The Complete Guide to Wood Finishes: Choosing the Right Protection for Every Project

Every woodworker eventually faces the same question: what finish should I use? The answer depends on the project, your skill level, the wood species, and how the piece will be used. This comprehensive guide covers every major finish type, helping you make informed decisions for any project.

Understanding How Finishes Work

All wood finishes serve two purposes: protection and appearance. They shield wood from moisture, dirt, UV damage, and physical wear while enhancing (or altering) the wood’s natural color and figure.

Finishes fall into two broad categories based on how they achieve this protection:

Penetrating Finishes

These finishes soak into wood fibers, hardening within the wood itself. They don’t form a distinct surface film – instead, they become part of the wood structure. Pure oils and oil-wax blends fall into this category.

Advantages: Easy application, natural look and feel, simple repairs (just apply more), no peeling or flaking possible.

Disadvantages: Less water resistance, require more frequent maintenance, limited protection against physical wear.

Film-Forming Finishes

These finishes cure into a hard layer on top of the wood surface. Polyurethane, lacquer, shellac, and varnish all form films of varying hardness and thickness.

Advantages: Superior moisture protection, excellent wear resistance, longer intervals between maintenance.

Disadvantages: Can peel or chip if damaged, more skill required for application, repairs often require complete refinishing.

Penetrating Oil Finishes

Tung Oil

Extracted from the nut of the tung tree, pure tung oil has been used for centuries. It penetrates deeply, hardens within the wood, and provides excellent moisture resistance for a penetrating finish.

Application: Apply liberally, let soak 15-30 minutes, wipe off all excess. Repeat daily for a week or until the wood stops absorbing oil. Each coat adds depth and protection.

Cure time: Long. Each coat needs 24-48 hours before recoating. Full cure takes 30+ days.

Appearance: Slightly darkens wood and adds a warm amber tone. Produces a low-luster matte finish that many describe as “natural.”

Durability: Moderate. Better water resistance than most penetrating finishes but still requires annual maintenance for heavily used surfaces.

Best for: Projects where you want wood to look and feel like wood, not like plastic. Handles, tool bodies, turnings, sculptural pieces.

Watch out for: “Tung oil finish” products are often mostly varnish with little actual tung oil. Read labels carefully if you want pure tung oil.

Linseed Oil

The traditional woodworker’s oil, pressed from flax seeds. Available as raw linseed oil (extremely slow drying) or boiled linseed oil (treated with metallic driers for faster cure).

Application: Similar to tung oil. Apply, wait, wipe excess. Multiple coats build protection.

Cure time: Raw linseed can take weeks per coat. Boiled linseed oil dries overnight but takes weeks to fully cure.

Appearance: Yellows over time, which works well on some woods (walnut, oak) but may be unwanted on lighter species.

Durability: Modest. Provides basic protection but needs regular renewal.

Best for: Historic restorations, outdoor furniture (when refreshed regularly), projects where a traditional look matters.

Watch out for: Rags soaked in linseed oil can spontaneously combust. Always spread them flat to dry or submerge in water before disposal.

Danish Oil

Despite the name, Danish oil isn’t a specific product – it’s a category of oil-varnish blends. Different manufacturers use different formulas, but typically the mix includes tung or linseed oil, varnish, and mineral spirits.

Application: Flood the surface, let soak, wipe excess. Easier than pure oils because the varnish content speeds drying.

Cure time: Much faster than pure oils. Usually recoat-ready overnight.

Appearance: Slightly more sheen than pure oils due to varnish content. Builds a thin protective layer with multiple coats.

Durability: Better than pure oils, less than full film finishes. A good middle ground.

Best for: Everyday furniture, when you want oil ease with somewhat better protection.

Film-Forming Finishes

Shellac

One of the oldest finishes still in use, shellac is made from lac bug secretions dissolved in alcohol. It sounds strange, but shellac produces beautiful, touchable finishes that have protected fine furniture for centuries.

Application: Brush or pad on in thin coats. French polishing – the traditional application method – involves padding on many micro-thin layers.

Cure time: Very fast. Dry to touch in minutes, recoat-ready in 30-60 minutes. Fully cured within hours.

Appearance: Warm, glowing finish. Orange shellac adds amber warmth; blonde or super-blonde shellac stays clearer. High-gloss to satin depending on application and rubbing.

Durability: Moderate. Not water-resistant (water spots form, though they can be removed). Not alcohol-resistant. Excellent for pieces that won’t see heavy use or liquid exposure.

Best for: Fine furniture, antique restoration, as a sealer under other finishes, quick projects needing fast turnaround.

Watch out for: Shellac has a shelf life. Old shellac won’t dry properly. Buy fresh or buy flakes and mix your own.

Lacquer

The production finish of choice for most furniture manufacturers. Lacquer dries by solvent evaporation, making it fast and foolproof. Each new coat partially dissolves into the previous coat, creating excellent adhesion.

Application: Almost always sprayed. Brushing lacquer exists but is less common. Requires proper spray equipment and good ventilation.

Cure time: Extremely fast. Dust-free in minutes, recoatable in 30 minutes, handling-ready in hours.

Appearance: Clear, water-white finish that won’t yellow like oil-based products. Available in any sheen from dead flat to mirror gloss.

