What Do You Coat Clay With To Make It Shiny?

Clay is a common material that has been used for pottery, sculpture, and decoration for thousands of years. The unique plasticity of clay when wet allows it to be molded into endless shapes and forms. When fired at high temperatures, clay undergoes a permanent physical and chemical change, enabling it to become hard and durable while retaining its formed shape.

A smooth, shiny surface is often desired for ceramic pieces made of clay. This lustrous coating enhances the natural beauty of clay, accentuates form and texture, and allows for decorative color effects. A shiny coating also makes the clay water-resistant. Numerous options exist for creating a glossy covering on dry clay.

This article explores the most popular coatings used to give clay a luminous, polished finish. Comparing the advantages and disadvantages of various shiny clay coverings provides helpful knowledge when selecting the ideal choice for your project.

Glazes

Glazes are vitreous coatings applied to ceramic wares to decorate, waterproof, or give a glossy finish. There are many types of glazes, but they generally fall into three main categories: raw glazes, fritted glazes, and underglaze.

Raw glazes are made from raw materials like silica, alumina, and fluxes. They fuse with the clay body during firing to form a glassy coating. These glazes are very glossy but tend to be less stable. Fritted glazes are made from prefused glass particles called frit. The frit helps stabilize the glaze chemistry. Underglazes are coatings containing pigments formulated to be applied under a transparent overglaze.

Glazes make clay shiny through the vitrification process. As the clay and glaze fire in the kiln, the glaze ingredients melt, flow, and fuse to the clay surface to create a smooth, glassy coating. The glaze fills in pores and creates a barrier, resulting in a glossy surface that reflects light evenly.

Glazes are typically applied by dipping or spraying bisqueware. Brushing can leave visible brush strokes. Proper thickness and evenness are important to avoid drips, crawls, or uneven coverage. Too thin and the clay body shows through, too thick can cause cracking or peeling.

Benefits of glazes include their decorative effects, durability, water resistance, and hygienic qualities. Drawbacks are the need to bisque fire before application, potential unstable chemistry, and toxicity of some ingredients requiring proper handling. Overall glazes are the most versatile and effective way to give clay a glossy shine.

Wax

Wax is a popular option for giving clay pieces a glossy shine. There are many types of wax that can be used on clay including beeswax, paraffin wax, carnauba wax, and microcrystalline wax. Each type has its own characteristics.

Beeswax is natural, has a lovely honey aroma, and gives a soft satin finish. Paraffin wax is highly refined and creates a bright gloss. Carnauba wax is very hard and produces a durable high-gloss shine. Microcrystalline waxes are blended to create versatile waxes great for clay crafts.

To apply wax to clay, rub a small amount directly onto the baked clay piece using a rag or brush. Multiple thin coats are better than one thick coat. Allow each coat to fully dry before adding the next. Too many layers can start to look chalky. The wax will soak into the clay and leave a smooth glossy finish.

Wax is easy to apply without any special tools. It enhances the natural look and feel of clay. Wax also provides protection from fingerprints and dust. However, wax finishes aren’t very durable. They can scratch or stain easily. Wax also lacks UV resistance so it can yellow over time.

Resin

Resin is another popular option for achieving a glossy shine on clay surfaces. There are several types of resin that work well for this purpose:

Epoxy Resin – A two-part resin that cures to a thick, durable, crystal clear finish. It provides the highest gloss but can yellow over time. Best for decorative objects.

UV Resin – Cures quickly with UV light. Lower in viscosity than epoxy so it can pick up more details. Glossy finish but not as durable over time. Good for jewelry and small decorative items.

Polyurethane Resin – Available as one-part and two-part formulas. Provides a flexible, glossy coat with good durability. Can be used on larger pieces.

To apply resin, make sure the clay is fully cured and sanded smooth. Mix the resin according to instructions, then pour or brush in layers, allowing to dry between applications. Using a blowtorch can help remove air bubbles. Too many layers may cause cracking or clouding. Resin provides a gorgeous high-gloss shine, but take care as fumes can be strong during application. It will also eventually yellow from UV light exposure if used outdoors or on light-colored clay.

Varnish

Varnish is a common coating used to give clay pots and sculptures a glossy, finished look. There are several types of varnish that work well for clay:

• Polyurethane – This is a very durable, plastic-based varnish that dries to a hard, protective coating. It provides a high-gloss finish.
• Resin – Resin varnishes contain natural resins suspended in a solvent. They provide a softer, warmer gloss compared to polyurethane.
• Acrylic – Acrylic varnishes are water-based and non-toxic. They provide a crystal clear finish.

To apply varnish to clay:

1. Make sure the clay is fully dry and cured. Clay must be fired before applying varnish.
2. Clean the surface thoroughly to remove any dust or debris.
3. Apply at least 2-3 thin, even coats of varnish using a soft brush or spray bottle, allowing each coat to fully dry in between.
4. Allow the final coat to cure for 24-48 hours before handling.

The advantages of varnish for clay:

• Enhances colors and provides a glossy appearance.
• Seals and protects the clay surface.
• Available in various finishes from satin to high-gloss.
• Durable and long-lasting.

