Can You Seal Air Dry Clay? A Comprehensive Guide
Yes, you absolutely can and should seal air dry clay. Sealing air dry clay protects it from moisture, making it more durable and preventing it from cracking or crumbling over time.
Understanding Air Dry Clay and the Need for Sealing
Air dry clay, unlike traditional clay, hardens by evaporation of water rather than firing in a kiln. This makes it a convenient and accessible material for crafting and sculpting. However, this very property leaves it vulnerable. Unsealed air dry clay remains porous and susceptible to absorbing moisture from the environment. This absorbed moisture can lead to:
- Softening and Weakening: The clay can revert to a pliable state, losing its shape and structural integrity.
- Cracking and Crumbling: Fluctuations in humidity can cause the clay to expand and contract, leading to cracks and eventual disintegration.
- Mold and Mildew Growth: The porous nature of unsealed clay makes it an ideal breeding ground for mold and mildew in humid conditions.
- Paint Peeling and Chipping: Paint applied to unsealed clay doesn’t adhere well and is prone to flaking.
Therefore, sealing air dry clay is crucial for preserving its longevity and maintaining the aesthetic appeal of your creations.
Choosing the Right Sealer
Selecting the appropriate sealer is paramount to achieving the desired results. Several options are available, each with its own set of advantages and disadvantages.
Types of Sealers
- Acrylic Sealers: These are water-based sealers that offer excellent protection against moisture and are relatively easy to apply. They are available in various finishes, including matte, satin, and gloss.
- Polyurethane Sealers: Known for their durability and resistance to water, polyurethane sealers provide a hard, protective coating. They are often used for projects that require a high level of water resistance. However, they can sometimes yellow over time.
- Mod Podge: A popular all-in-one sealer, glue, and finish, Mod Podge is suitable for a variety of craft projects. It provides a decent level of protection against moisture, but it may not be as durable as dedicated sealers.
- Resin: For a completely waterproof finish, resin is an excellent option. However, it requires specific handling and safety precautions, making it less suitable for beginners.
- Varnish: Similar to polyurethane, varnish offers good protection and is available in different finishes. Choose a water-based varnish for easier cleanup.
Factors to Consider When Choosing a Sealer
- Project Type: The intended use of your clay creation should influence your sealer choice. For example, items that will be exposed to water require a more robust sealer like polyurethane or resin.
- Desired Finish: Consider whether you prefer a matte, satin, or gloss finish.
- Application Method: Some sealers are easier to apply than others. Consider your comfort level with different application methods, such as brushing, spraying, or dipping.
- Cost: Sealer prices vary depending on the type and brand.
Applying the Sealer
Proper application is essential for achieving optimal results.
Preparation
- Ensure the Clay is Completely Dry: Before applying any sealer, ensure that your air dry clay project is completely dry. This may take several days, depending on the size and thickness of the project.
- Clean the Surface: Remove any dust or debris from the surface of the clay using a soft brush or cloth.
- Work in a Well-Ventilated Area: Some sealers can release fumes, so it’s important to work in a well-ventilated area.
Application Techniques
- Brushing: Use a soft-bristled brush to apply the sealer in thin, even coats. Avoid applying too much sealer at once, as this can lead to drips and runs.
- Spraying: Spraying provides a more even and consistent coverage. Use light, overlapping strokes and maintain a consistent distance from the surface.
- Dipping: For small items, dipping can be a convenient option. Submerge the item in the sealer and then allow any excess sealer to drip off.
Number of Coats
Apply at least two coats of sealer for optimal protection. Allow each coat to dry completely before applying the next. Three or more coats may be necessary for items that will be exposed to water or heavy use.
Troubleshooting Common Sealing Problems
- Bubbles: Bubbles can form if the sealer is applied too thickly or if the clay is not completely dry. To prevent bubbles, apply thin coats and ensure that the clay is fully dry before sealing.
- Streaks: Streaks can occur if the sealer is not applied evenly. Use a soft brush or spray gun to apply the sealer in consistent, overlapping strokes.
- Yellowing: Some sealers, particularly oil-based polyurethane, can yellow over time. Choose a water-based sealer to minimize the risk of yellowing.
- Tackiness: Tackiness can occur if the sealer is not allowed to dry completely. Ensure that each coat is fully dry before applying the next.
Frequently Asked Questions (FAQs)
FAQ 1: Will sealing air dry clay make it waterproof?
No, sealing air dry clay will make it water-resistant, not necessarily waterproof. While sealers provide a protective barrier against moisture, prolonged exposure to water can still damage the clay. For truly waterproof items, resin is a better choice.
FAQ 2: Can I use hairspray to seal air dry clay?
Hairspray is not recommended as a sealer for air dry clay. It may provide a temporary shine, but it offers little to no protection against moisture and can become sticky or yellow over time. Use a dedicated sealer for best results.
FAQ 3: How long does it take for the sealer to dry?
Drying time varies depending on the type of sealer and the ambient humidity. Generally, allow at least 24 hours for each coat of sealer to dry completely. Refer to the manufacturer’s instructions for specific drying times.
FAQ 4: Can I paint air dry clay before sealing it?
Yes, you can and often should paint air dry clay before sealing it. Painting allows you to add color and detail to your project. Ensure the paint is completely dry before applying the sealer. Use acrylic paints for best results, as they adhere well to air dry clay.
FAQ 5: What type of paint should I use on air dry clay?
Acrylic paints are the best choice for air dry clay. They are water-based, durable, and readily available. Other options include tempera paint and watercolors, but they may require more coats and may not be as durable as acrylics.
FAQ 6: Can I use air dry clay for food-related items?
No, air dry clay is not food-safe, even when sealed. It is porous and can harbor bacteria. Avoid using air dry clay for items that will come into contact with food or beverages.
FAQ 7: How can I prevent my air dry clay from cracking?
Several factors can contribute to cracking. Preventative measures include: drying the clay slowly, avoiding drafts, using a high-quality clay, and ensuring the clay is evenly thick. Also, sealing the clay after it’s dry helps prevent moisture absorption, which can lead to cracking.
FAQ 8: Can I re-seal air dry clay if the initial seal wears off?
Yes, you can re-seal air dry clay if the initial seal wears off. Clean the surface of the clay and apply a fresh coat of sealer.
FAQ 9: Is Mod Podge a good sealer for air dry clay?
Mod Podge is a decent, multi-purpose option, but may not be as durable as dedicated sealers. It provides moderate protection against moisture and is easy to apply. It’s a good choice for projects that won’t be exposed to a lot of wear and tear.
FAQ 10: Can I use a sealant spray instead of brushing?
Yes, using a sealant spray is a perfectly acceptable and often preferred method. It provides an even, consistent coat and reduces the risk of brush strokes. Ensure you work in a well-ventilated area and follow the manufacturer’s instructions.
FAQ 11: Will sealing air dry clay make it stronger?
Yes, sealing air dry clay will make it somewhat stronger. The sealer provides a protective layer that helps to prevent the clay from absorbing moisture and becoming brittle.
FAQ 12: What are some alternatives to commercial sealers?
While commercial sealers are generally recommended, some crafters use clear nail polish or even multiple coats of acrylic varnish as alternatives. However, these options may not provide the same level of protection and may require more frequent reapplication. Always test a small, inconspicuous area first.