Applying finish to wood typically involves preparing the surface, applying the finish, allowing it to dry, and often repeating the application process, especially when using multiple coats for durability and depth.
Preparing the Wood Surface
Before applying any finish, the wood surface must be clean, dry, and smooth. This usually involves sanding the wood progressively with finer grits of sandpaper to remove imperfections and create a smooth base.
Applying the First Coat
The method of applying the first coat depends on the type of finish being used (e.g., stain, varnish, polyurethane, oil). Common methods include:
- Brushing: Using a high-quality brush for even application.
- Wiping: Applying with a cloth, often used for oils or wiping varnishes.
- Spraying: Using a spray gun for a fine, even coat.
Apply the finish evenly, following the wood grain where applicable. Avoid applying too much at once, which can lead to drips or uneven drying.
Drying
Allow the first coat to dry according to the finish manufacturer's instructions. Drying times vary significantly based on the type of finish, humidity, temperature, and ventilation.
Applying Subsequent Coats (Intercoat Sanding)
For many finishes, applying multiple thin coats is better than one thick coat. Between coats, a crucial step is often required to smooth the surface and ensure good adhesion for the next layer.
According to the provided reference, after the first coat dries, you should lightly sand the surface.
- Use 320 grit sandpaper.
- Sand by hand instead of using a power sander.
- The purpose of this light hand sanding is to smooth out any dust nibs or imperfections and prepare the surface for the next coat without sanding off all the finish that was just applied.
Repeat the application and sanding process for subsequent coats as needed, following the finish manufacturer's recommendations for drying times and the number of coats.
Final Drying and Curing
Once the final coat is applied, allow the finish to dry completely and cure. Curing is the process where the finish hardens fully, which can take days or even weeks depending on the product. Avoid heavy use or placing objects on the finished surface until it is fully cured.
