What Can You Seal A Clay Ashtray With?

Clay ashtrays have been around for decades as useful receptacles for collecting ash and cigarette butts. Made from ceramic clay and fired in a kiln, ashtrays provide an inexpensive, durable, and attractive way to contain the mess and odor of smoking indoors or outdoors.

Sealing a clay ashtray serves multiple purposes. Applying a sealant creates a protective barrier on the surface of the clay that prevents scratching, staining, and absorption of odors and flavors from cigarettes. It also provides an impermeable coat so ashes, moisture and oils do not penetrate the porous clay material over time. Sealing fills in tiny holes and crevices to help keep the ashtray clean. Lastly, some sealants like varnishes or lacquers can enhance the ashtray’s appearance and give it a glossy finished look.

Glazes

Glazes are vitreous coatings that provide a smooth, non-porous surface and pleasing aesthetic to ceramic wares like ashtrays. They are made from a mixture of silica, flux, and alumina that melt and fuse to the clay body during high-temperature firing in a kiln.

Common glazes used for ashtrays include:

• Glossy glazes – These have a shiny, glass-like surface and enhance colors.
• Matte glazes – These have a smooth but non-reflective surface and muted colors.
• Crystalline glazes – Tiny crystal formations emerge during firing for a complex visual texture.

Advantages of glazing ashtrays include:

• Makes the surface non-porous and easy to clean.
• Seals and protects the clay from damage.
• Adds decorative colors, textures, and effects.
• Strengthens the ashtray and prevents scratching/chipping.
• Provides a finished look and feel.

Varnishes

Varnish is a common sealing choice for ceramic and clay projects. Some types of varnish that work well on ashtrays include polyurethane, spar urethane, and epoxy resin varnish.

The main benefits of using a varnish are that it seals and protects the ashtray, provides a smooth and durable finish, and enhances the look of the clay’s natural colors. Varnish creates a transparent, water-resistant coating that prevents staining from cigarette ash and smoke. It also makes the ashtray easier to clean.

Potential downsides are that some varnishes can yellow or darken over time when exposed to UV light. The varnish finish may also chip or scratch if not applied properly in smooth, thin layers. Some varnishes give off strong fumes as they cure and require proper ventilation. It’s important to choose a varnish specifically formulated for ceramics/clay rather than wood.

Waxes

Beeswax is a popular choice for sealing clay ashtrays. It provides a natural satin finish and is easy to apply. Beeswax works well as a sealer because it penetrates the porous clay surface. This helps fill in small cracks and inconsistencies in the clay. Beeswax seals are also lightly flexible, which helps prevent cracking if the clay expands or contracts slightly due to temperature changes.

Other waxes that can be used to seal clay ashtrays include paraffin wax, carnauba wax, and bayberry wax. Paraffin wax is derived from petroleum sources, while carnauba wax comes from the leaves of a palm tree. Bayberry wax is harvested from the fruit of the bayberry shrub. All of these waxes can be melted and brushed or dripped onto the baked clay surface to seal and protect it.

The main benefits of wax seals on clay ashtrays are that they provide a soft, low-luster finish and they are gentle on the clay surface. Wax seals are easy to apply, durable, and can be easily renewed by applying another thin coat of melted wax when needed. The waxes absorb well into porous baked clay. Wax seals are food-safe and heat resistant. They help protect the surface from damage caused by exposure to liquids and abrasion. Overall, beeswax and other waxes are excellent options for sealing unfinished clay ashtrays.

Oils

Oils like mineral oil, olive oil, and coconut oil can be used to seal clay ashtrays. When choosing an oil, opt for a food-safe one like coconut or olive oil if the ashtray will come in contact with food. Food-safe oils are non-toxic.

Oils are applied by lightly rubbing the oil over the surface of the baked clay piece. Allow the ashtray to soak up the first coat of oil, then wipe away any excess. Let the piece air dry for 24-48 hours before applying a second coat. Additional coats, up to 4-5 total, can be applied for a higher sheen finish.

The main drawback of sealing with oil is durability. Oils provide minimal surface protection, so the finish can scratch or wear away with regular use. Oils should be reapplied every few months to maintain their protective properties. So while oils give a beautiful natural luster, they require more maintenance than other sealants.

Epoxy Resins

Epoxy resins are a popular choice for sealing clay ashtrays. When cured, epoxy forms a high-gloss, durable, plastic-like coating that is scratch, stain, and heat resistant. Epoxies come in two parts – resin and hardener – which must be mixed together according to manufacturer’s instructions before use.

