Venetian Plaster

Venetian plaster technique

• By using a stir stick, the Venetian plaster has to be mixed thoroughly. A practice board has to be used to preview the technique and color combination before embarking on the project.
• Load Venetian plaster on a steel trowel. The corners of a steel trowel is rounded with 100-grit sandpaper or a file to decrease edge marks during application. There must be another 400-grit sandpaper for a more smooth edge.
• Begin at the corner of the room and apply the Venetian plaster to the wall and hold the steel trowel at a 15-30 degree angle.
• The Venetian plaster is thinly spread across the surface using long and short random strokes. The initial wall surface cannot appear through in some areas. The steel trowel can be wiped off to avoid dried Venetian plaster from producing an effect over the application.
• The Venetian plaster can be allowed to dry for 4 hours before applying the second coat.

Second coat

• The Venetian plaster can be loaded on a steel trowel.
• Initializing at the corner of the room, a thin coat of Venetian plaster has to be applied to the wall. The steel trowel has to be held at 60-90 degree angle. The overlapping strokes that have to be used are long and short.
• The voids and recessed areas has to be filled and the original wall surface covered completely.
• Any edge marks or high spots with the trowel can be smoothed away.
• The Venetian plaster must be allowed to dry for 24 hours before topcoating or burnishing.

Topcoat

The Venetian plaster topcoat and Premium Plus with style Venetian plaster topcoat is used for a washable and satin-sheen finish in high traffic or excessive moisture areas. The surface must not be burnished or polished before or after the application of topcoat. A clean and flexible 4" or large steel trowel is used to spread the Venetian Plaster topcoat across the surface and the trowel has to be held at an angle of 60-90 degrees. Long and short overlapping strokes. This topcoat has to be spread onto the surface thinly and puddling in the recessed areas has to be avoided, so that there is a milky appearance when dry. This has to be dried for nearly 24 hours.

Burnishing

• The Venetian plaster has to be dried for 24 hours. The surface has to be burnished within 7 days of application.
• Using 400 or 600 grit sandpaper, the surface has to be rubbed in a circular motion till the desired look is obtained. For large areas , a power sander has to be used.
• The burnished surface has to be wiped with a water dampened rag to get rid of any plaster dust.
• The flat side of a clean steel trowel has to be used for a better polished look. The heat and friction due to rubbing creates a defined and glossy appearance.

Applying Venetian plaster

• The most important and overlooked step is to ensure that the substrate is smooth, flat and level.
• The voids and high areas will result in blemishes to polish more than the surrounding area.
• Any trim or adjoining walls not receiving plaster have to be taped off.
• The wall has to be primed with an oil based primer or other approved primer.
• The step isolates the substrate from the Venetian finish and suction of the finish material across the surface is confirmed.

Applying base coat

• Generally, a Marmorino type plaster is applied with a trowel in a single coat.
• Some Venetian plasterers have to specify an alternative liquid brush on or roller applied base coat.
• The base coat has a coarse or sanded tooth for the Venetian plaster to stick to.
• Dry and sand lightly with 100 grit paper and block to knock down any areas.

Venetian finish coat

• Initially, first apply a coat of Venetian plaster using a stainless steel trowel using short random strokes. The edges must not be left dry.
• Wet material has to be applied to wet material.
• The first coat of Venetian finish has to be dried to 70%.
• The second coat of Venetian plaster has to be applied with random strokes having a wet edge.
• When the second coat is wet, the third thin finish coat of material has to be applied.

Polishing

• Before the final coat dries, the finish has to be polished with the stainless steel trowel in the application. The trowel has to be kept clean and burr free.
• To have a scratch free finish, the trowels blades have to be polished with 800 and 1000 grit sandpaper. This is necessary also for new factory polished blades.
• A smaller trowel provides more pressure for polishing.
• The surface has to be polished, while the finish applicator is applying the final finish coat.