Do I Need To Prime Air Dry Clay Before Painting?

What is Air Dry Clay?

Air dry clay, also known as modeling clay, is a non-hardening clay that dries and hardens at room temperature. Unlike typical clays that require firing in a kiln, air dry clay will harden naturally just by leaving it exposed to the air.

There are two main types of air dry clay:

• Oil-based – Made from clay mixed with oils that help keep it workable and flexible as it dries.
• Polymer-based – Made from resin polymers like PVC or vinyl. Polymer clays dry very hard and become durable.

The main properties of air dry clay are:

• Does not require oven baking or firing to harden.
• Dries at room temperature by evaporation.
• Can be molded, shaped, and sculpted easily.
• Once dry, finishes with paints, varnishes, glazes.
• Relatively lightweight and easy to work with.

Does Air Dry Clay Need to Be Primed?

Whether or not you need to prime air dry clay before painting depends on the project and the desired finished look. Priming clay has some advantages as well as a few potential drawbacks to consider.

The main purpose of priming clay is to provide a uniform surface for painting. Unprimed clay is porous and can absorb paint unevenly, resulting in a blotchy or streaky appearance. Priming seals the surface so paint glides on smoothly and evenly. Primers also help paint adhere better to the clay.

On the other hand, some artists prefer the ability to control effects like subtle texture or varied absorption when painting directly on raw clay. Skipping the priming step also saves time and avoids potential issues like priming too heavily and obscuring fine details of the sculpture.

Most experts recommend priming air dry clay sculptures, especially if aiming for an evenly painted surface. Acrylic gesso is a common choice as it seals effectively and dries fast. Artists wanting to retain some natural clay texture can apply gesso lightly. Multiple thin coats are better than one thick coat.

In summary, priming clay before painting is advisable for most projects, but not strictly necessary. Consider the desired finish and effects when deciding whether to prime or not.

Primer Options for Air Dry Clay

There are a few common primer options to consider when prepping air dry clay for painting:

Acrylic Primer

Acrylic primer is a popular choice for priming air dry clay. Acrylic primer goes on smoothly, dries quickly, and provides a nice base for acrylic paint. Look for an acrylic primer formulated for clay, plaster, wood, or other porous materials.

Gesso

Gesso is another common primer for air dry clay. It’s traditionally used for priming canvas for painting. Gesso provides a bright white, matte surface. Make sure to sand the gesso once dry before painting on clay for better adhesion.

Specialty Primers for Clay

There are also some specialty primers made specifically for clay and ceramic bisque. These are formulated to bond well with clay and terracotta surfaces. Liquitex makes an acrylic primer tailored for clay that provides a nice smooth finish.

How to Apply Primer

When priming air dry clay, you have two main application options – using a brush or a spray primer. Each has its own pros and cons.

Brush-on primer:

• Allows you to easily control coverage and get into grooves and details
• Avoids primer wastage compared to spraying
• Can result in brush strokes in the finish if not applied properly

Spray primer:

• Goes on quickly and evenly
• Can coat hard-to-reach areas easily
• Risk of drips, uneven coverage if not used properly
• Requires proper ventilation

For both application methods, 2-3 thin coats are recommended to fully seal the clay and create an even base. Allow each coat to dry fully before adding the next. Drying times vary based on climate, primer type, and coat thickness – usually 1-2 hours between coats.

Prepping Clay Before Priming

Before applying primer to air dry clay, it’s important to properly prepare the surface. This will help the primer adhere better and lead to a smoother, more professional finish.

First, you’ll want to sand the clay gently with fine grit sandpaper. This will smooth out any fingerprints, bumps, or imperfections. Be careful not to sand too aggressively or you may remove details you want to keep. Wipe away any dust with a dry cloth after sanding.

Next, clean the surface with a damp cloth to remove any dirt, dust, or debris. Let the clay fully dry after cleaning before priming. Using a clean, dry paintbrush, you can also gently brush away any particles or dust.

Some clayers also recommend applying a thin sealant or varnish to the clay before priming. This helps protect the sculpture and provides an extra smooth base. Choose a water-based sealant and apply a thin, even coat per the manufacturer’s directions. Let this dry fully before priming.

Prepping your clay properly before starting the priming process will help you achieve better, longer lasting results.

Priming Techniques

When priming air dry clay, it’s important to use techniques that avoid leaving brush strokes and ensure full, even coverage across the entire surface. Here are some tips for effective priming:

If priming by hand with a brush, use light coats and keep the brush moving to avoid pooling paint and visible brush strokes. It’s better to apply several thin coats rather than one thick coat. Allow each coat to fully dry before adding the next.

