Wood Door Finishing and Care Instructions

doors

Wood is a naturally dynamic material – it breathes, responds, and adapts to its surroundings. All wood products exchange moisture with their environment. Though a quality finish can slow this process, coated wood will still react to environmental changes.

In high humidity, wood absorbs moisture and expands. In low humidity, it releases moisture and contracts. This movement is a natural characteristic of real wood, not a defect.

To ensure long-term performance, Sun Mountain uses properly kiln-dried wood, maintaining an optimal moisture content of 8% to 10%, which is ideal for climate-controlled homes. For the best results, interior humidity should be maintained between 40% to 50%. Without proper climate control, dimensional changes may occur, which can affect performance. Special care should be taken during storage and installation to maintain optimal conditions.

Other points to consider:

Wood is a natural material, and extreme moisture or dryness can cause movement over time, such as panel expansion or contraction, joint separation, veneer checking or cracking, delamination, or bowing. In severe cases, the door’s structural integrity may be affected.
For exterior applications with high exposure to direct sunlight or moisture, Sun Mountain recommends a non-wood alternative to ensure durability and longevity.
In seasonal climates, doors may expand and bind during humid months, then contract and create visible gaps in the drier seasons. This is normal for solid wood construction.
If trimming is necessary, all exposed edges must be sealed and refinished immediately to prevent moisture absorption and damage.
Painted wood doors will naturally reveal “seams” at the joints as the wood responds to environmental changes.
Unfinished doors must be fully finished and sealed on all six sides within 14 days of delivery. A quality finish slows moisture absorption, but it does not eliminate it. Maintaining consistent humidity is essential during storage, installation, and use is key to maintaining a door’s performance and longevity.

factory pre-finished doors

Sun Mountain firmly believes that the final quality of a door’s finish is directly, and perhaps most critically, determined by the quality of sanding before the first coating is applied. Poor finishes are almost always the result of inadequate hand sanding, poor finishing materials, and or/an improper finishing environment.

Our factory finishing process is meticulous and produces a flawless, durable result:

Precision Sanding: After machine sanding, each door is hand-sanded with 150-180 grit rotary orbital sanders for approximately 15 to 20 minutes per side.
Detail Work: Sticking and panel profiles are carefully finger-sanded, with special attention to exposed end grain. Minor dents are expertly repaired using water, a hot iron, and light sanding.
Stain Application: Stain is applied using an HVLP spray gun in a climate-controlled booth with an air make-up system. It is then allowed to penetrate the wood and air-dry naturally.
Sealing for Protection: A catalyzed vinyl sealer is sprayed on all six sides of the door and air-dried to enhance durability, moisture, and resistance.
Final Fine Sanding: Once dry, the entire door is hand-sanded again (150-180 grit) to create an ultra-smooth surface to the topcoat.
Glazing (as applicable): Glazes are brushed on and selectively wiped off, using an artist’s eye to enhance highlights and shadows.
Durable Topcoat: A cabinet-grade, catalyzed-conversion varnish topcoat is applied to form a protective finish that resists scratches, nicks, dents, and moisture.

This meticulous process creates a long-lasting finish that enhances the natural beauty of the wood while also withstanding everyday wear and tear.

Finish/glaze instructions

A high-quality wood finish depends on several key factors: proper sanding, the right environment (including temperature, humidity, and dust control), high-quality materials, and precise technique. For optimal results, follow these steps carefully:

Sanding: Begin with 150-180 grit sandpaper. Use an orbital sander for efficiency and hand-sand details and edges for a smooth, even surface.
Create the Right Environment: Work in a clean, dust-free space with minimal airflow. The ideal temperature range is between 60°F and 80°F. Controlled conditions are essential for a flawless finish.
Apply Stain: Use an HVLP spray gun (or comparable equipment). Sun Mountain’s stain features dye pigments in a low-VOC, low-HAPS acetone solvent base for rich, uniform color.
Seal Coat Application: Apply Sun Mountain’s cabinet-grade vinyl sealer and catalyzed-conversion varnish system. High-quality lacquer, varnish, or comparable finishes will also work for this step.
Lightly Sanding: Once the seal coat dries, lightly sand with (150-180) grit sandpaper to create a smooth, even texture.
Glazing (as applicable): Apply glaze by brush or spray, then wipe off, allowing it to settle in corners and details to add depth and highlight the natural beauty of the wood.
Finish Coat: Apply a high-quality catalyzed-conversion varnish or lacquer for durable protection and an elegant final appearance.
Drying: Allow each coat to dry completely in a dust-free area to ensure lasting quality.

DISCLAIMER: Sun Mountain provides an exceptional factory-applied finish, but cannot guarantee the results for finishes applied by others.

Finishing Maintenance

Proper maintenance helps preserve the beauty and longevity of wood finishes. Follow these guidelines for both interior and exterior doors:

Interior Doors and Trim

Dust and Cleaning: Dust regularly to maintain the door’s appearance. Occasionally, wipe with a damp (not wet) cloth to remove dirt and smudges.
Cleaning Products: Mild detergents like Murphy’s Oil Soap are acceptable. Avoid furniture polishes and waxes, which can cause buildup and cloud the finish.
Avoid Harsh Cleaners: Never use vinegar, citrus-based cleaners, paint removers, window cleaners, brick or siding washes, or abrasive cleaners, as they can damage the finish.

Exterior Doors

Exposure Effects: Finished deterioration is directly related to exposure to sunlight, rain, and snow. Most exterior finishes will degrade over time.
Regular Maintenance: Inspect and clean exterior doors every six months (spring and fall) using a damp cloth to remove surface buildup.
Refinishing: Depending on exposure and climate, exterior doors may require refinishing as often as once a year. Use a high-quality exterior lacquer or varnish system and follow the manufacturer’s instructions for the best results.