Quick Answer
Essential tools for earth plaster application include lime-based mixing buckets, trowels, sponges, and a mixing stick for preparing the plaster slurry, along with a plaster float for smoothing the surface and a mudding knife for fine-tuning.
Preparing the Workspace
When applying earth plaster to a cob building, it is crucial to have a clean and level workspace. Start by sweeping the area clear of debris and dust, and then lay down a protective covering to prevent damage from spills or splatters. A 3/4-inch (19mm) thick layer of old carpet or a similar material works well for this purpose.
Mixing and Applying the Plaster
To mix the earth plaster, use a lime-based bucket with a capacity of at least 5 gallons (19 liters). Add 1 part lime putty to 3 parts earth mixture, and then stir in 1/4 cup (60ml) of water per 5 pounds (2.3kg) of mixture. Use a mixing stick to blend the ingredients until they form a smooth, consistent paste. Apply the plaster using a trowel, starting at the bottom of the wall and working your way up. Use a sponge to smooth out the surface and remove any excess material.
Finishing Touches
Once the plaster has been applied, use a plaster float to smooth out the surface and remove any air pockets or imperfections. This will help create a durable and long-lasting finish. For fine-tuning, use a mudding knife to feather the edges and blend the plaster into the surrounding surface. Work in small sections, about 4 feet (1.2 meters) square, to maintain even coverage and prevent the plaster from drying out too quickly. Allow the plaster to dry completely before applying additional coats or finishes.
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