Spray primers allow for a smoother, more consistent application. Hold the can 6-12 inches from the clay and apply light, even coats using a side-to-side sweeping motion. Rotate the sculpture as you spray to reach all angles and edges.

To ensure full coverage, visually inspect the clay from all sides after each coat of primer. Look for any spots that appear patchy or uneven. Target these areas when applying the next coat.

Priming outdoors on a non-windy day can help avoid drips and dust specks. But work in a well-ventilated area regardless of your priming method.

Proper priming prep and technique will provide a smooth base for acrylic, oil, or latex paints. This prevents the paint from absorbing unevenly into the clay sculpture.

Priming Clay Sculptures

When working with air dry clay sculptures, special care needs to be taken during the priming process. Unlike flat clay pieces, sculptures have complex shapes and hard-to-reach areas that require some finesse when applying primer.

For intricate sculptures with lots of crevices, use a soft brush to gently work primer into all the nooks and crannies. Stiff bristle brushes may skip over indented areas. Take your time and pay close attention to ensure primer fully covers every surface.

For larger clay sculptures, you may need to prime in sections rather than trying to coat the entire piece at once. Work on one surface area at a time, allowing primer to fully dry before moving onto the next section. This prevents uneven absorption and drying.

Position the sculpture so you can easily access the area you are priming. Sometimes clipping pieces onto rods or dowels helps with rotation. Get primer into every crook and underside for complete coverage.

When priming complex clay sculptures, patience and thoroughness are key. Avoid missing spots by carefully inspecting each area before moving onto the next. With some finesse, you can achieve smooth, professional results.

Painting on Primed Clay

Once the primer has fully dried on the sculpted clay piece, you can begin painting. When painting primed clay, you have the option to use acrylic or oil-based paints.

Acrylic paints are water-soluble, making them easy to thin out and clean up. They dry faster than oils and adhere well to surfaces like primed clay. Acrylics are a good choice if you want bright, opaque colors for painting clay.

Oil paints blend well and provide rich, translucent color. They take much longer to dry compared to acrylics. Oils allow more working time for blending and smoothing out brushstrokes. Oil paints give a luminous quality well-suited for subtle shading on clay sculptures.

Typically 2-3 thin coats of acrylic or oil paint are needed when painting over primer on clay. It’s important to let each coat fully dry before adding another layer. Rushing the paint drying time can cause cracking or lifting of the paint from the clay surface. Patience produces the best results.

Applying multiple thin layers creates a smooth, even coating. Thick coats are more likely to obscure detail and give an uneven painting finish. Lightly sanding between coats also helps achieve a flawless painted clay sculpture.

Troubleshooting Common Issues

When priming and painting air dry clay, you may run into some common issues that can affect the final look of your sculpture. Here are some of the most common problems and how to avoid them:

Bubbles in Primer

If you notice small bubbles forming in the primer, this is likely due to applying the primer too thickly. Thick coats of primer can trap air bubbles as they dry. To prevent bubbling, apply primer in thin, even coats allowing each coat to fully dry before adding another.

Paint Not Adhering

If paint is peeling or scratching off easily, the primer may not have adhered properly to the clay. Ensure the clay is fully cured, clean, and dry before priming. Rough up smooth areas with fine sandpaper so the primer has something to grip. Apply primer evenly in thin coats. Let the primer fully cure before painting.

Priming Too Thick

It’s easy to get carried away priming and apply too thick a coating. This wastes primer, extends drying time, and can obscure fine details. To avoid excess thickness, apply primer in multiple thin coats instead of one thick one. Check coverage after each coat dries before adding more.

Achieving a Professional Finish

To achieve a truly professional, sleek finish when painting air dry clay sculptures, there are some extra steps you can take beyond just applying paint:

Sanding Between Coats

Lightly sanding the clay surface with fine grit sandpaper (400+ grit) after each coat of primer or paint will help remove any bumps or uneven texture. This creates an ultra smooth finish for your next coat of paint. Be sure to wipe away any dust after sanding before painting again.

Applying a Clear Coat/Sealant

Using a clear acrylic sealant as a topcoat over your painted sculpture seals in the color and provides an attractive glossy finish. This also helps protect the paint from chipping or wearing over time. Apply 2-3 thin coats of sealant, allowing each coat to fully dry in between.

Polishing

As a final step, you can use a polishing compound and buffing wheel or rag to polish the dried clear coat on your sculpture. This removes any fine scratches and makes the finish incredibly glossy and smooth. Be sure to work in circular motions and not press too hard when polishing to avoid removing paint.