For ashtrays, a table top coating epoxy is recommended as it is designed for coating small craft items. These are available in various finishes from glossy to satin. Make sure to choose an epoxy rated for high temperatures if the ashtray will be used for burning cigarettes.

Epoxy gives off fumes during the curing process so work in a well-ventilated area. It is important to follow the proper mixing ratio and allow the full curing time stated on the package directions to ensure the epoxy fully hardens and the ashtray can be safely used.

Epoxy resin kits suitable for coating ashtrays can range from $15-$50 depending on the brand and quantity. Buying larger kits is more economical if doing multiple pieces.

Polyurethanes

Polyurethane is a popular sealant and finish in many crafts and home improvement projects. Polyurethanes are valued for their durability, flexibility, water resistance, and fast drying times. When used on ceramic and clay surfaces, polyurethanes provide a clear, glossy, and protective coating that enhances the appearance and durability of the piece.

Some of the key benefits of using polyurethane to seal clay and ceramic items include:

• Durability – Polyurethane forms a tough, abrasion-resistant film on the clay’s surface that holds up well to regular handling and use.
• Protection – Sealing with polyurethane can help protect ceramic and clay surfaces from moisture, oils, and other contaminants that may stain or discolor the piece over time.
• Enhanced beauty – Polyurethane has a crystal clear finish that enhances the natural colors and textures of the clay or ceramic beneath it.
• Versatility – Polyurethane can be used on both bare and painted clay surfaces.

However, polyurethane does come with some toxicity concerns, mainly due to the isocyanates present in some formulations. Isocyanates can irritate eyes, skin, and lungs during application. When working with polyurethane sealers, it’s essential to work in a well-ventilated area and wear appropriate gloves and a respirator mask to minimize exposure.

Water-based or low-VOC polyurethane formulas are safer options that minimize risks from isocyanate exposure. Regardless of the type used, be sure to follow all label safety precautions closely.

Lacquers

Lacquers are a popular choice for sealing ashtrays. There are two main options for applying lacquer:

Spray Lacquers vs Brushing Lacquer

Spray lacquers provide an even, smooth coat but require spraying outside with proper protective gear. Brushing lacquers are simpler to apply but can create brush stroke marks.

Pros and Cons of Lacquer Seals

Pros:

• Dries fast, so multiple coats can be applied in one day
• Creates a durable, protective layer
• Enhances beauty of the clay surface with a glossy look

Cons:

• Toxic fumes require good ventilation
• Surface requires sanding between coats
• Difficult to repair if damaged without reapplying entire finish

Shellacs

Shellac is a natural resin that comes from the secretions of the lac beetle. It has been used for centuries as a sealant for wood products. Shellac can also be used to seal and finish clay projects, providing a nice glossy coat.

There are several methods for applying shellac to an ashtray or other clay piece:

• Brushing – Using a high quality natural bristle brush, apply multiple thin coats of shellac, sanding lightly between coats.

• Padding – Soak a lint-free cloth or pad in shellac and rub it gently over the surface to build up thin layers.

• Spraying – Shellac can be thinned with denatured alcohol and applied with a spray gun for an even coat. Multiple light coats are recommended.

When using shellac for indoor pieces like an ashtray, there are no major limitations. It provides good moisture resistance while still feeling natural. For outdoor pieces that will be exposed to weather, shellac is not the best choice as it can degrade over time. Indoor use is recommended for shellac finishes.

Overall, shellac can provide a beautiful natural gloss finish for clay projects. Just be sure to apply multiple thin coats for the best results.

Conclusion

When selecting a sealant for a clay ashtray, there are several good options to consider. Glazes, varnishes, waxes, oils, epoxy resins, polyurethanes, lacquers, and shellacs can all be used to effectively seal the porous clay surface.

Glazes are a popular choice as they bond permanently to the clay and create an impervious glassy surface. They come in various colors and finishes. Varnishes are also a good option, providing a durable clear finish. Waxes and oils provide protection with a softer, low-sheen look.

For the most durable, long-lasting seal on an ashtray, an epoxy resin is recommended. Epoxy fully penetrates the clay and creates an incredibly strong, waterproof barrier. Polyurethane is another excellent choice for durability and protection. Multiple coats of varnish or lacquer also seal well. When applying any sealant, make sure the clay is fully dry first.

In summary, epoxy resins and polyurethanes provide the most robust sealing for clay ashtrays, but varnishes, lacquers, glazes, waxes and oils can also work effectively. Always test sealants on sample pieces first. With the right sealant and proper application, an ashtray can be made fully functional and given lasting protection.