Preserving Red Cedar: Seal And Keep The Aroma

Red cedar is a highly versatile wood with a distinctive aroma that is valued for its durability, resistance to rot, and natural insect-repellent properties. Its unique qualities make it ideal for a range of applications, from exterior and interior building projects to furniture and accents. When it comes to sealing red cedar, the approach depends on whether the goal is to preserve its natural colour or maintain its aromatic qualities.

To preserve the colour of freshly milled red cedar, it is recommended to apply a finish as soon as possible, ideally before installation. Transparent or semi-transparent penetrating stains are suggested to protect the wood from moisture absorption, UV degradation, and the growth of mould and mildew. These stains can be applied using a brush, sprayer, pad, or roller, ensuring even coverage in grooves and vulnerable areas. Reapplication may be necessary every one to two years.

On the other hand, if the priority is to maintain the aromatic qualities of red cedar, leaving the wood unsealed is the best option. However, if sealing is required for protection or aesthetic purposes, several approaches can be considered. For interior woodwork, a thin coat of varnish or lacquer sanding sealer can be applied, followed by additional top coats. Penetrating oils, such as tung oil and linseed oil, are also effective for sealing the grain while preserving the wood's natural appearance. In both cases, it is essential to start with clean cedar and ensure proper ventilation during the sealing process.

For outdoor use, use a semi-transparent stain to maintain colour and prevent UV damage

When it comes to sealing red cedar for outdoor use, a semi-transparent stain is a great option to maintain the colour and prevent UV damage. Here's a detailed guide on choosing and applying the right semi-transparent stain for your project:

Choosing the Right Stain

Select a high-quality semi-transparent stain designed for exterior use on cedar. Look for products that offer UV protection and include fungicides to inhibit mould and mildew growth. The more pigment in the stain, the better it will protect against UV rays. While water-based stains are more environmentally friendly, oil-based stains tend to penetrate the wood more effectively and provide longer-lasting protection.

Surface Preparation

Ensure the cedar surface is clean, dry, and free from dirt, oil, and other contaminants. If the cedar has been previously painted or stained, you may need to remove the old finish by sanding, brushing, washing, or using chemical strippers. For smooth-planed, flat-grained cedar, consider scuff-sanding with 50-60 grit sandpaper to improve the stain's adhesion.

Application Techniques

Semi-transparent stains can be applied by brush, sprayer, pad, or roller. Brushing typically provides the best penetration and performance. If using a sprayer, be sure to back-brush to avoid blotchy patterns as the stain weathers. Always follow the manufacturer's instructions for the best results.

Application Process

Start by applying the stain to a small area or two to three boards at a time to avoid lap marks. Stir the stain regularly during application to prevent the colour pigments from settling. Use caution when staining "green" or unseasoned wood, as over-application can lead to a sticky surface film. Allow the stain to penetrate the wood, and always ensure the wood can accept the stain before applying a second coat.

Maintenance

The service life of semi-transparent stains will depend on various factors, including the amount of pigment, UV protectants, sunlight intensity, and the surface texture. Regular maintenance and reapplication will be necessary to maintain the desired appearance and protection. Follow the manufacturer's recommendations for the specific product you choose.

For indoor use, seal with penetrating oils to maintain a raw, natural look

To seal red cedar for indoor use while maintaining its raw, natural look, it is recommended to use penetrating stains or oils. Here are some detailed steps and instructions to guide you through the process:

Choosing the Right Product

Select a high-quality penetrating stain or oil designed for indoor use on cedar. Look for products that are specifically formulated to enhance the natural colour and grain of the wood while providing protection. Some recommended options include transparent or semi-transparent penetrating stains and Danish oil.

Surface Preparation

Before applying any finish, ensure that the cedar surface is clean, dry, and free from contaminants such as dirt, oil, or other foreign substances. If necessary, use a mild detergent solution to clean the wood and allow it to dry completely before proceeding.

Application Technique

Follow the manufacturer's instructions for the specific product you have chosen. In general, penetrating stains or oils can be applied using a brush, sprayer, pad, or roller. Always back brush to ensure even coverage and avoid allowing the product to pool on any surface. Stir the stain or oil regularly during application to prevent pigment settling and ensure consistent colour.

Timing and Coats

Apply the finish before installing the cedar if possible. For best results, stain or oil all four sides of each piece of cedar before installation. For "green" or unseasoned wood, or wood that will be installed horizontally (such as decking), wait a few months before applying a second coat. The wood will absorb more finish the drier it is, so be cautious when applying to "green" wood to avoid over-application, which can lead to a sticky surface that attracts dirt.

Maintaining the Finish

To maintain the natural look and aroma of the cedar, regular cleaning and maintenance are essential. Keep the cedar away from moisture, sunlight, and termites by sealing openings and avoiding placement in moist areas. Follow the manufacturer's recommendations for re-application of the finish to ensure long-lasting protection and beauty.