Durability: Good scratch resistance, moderate water resistance. Can be repaired by spraying more lacquer (new coat melts into old).

Best for: Production work, when speed matters, light-colored woods where yellowing would be a problem.

Watch out for: Fumes are significant – requires proper ventilation and respiratory protection. Not suitable for outdoor use.

Polyurethane

Modern polyurethane finishes offer the best protection available in a brushable format. They’re available in oil-based and water-based formulations with different characteristics.

Oil-Based Polyurethane:

The classic hardware store finish. Durable, forgiving, and readily available.

Application: Brush or wipe (wipe-on poly is oil poly thinned for rag application). Moderate skill required to avoid runs and brush marks.

Cure time: Slow. 24+ hours between coats, 30 days for full cure.

Appearance: Amber color that deepens over time. Adds warmth but can look orange on some woods. High-gloss versions have that classic “furniture store” sheen.

Durability: Excellent. Best water and wear resistance of common consumer finishes. Kitchen tables, countertops, high-traffic surfaces.

Watch out for: Yellowing over time is inevitable. On very light woods (maple, ash) this may become objectionable.

Water-Based Polyurethane:

Modern water-based polys have largely caught up to oil-based in durability while offering faster dry times and clearer color.

Application: Brush, pad, or spray. Dries faster, so technique matters – work quickly and don’t over-brush.

Cure time: Much faster than oil. Recoat in 2-4 hours, handling-ready overnight.

Appearance: Crystal clear, no amber shift. Stays that way over time.

Durability: Excellent. Modern formulations match or exceed oil poly performance.

Best for: Light-colored woods, when you need fast turnaround, low-VOC requirements.

Varnish

Traditional varnish (oil-based, long-oil formulations) remains the gold standard for outdoor protection. Marine varnishes are the most durable, designed for boats that live in water.

Application: Brush on in thin coats. Varnish levels well but takes forever to dry – dust is the enemy.

Cure time: Very slow. 24-48 hours between coats. Full cure can take weeks.

Appearance: Warm amber tone, builds to a deep, lustrous finish with multiple coats.

Durability: Excellent UV resistance, flexibility for outdoor temperature swings, outstanding water protection.

Best for: Outdoor furniture, exterior doors, boats, anywhere that sees sun and weather.

Specialty Finishes

Wax

Wax alone provides minimal protection but adds a beautiful tactile quality. Often used over other finishes as a final layer.

Application: Rub on with cloth or #0000 steel wool, let haze, buff to sheen.

Durability: Very low. Wax needs refreshing every few months on used surfaces.

Best for: Final layer over harder finishes, pieces that will see minimal use, achieving a hand-rubbed look.

Conversion Varnish

A two-part catalyzed finish used in professional shops. Extremely durable but requires specific equipment and expertise.

Best for: Professional production, commercial furniture, high-wear commercial applications.

Epoxy

Two-part epoxy creates a thick, glass-like coating. Popular for bar tops and tables with embedded objects.

Application: Mix parts precisely, pour and spread, let self-level. Torch to remove bubbles.

Durability: Excellent moisture and wear resistance. Some yellowing with UV exposure.

Best for: Bar tops, river tables, encasing objects, thick build waterproof surfaces.

Choosing the Right Finish

Consider the Use

Kitchen tables and counters: Water-based or oil-based polyurethane for durability. Water-based if you want to preserve light wood color.

Fine furniture: Shellac for warmth and traditional appearance. Lacquer for production. Oil poly for maximum durability.

Outdoor furniture: Marine varnish or exterior-rated products. Penetrating oils work but need frequent renewal.

Food contact surfaces (cutting boards, salad bowls): Pure mineral oil or walnut oil for frequent use items. Properly cured tung oil is also food-safe.

Consider the Wood

Light woods (maple, ash, birch): Water-based finishes preserve color. Oil-based products add amber that may or may not be desired.

Dark woods (walnut, mahogany): Oil-based finishes enhance depth and warmth. The amber shift is usually welcomed.

Open-pored woods (oak, ash): May need pore filler for a glass-smooth film finish. Penetrating finishes follow the texture.

Consider Your Skills

Beginner-friendly: Danish oil, wipe-on poly, pre-catalyzed finishes. Hard to mess up.

Intermediate: Brushed polyurethane, shellac. Technique matters but mistakes can be corrected.

Advanced: Sprayed lacquer, traditional varnish, French polish. Requires equipment, skill, and practice.

Preparation for Any Finish

No matter which finish you choose, preparation determines results:

1. Sand progressively through grits (100, 150, 180, 220 for most finishes)
2. Remove dust completely – vacuum, then tack cloth
3. Raise the grain with water before water-based finishes
4. Apply conditioner on blotch-prone woods before staining
5. Test on scrap of the same wood species

The finish can only be as good as what’s underneath it. Rushing preparation shows in the final result every time.

Final Thoughts

There’s no single “best” finish – only the right finish for each specific project. A museum-quality jewelry box needs different protection than a kitchen cutting board. An heirloom dining table calls for different considerations than a shop workbench.

Start by identifying what the piece needs to resist: water, wear, UV, heat, chemicals. Then narrow options by your skill level and equipment. Finally, choose based on the look you want to achieve. With this systematic approach, finish selection becomes straightforward rather than overwhelming.