The Art of Finishing: Oils, Stains, and Sealers Explained

Ask any experienced woodworker what separates a decent project from a great one, and they’ll probably say the same thing — the finish. You can spend hours cutting perfect joints and sanding every edge smooth, but the final coat is what brings your project to life. A good finish protects your work, enhances the grain, and adds that professional look that makes people stop and stare.

Finishing wood is part science, part art. There’s no single “best” way — it depends on what you’re building, what kind of look you want, and how much wear it’ll take. The goal is to understand how different finishes behave so you can choose the right one every time.

Why Finish at All?

Raw wood looks nice for a while, but it doesn’t stay that way. Dust, fingerprints, and moisture quickly take their toll. A proper finish seals the surface, prevents swelling and cracking, and brings out the natural color and depth of the grain. Some finishes soak into the wood for a natural feel; others sit on top like armor. The right one depends on the job.

Preparing the Surface

Before you think about finishes, surface prep is everything. Any scratch, glue spot, or uneven sanding mark will show through once you apply stain or oil. Start with 120-grit sandpaper, then move to 150, and finally 220 for most hardwoods. Always sand with the grain, not across it — cross-grain scratches are almost impossible to hide later.

After sanding, remove dust with a tack cloth or a clean, slightly damp rag. Don’t use compressed air unless it’s filtered; it can blow oil or moisture onto your wood. A spotless, smooth surface is the best canvas for a great finish.

Understanding the Main Types of Finishes

Finishes generally fall into three categories: penetrating finishes, surface finishes, and hybrids. Each has its own feel, durability, and look.

• Penetrating finishes (like oils) soak into the wood fibers, bringing out warmth and depth while leaving a natural, hand-rubbed appearance.
• Surface finishes (like varnish, polyurethane, and lacquer) form a protective film on top of the wood. They’re tougher and more resistant to water, heat, and wear.
• Hybrids (like oil-varnish blends) give you the best of both worlds — the natural look of oil with added protection.

Oils: Natural Beauty and Warmth

Oil finishes are favorites for people who want the wood to feel alive and organic. They soak in, highlight the grain, and give the surface a soft sheen instead of a shiny coat. The most common options are linseed oil, tung oil, and Danish oil.

• Linseed Oil: One of the oldest finishes around. Raw linseed takes forever to dry, so most people use boiled linseed oil, which has drying agents. It deepens color beautifully but can yellow over time.
• Tung Oil: Made from the nut of the tung tree, it dries faster and creates a slightly harder finish than linseed. Pure tung oil repels water well once fully cured, but it needs several coats for best results.
• Danish Oil: A blend of oil and varnish that penetrates easily and dries to a light satin sheen. It’s user-friendly and great for beginners who want the oil look with less waiting time.

To apply oil, flood the surface with a rag or brush, let it soak in for 15–30 minutes, then wipe off the excess. Repeat this two or three times, waiting a day between coats. The finish will deepen slightly with each layer. A final buff with a clean cloth leaves a silky touch that feels natural to the hand.

Stains: Adding Color Without Hiding the Grain

Stains change the wood’s color while letting the grain show through. They’re great when you want a uniform tone or need to match new wood to existing furniture. The most common stains are oil-based, but water-based and gel stains are popular alternatives.

• Oil-Based Stains: Easy to apply and slow-drying, giving you time to work. They penetrate deeply but can raise the grain slightly on softer woods.
• Water-Based Stains: Dry fast, clean up with water, and come in a wide range of colors. They’re great for indoor projects but can dry too quickly if applied in a warm, dry room.
• Gel Stains: Thick and easy to control — ideal for vertical surfaces or woods that blotch easily like pine or birch.

Always test your stain on a scrap piece from the same batch of wood before applying it to the final piece. Different species — even different boards — absorb stain differently. Once you’ve found the right color, apply evenly with a cloth or sponge, wait 5–15 minutes, then wipe off the excess with the grain.

Dealing With Blotching

Some woods, like pine, cherry, and birch, absorb stain unevenly, leaving dark patches or streaks. That’s called blotching, and it frustrates a lot of beginners. The fix is simple: use a pre-stain conditioner. It seals the surface just enough to control absorption, giving you an even color. Apply the conditioner, wait about 15 minutes, and stain while it’s still slightly damp.

Sealants and Topcoats: The Shield

Once the color and texture look right, you’ll want to protect it. Sealants and topcoats form a clear barrier that shields your work from scratches, water, and wear. The most common types are polyurethane, varnish, shellac, and lacquer.

• Polyurethane: Tough, durable, and water-resistant. Available in oil-based (warm tone) and water-based (clear, fast-drying) formulas. Ideal for tables, floors, and high-use surfaces.
• Varnish: Similar to polyurethane but slightly more flexible. Great for outdoor furniture because it expands and contracts with temperature changes.
• Shellac: A natural resin dissolved in alcohol. It dries fast, adds a warm amber tone, and works well for antiques or decorative pieces. Not great around heat or moisture.
• Lacquer: Dries quickly to a smooth, hard finish and is often sprayed. Common on cabinets and guitars. Best applied in thin coats in a well-ventilated space.

When applying any topcoat, thin, even layers beat thick ones every time. Three light coats sanded lightly between each (using 320-grit or finer) will look better and last longer than one heavy coat. Patience and thin layers are the real secrets of professional-looking finishes.

Mixing and Layering Finishes

Some finishes work beautifully together. For example, you can stain wood first, then apply a clear polyurethane or varnish on top for protection. Just make sure the base coat is fully dry before applying the next layer. Water-based topcoats can go over oil-based stains, but give the stain at least 48 hours to cure before sealing.

Never mix incompatible products — for instance, lacquer on top of polyurethane can peel or crack. When in doubt, test the combination on scrap wood first.

Common Mistakes to Avoid

• Skipping the sanding between coats — this step smooths the surface and ensures each layer bonds properly.
• Applying too much finish at once — it traps bubbles and dries unevenly.
• Ignoring dust — even a small speck can ruin a flawless surface.
• Rushing drying times — finishes may feel dry to the touch long before they’ve hardened underneath.

Give your finish time to cure fully before handling or assembling your project. Most finishes reach full hardness after a few days, even if they seem ready sooner.

Choosing the Right Finish for the Job

Here’s a quick guide to match finish type with project use:

• Cutting boards and utensils: Food-safe mineral oil or beeswax blend.
• Tabletops and furniture: Polyurethane or oil-varnish blend for durability.
• Outdoor projects: Marine varnish or spar urethane for UV and moisture protection.
• Decorative pieces: Shellac or Danish oil for warm, natural beauty.

Think about how the piece will be used — heavy wear needs tough finishes, while display pieces can focus more on looks.

Practice Makes Perfect

Finishing is one of those skills that only gets better with repetition. Keep scraps from each project and experiment. Try different stains, sealers, and oils side by side to see how they behave. Over time, you’ll develop a personal preference for certain looks and techniques.

If you like working with step-by-step instructions, Ted’s Woodworking includes finishing guides alongside many of its plans, showing how different oils and stains affect each species. It’s a great way to build confidence and consistency in your own work.

A good finish is like a handshake — it’s the final impression of your craftsmanship. Take your time, work clean, and enjoy the moment when that last coat dries and the grain glows back at you. That’s when woodworking stops feeling like a chore and starts feeling like art.