. Allow to soak for 3 hours and then mix this dough into the putty. Pigments have the highest colour intensity and set no limits to your creativity. Only use lime-compatible pigments.
If chrome oxide green, cobalt blue, titanium white or similar hard pigments are processed, a Venetian PVC smoothing trowel is used for compacting.
Wax coating and Venetian soap
The transparent Punic wax or beeswax balm is applied very thinly with a Venetian smoothing trowel. The wax layer must be very thin. After a flash-off time of 1-2 hours you can polish with a microfibre cloth. A polishing machine can also be used for large surfaces. Two to three coatings make the wall almost waterproof and the coating still remains open to diffusion. The intermediate drying time between the coatings should be 30-60 minutes for punic wax and up to 8 hours for beeswax balm. For high-gloss the Venetian soap is used as described above in point 4. Venetian soap is also used on the outside. Leave the last coat of Venetian stucco or Marmorino to dry for 2 hours, then apply Venetian soap with a Venetian smoothing trowel and remove the excess. Lime soap is produced on the fresh lime. This thin layer makes the coating water-repellent and thus protects against acid rain, which would otherwise transform the lime into plaster and destroy it. Polishing is done with a trowel or a microfibre cloth.
Stucco Veneziano is a natural white filler for use in decorative wall design. Due to its high alkalinity, it is resistant to moulds and, due to the porosity of the lime, highly permeable to water vapour diffusion.
Ingredients: Marble lime [Ca(OH)²], marble powder [CaCO³], water, cellulose and linseed oil.
Yield: approx. 1200 g/m² for 3 layers; depending on substrate and application also more consumption possible!
Specific weight: approx. 1.31 kg/l
PH value: 12.5
Storage conditions: Frost-free and in closed containers, covered with a PVC film and a layer of water, durable for many years.
Safety instructions: R36/38: Irritating to eyes and skin.