Potential disadvantages:

• Can yellow or darken over time.
• Surface imperfections may show through glossy varnish.
• Fumes require proper ventilation during application and drying.

Oils

Oils like linseed oil and walnut oil are commonly used to give clay a beautiful sheen. There are a few types of oils that work well for sealing and protecting clay:

Linseed Oil – Made from flaxseeds, linseed oil penetrates deep into clay to provide water resistance. It has a long drying time but gives a lovely satin finish. Linseed oil is inexpensive and readily available.

Walnut Oil – Derived from walnuts, walnut oil leaves a smooth semi-glossy finish on clay. It dries faster than linseed oil. Walnut oil brings out rich colors in clay.

Tung Oil – Tung oil comes from the seeds of the tung tree. It dries to a hard, water resistant, glossy coating. Tung oil enhances the natural beauty of clay. It does have a strong odor during application.

Oils are applied using a soft cloth or brush with smooth strokes. Allow the clay piece to dry completely between coats. Most clays require 2-3 thin coats of oil for best results. Test oil on a tile or discarded piece first.

The advantage of oils is they soak into clay for a deep, natural-looking finish. Oils bring out the inherent richness of clay. They are non-toxic and easy to apply. The drawback is oils take longer to cure than other sealants. Proper drying time is needed between coats.

Polymers

A popular choice for coating and protecting clay sculptures and pottery is polymer coatings. Polymers form a plastic-like protective barrier over the clay surface. Some common types of polymers used are:

• Polyurethane
• Epoxy resin
• Acrylic

Applying a polymer coating involves brushing or spraying a thin layer evenly over the clay surface. Multiple coats are usually required to build up a protective barrier. Polymers penetrate into the clay providing a strong bond.

Pros of polymer coatings are:

• Durable and scratch resistant surface
• High gloss finish
• UV protection to prevent fading
• Waterproof protection

Cons are:

• Toxic fumes require proper ventilation
• Long curing times between coats
• Can develop bubbles if applied too thick

Overall, polymers provide a versatile protective coating for clay that can be customized for different finishes and effects.

Lacquer

Lacquer is another popular option for giving clay a shiny, glossy finish. There are several types of lacquer specifically formulated for use on clay and ceramics:

• Acrylic lacquer – Water-based and non-toxic, acrylic lacquer dries to a clear, durable gloss.
• Nitrocellulose lacquer – Made from cellulose nitrate and solvents, this lacquer produces an extremely durable high-gloss coating.
• Polyurethane lacquer – A two-part lacquer that cures to a thick, pliable coating that resists chipping and scratching.

Applying lacquer to clay involves several steps. First, the clay must be free of any dust or residue. Lacquer can be brushed or sprayed on in thin, even coats. Multiple coats are usually needed to achieve an optimal glossy finish. It’s important to allow ample drying time between coats. Once fully cured, the lacquer finish protects the clay and provides a beautiful glossy shine.

The pros of lacquer are that it dries to a very hard, durable gloss that resists scratches, chips, yellowing, and fading. Lacquer also brings out the natural colors and textures of clay very nicely. The cons are that some types contain solvents that require proper ventilation during application. Lacquer can also chip or crack if applied too thickly in too few coats.

Comparison of Clay Coating Options

When selecting a coating for clay, there are several factors to consider in order to choose the right option for your specific project and needs:

• Viscosity – Some coatings like lacquer and resin are thinner and provide a smooth, glass-like finish. Thicker coatings like wax allow for build up of layers and textures.
• Shine – Glazes, lacquer and resin provide the highest gloss. Oils and wax make a satiny or matte look.
• Durability – Glazes bond with the clay so it is highly durable. Wax and oils provide temporary protection that wears over time.
• Food safety – Unpigmented glazes, oils and waxes are often food safe. Other coatings may contain toxic elements.
• Application – Brushing is good for oils and waxes. Spraying works for thinner lacquers and resins. Glazes can be brushed, sprayed or dipped.
• Firing – Glazes and some resins require high firing temperatures. Others work at room temperature.

For decorative clay work, an oil or wax finish provides pleasing patina and sheen. For functional pottery and dinnerware, a durable food-safe glaze is recommended. Resins and lacquers create modern high-gloss finishes. Consider piece size, texture needs, safety, firing capabilities and desired look when selecting the optimal coating.

Conclusion

There are several ways to make clay shiny and add protective coatings. Glazes are a popular choice as they fuse to the clay body during firing to create a glasslike coating. Wax and resin can also be used to make clay shiny, though they offer less durability. Varnish and lacquer provide a durable clear coating while oils create interesting surface effects. Polymers offer versatility as they can be used before or after firing.

When choosing a coating, consider the level of shine, durability, and intended use of the clay piece. Test different options to find the right one for your project. Proper application and curing of coatings is also important for achieving the desired results. With the wide range of options available, you can find the perfect coating to make your clay creations shine.

Coatings serve important protective and aesthetic roles for clay pieces. By selecting the right coating and applying it properly, clay artists can enhance their works and allow them to withstand the test of time. With so many options to experiment with, the possibilities are endless when it comes to making clay shiny and beautiful.