Avoid film-forming finishes like lacquer, shellac, urethane and varnish

When it comes to sealing and finishing red cedar, it is important to avoid certain types of finishes, particularly film-forming finishes like lacquer, shellac, urethane, and varnish. These finishes can negatively impact the wood and its appearance over time.

Lacquer, for instance, is derived from the resin of varnish trees and can be applied with a brush or spray. While it forms a tough and durable finish, it is susceptible to ultraviolet light, which can cause the finish to become brittle, develop cracks, and eventually fail. Similarly, shellac, a natural finish made from the "cocoon" of the lac beetle, is also susceptible to ultraviolet radiation. Over time, shellac can darken with age, and it is not as durable as other finishes.

Urethane, a type of varnish, can also be detrimental to red cedar. Varnishes tend to add a darker tone to the wood and can make it more prone to scratches. They require multiple coats and careful application techniques, and even then, the finish may show scratches and become brittle over time.

Overall, these film-forming finishes can detract from the natural beauty of red cedar and fail to provide adequate protection. Instead, it is recommended to use natural finishes such as penetrating stains or oils, which enhance the wood's colour and provide better protection against the elements.

For painting, prime with a high-solid primer to prevent bleed-through

To seal red cedar and maintain its aroma, you can use a wood sealer. This will help preserve the beauty of the wood and prevent moisture absorption, which can lead to mould and mildew.

If you want to paint red cedar, it is important to use a primer to prevent bleed-through of tannins, which can cause staining. Here are some tips for using a high-solid primer to prevent bleed-through when painting red cedar:

• Choose a high-quality, high-solid stain-blocking primer that is specifically designed for exterior wood and to block stains. Look for an exterior oil-based primer or a water-based primer with high solid content.
• Prepare the wood surface by cleaning it with a mixture of denatured alcohol and water, or a degreaser/detergent if it is very grimy. Make sure to remove any dirt, grease, hair and other contaminants.
• Lightly sand the wood with a fine-grit sandpaper (150-320 grit) to create a smooth surface and remove any imperfections. Wipe away the dust with a tack cloth or a damp cloth.
• Apply the primer according to the manufacturer's instructions. Use a brush, roller or sprayer to apply a thin, even coat of primer to the wood. Make sure to cover all surfaces, including the edges and ends of the wood.
• Allow the primer to dry completely according to the manufacturer's instructions. This may take several hours or even overnight.
• Lightly sand the primed surface again with a fine-grit sandpaper to create a smooth base for the paint. Remove the dust with a tack cloth.
• Apply a second coat of primer if needed, especially if you can still see tannins or stains coming through.
• Choose a suitable paint for exterior wood, such as an acrylic/latex paint. Follow the manufacturer's instructions for application and allow it to dry completely.
• If desired, apply a topcoat or sealer to protect the paint and enhance its durability.

By following these steps, you can effectively use a high-solid primer to prevent bleed-through when painting red cedar while also maintaining its aroma with a suitable sealing product.

To maintain aroma, leave unsealed or use cedar oil

To maintain the aroma of red cedar, you can leave it unsealed or opt for a finish using cedar oil. Here are some detailed steps and considerations for each approach:

Leaving Red Cedar Unsealed

Red cedar, when left untreated, will naturally weather and develop a silvery-grey patina, especially in coastal areas, creating a "beachy" look that is often desired. Due to its unique properties, red cedar can perform satisfactorily for many years without any sealing or finishing. However, if you wish to maintain the natural colour of freshly milled red cedar, it is recommended to apply a finish as soon as possible, ideally before installation, to protect it from moisture absorption, UV degradation, dirt, and mould.

Using Cedar Oil on Red Cedar

Cedar oil can be used to rejuvenate and restore the natural aroma of red cedar while also providing a protective finish. Here are some steps and tips for using cedar oil:

• Prepare the Surface: Ensure there is no existing finish on the red cedar surface. Clean the surface thoroughly with a tack cloth to remove dust, debris, grease, and dirt. You can also use a mild detergent solution to remove any stubborn dirt or contaminants.
• Sand the Surface: After cleaning, sand the entire surface with fine-grit sandpaper (120-220 grit) to create a smooth finish and open the wood grain. If you want to raise the wood grain for a better finish, wet the surface before sanding.
• Apply Cedar Oil: Pour cedar oil into a container and apply it generously and evenly across the entire surface using a brush, sponge, or lint-free rag. Always follow the direction of the wood grain to achieve a uniform finish.
• Allow Drying and Curing: Cedar oil takes time to dry and cure. Leave the oil to dry for about 6 hours between coats, and allow at least two weeks for the final cure. The curing process will result in a hard, protective finish.
• Apply Additional Coats: Depending on the desired level of protection, you may need to apply multiple coats of cedar oil. Two to three coats are usually sufficient for adequate protection.
• Maintenance: To maintain the finish, regularly clean the red cedar surface with a mild soap solution. Reapply cedar oil as needed, typically once every 1-2 years, to refresh the aroma and protection.

By following these steps and considerations, you can effectively maintain the aroma of red cedar while also providing a degree of protection to the wood.

Frequently asked questions