To create a lime wash effect, you'll essentially be making a thin, paint-like coating using lime putty, water, and optionally, pigments. Here's how:
1. Gather Your Materials:
- Lime Putty: This is the key ingredient. Use mature lime putty for best results.
- Clean Water: Use clean, potable water.
- Lime-Stable Pigments (Optional): If you want to add color, make sure the pigments are compatible with lime. Avoid synthetic pigments. Natural earth pigments are a good choice.
- Buckets: For mixing.
- Whisk: For creating a smooth consistency.
- Protective Gear: Gloves and eye protection are essential when working with lime.
- Brush: A masonry brush is typically used for applying lime wash.
2. Prepare the Surface:
- The surface to be limewashed should be porous and free from any previous coatings (like acrylic paint) or loose debris. Lime wash needs to penetrate the surface to bond correctly.
- Dampen the surface lightly with water before application. This helps the lime wash adhere and prevents it from drying too quickly.
3. Mix the Lime Wash:
- The Basic Recipe: A traditional limewash consists of approximately equal parts lime putty and water.
- Mixing Process:
- Place the lime putty in a bucket.
- Gradually add water while whisking constantly.
- Continue adding water until you achieve a creamy, milk-like consistency. It should be thin enough to brush on easily but not so thin that it runs excessively.
- Adding Pigments (Optional):
- If using pigments, mix them with a small amount of water to create a slurry.
- Gradually add the pigment slurry to the lime wash, mixing thoroughly until the desired color is achieved. Remember that the color will lighten as the lime wash dries.
4. Apply the Lime Wash:
- Application: Apply the lime wash in thin, even coats using a masonry brush. Use long, overlapping strokes.
- Multiple Coats: Typically, 2-3 coats are needed for good coverage and durability. Allow each coat to dry completely before applying the next. Drying time can vary depending on humidity and temperature, but usually at least 24 hours between coats is recommended.
- Curing: Lime wash hardens through a process called carbonation, where it absorbs carbon dioxide from the air. This process can take several weeks. During this time, protect the surface from rain and direct sunlight.
Important Considerations:
- Safety: Lime is caustic and can irritate skin and eyes. Always wear protective gear.
- Application Conditions: Avoid applying lime wash in direct sunlight or during very hot weather, as it can dry too quickly and lead to cracking.
- Traditional vs. Modern: While the recipe above outlines traditional lime wash, some modern variations include additives like casein or linseed oil to improve adhesion and durability. However, these additions may alter the breathability and overall effect of the limewash.
- Experimentation: It's always a good idea to test the lime wash on a small, inconspicuous area before applying it to the entire surface. This allows you to check the color and consistency.
