Veneziano Application

Venetian Plaster made with lime and crushed marble - Page 3 of 7

Masking
Always mask before priming and plastering. Good masking will result in a razor sharp line between the plaster and anything adjacent. When masking, be sure to buy the right tape. Blue tape is the best. Don't use low tack blue tape. It generally falls off trim under its own weight. White tape is too sticky and can either leave a sticky residue on the trim or tear off the paint or varnish to which it sticks. If using white tape, make sure it's not exposed to the sun, otherwise it will really stick to the trim. On remodels, sometimes the wood is very lightly varnished and even blue tape can peel off the finish. In this case, use low tack blue tape. When masking, use a hand masker that applies paper directly to the tape. Mask (stick tape) about 1/16" away from the wall. Make sure when plastering not to get too much on the tape. This will make it difficult to remove the tape later.

Means of application / tools:
There are two ways to hold the plaster when troweling, either with a hawk (a square foot of metal with a handle at the bottom) or with a mud pan (an elongated metal container). The hawk requires a trowel or spatula and the mud pan requires a spatula (or mud/plaster knife). The trowel is our favorite for Veneziano. Spatulas and mud pans are fine too. It's a matter of preference.

The trowel or spatula should be stainless steal and have slightly rounded corners. The reason for stainless steel is that it won't rust and leave rust lines in the plaster. If it isn't stainless steel, just be very sure to dry the trowel when not in use. There are trowels with rounded corners specifically manufactured for Venetian Plaster; or you can go to almost any hardware store and purchase a trowel and sand down the edges. The reason for this is that if you have sharp edges, the trowel can leave distinct lines on the plaster. Hawks and mud pans can be bought at most hardware stores.

When troweling, if the trowel or spatula are consistently leaving unwanted lines in the plaster, make sure there's nothing stuck on the trowel edge and if it persists, the metal might be dinged, scratched or the corners may not be smooth. In these cases; sand the edged of your trowel/spatula with 220-grit sandpaper or a sanding sponge.

After extensive use of the trowel or spatula, the edges can become razor sharp. Be very careful handing the tools. Also, always be sure to thoroughly clean all your tools to prevent rust and dried plaster chunks from getting into your walls.

Plastering/application:
Before you start, make sure everything is masked off and the tape is adhering to the walls/trim. Make sure you have the appropriate equipment including trowels, small spatulas (or something that will get into hard to reach areas), a box of latex gloves, rags, goggles (to avoid getting plaster in your eyes), and a spray bottle of water. You don't want to stop in the middle of a wall to look for equipment and let it dry out before you finish.

Minimum application is two coats. You can apply as many coats as you want between drying. 'Burnishing' will be discussed shortly.

The color and texture of the first layer will determine your final outcome. Veneziano is applied in "skim" coats. When burnished, it becomes almost translucent and smooth revealing underneath layers.

Always plaster walls from the top to bottom. There are essentially two ways of plastering: in random diagonal crosshatched or criss-cross vertical and horizontal strokes. Ideally, the finished product should look natural, like something that did not require artificial means of application, in other words: no obvious trowel marks. However, certain techniques call for just the opposite, and you would need to override this training and make trowel marks.

One gallon covers approximately 130-180 square feet. Remember, you need at least two coats. It should be mixed one day prior to application, or at least five hours before. Otherwise the plaster will be too watery to easily trowel. This is because lime is thixotropic, meaning it gets thinner or runnier as it is agitated. This applies to over working it on the hawk as well. Of course, for smaller amounts of plaster to add splashes or layers of color, this does not apply.

VENEZIANO APPLICATION CONTINUED
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