WOOD FINISHING TECHNIQUES

The Art of Wood Finishing

A beautiful finish transforms raw wood into a finished piece that showcases the grain, protects the surface, and stands the test of time. Whether you prefer the natural look of oil finishes or the durability of polyurethane, proper finishing technique makes the difference between amateur and professional results.

Surface Preparation

Perfect finishing starts with perfect preparation. No finish can hide poor sanding or surface defects. The goal is a surface that's uniformly smooth with no scratches visible to the eye.

Sanding Progression

Start with the coarsest grit needed to remove mill marks and flatten the surface, typically 80 or 100 grit. Progress through 120, 150, 180, and finish with 220 grit. Never skip grits—each grit removes the scratches from the previous grit. Skipping grits leaves deep scratches that will show through the finish.

Raising the Grain

After final sanding, wipe the wood with a damp cloth to raise the grain. Let it dry completely, then lightly sand with 220 grit. This prevents the grain from raising when you apply water-based finishes or stain.

Removing Dust

Dust is the enemy of a smooth finish. After sanding, vacuum thoroughly, then wipe with a tack cloth or microfiber cloth slightly dampened with mineral spirits. Let any moisture evaporate before applying finish.

Staining

Stain adds color while allowing the wood grain to show through. However, staining can be tricky—some woods accept stain evenly while others become blotchy.

Pre-Stain Conditioner

Softwoods like pine and cherry tend to absorb stain unevenly, creating dark blotches. Pre-stain conditioner partially seals the wood so stain penetrates more uniformly. Apply conditioner, wait 15 minutes, then apply stain while the conditioner is still wet.

Application Technique

Apply stain liberally with a brush or cloth, working it into the wood. Let it penetrate for 5-15 minutes depending on desired color intensity. Wipe off excess stain with clean rags, wiping with the grain. The longer you wait before wiping, the darker the color.

Gel Stain

Gel stains sit on the surface rather than penetrating deeply, making them excellent for blotch-prone woods and for achieving uniform color. They're also ideal for vertical surfaces where liquid stain would run.

Oil Finishes

Oil finishes penetrate the wood rather than building a surface film. They're easy to apply, enhance natural wood beauty, and are simple to repair. However, they provide less protection than film finishes.

Boiled Linseed Oil

Traditional and inexpensive, boiled linseed oil (BLO) provides a warm, amber tone. Apply liberally, let soak for 20-30 minutes, then wipe off all excess. Drying time is slow—wait 24 hours between coats. Apply 3-5 coats for best protection.

Tung Oil

Pure tung oil is more water-resistant than linseed oil and doesn't amber as much. It takes longer to cure but provides better protection. Many "tung oil" products are actually tung oil varnish blends that dry faster.

Danish Oil

Danish oil is actually a blend of oil and varnish. It penetrates like oil but builds slight surface protection like varnish. It's easy to apply and provides a good balance of beauty and protection. Excellent for furniture and cutting boards.

Varnish and Polyurethane

Film finishes create a protective layer on the wood surface. They provide excellent protection from water, alcohol, and wear, making them ideal for tables, bars, and high-use furniture.

Oil-Based Polyurethane

The most durable finish for furniture. Oil-based poly ambers slightly, enhancing warm wood tones. It's available in gloss, semi-gloss, and satin sheens. Apply with a quality brush, thinning the first coat 10% for better penetration. Sand lightly between coats with 320 grit. Three coats minimum for table tops.

Water-Based Polyurethane

Dries clear without ambering, making it ideal for light woods like maple. It dries faster than oil-based, allowing multiple coats in one day. However, it raises the grain more and isn't quite as durable as oil-based. Use synthetic brushes or foam applicators.

Wipe-On Polyurethane

Thinned polyurethane applied with a cloth. It's foolproof—no brush marks, runs, or bubbles. The thin coats build slowly, requiring 5-7 coats for full protection, but the results are beautiful. Excellent for beginners and small projects.

Lacquer

Lacquer is the finish of choice for professional furniture makers. It dries extremely fast, builds quickly, and can be rubbed out to a glass-smooth finish. However, it requires spray equipment and good ventilation.

Spray Lacquer

Nitrocellulose lacquer is sprayed in thin coats that dry in minutes. Multiple coats can be applied in a day. The finish is repairable—new lacquer melts into old coats. Requires HVLP spray gun or aerosol cans for small projects.

Pre-Catalyzed Lacquer

More durable than nitrocellulose lacquer, pre-cat lacquer is excellent for cabinets and furniture. It's more resistant to water and chemicals. Once cured, it cannot be repaired by recoating like nitrocellulose.

Shellac

Shellac is a natural finish made from lac beetle secretions. It's been used for centuries and provides a beautiful, warm finish. Shellac is alcohol-soluble, making it easy to repair but vulnerable to alcohol spills.

Application Best Practices

Choosing the Right Finish