Finish Strong: Polyurethane and Hard Wax Oil

Written By Peter Jonnes

As a woodworker, I spend countless hours selecting the right wood, milling lumber, jointing boards, and sanding surfaces to perfection. But the journey isn’t over until the finish is applied. The finish is the final product the customer sees; it’s the part you touch, the part you see, and the shield that protects the piece for decades to come.

In my shop, I rely on two specific high-performance finishes: Polyurethane and Hard Wax Oil.

I am often asked, "Which one is better?" The honest answer is that neither is "better"—they are just different tools for different lifestyles. Both are premium options that I stand behind, but they interact with the wood—and your daily life—in distinct ways.

This guide breaks down the differences to help you decide which finish belongs in your home.

1. The Mechanics: How They Protect the Wood

To understand the difference, you have to look at where the finish sits in relation to the wood fibers.

Polyurethane: The Shield

Think of Polyurethane as a transparent suit of armor. When applied, it sits on top of the wood surface. As it cures, the resins cross-link to form a hard, solid plastic-like film. This film creates a barrier between the environment and the wood. Nothing touches the wood unless it breaks through that film first.

Hard Wax Oil: The Bond

Hard Wax Oil (HWO) takes a different approach. It is a "penetrating" finish. The oil soaks deep into the wood fibers, saturating them and hardening from within to strengthen the timber.1 Meanwhile, the wax component remains on the surface to provide a thin, microporous (breathable) layer of resistance. It works with the wood rather than covering it up.

2. The Look and Feel

This is usually the deciding factor for my clients who value aesthetics and tactile experience.

Polyurethane

  • The Look: Polyurethane generally alters the appearance of the wood slightly more, often adding a permanent "wet look."2 It is available in various sheens, but it naturally leans toward a higher gloss or semi-gloss reflection. It creates a distinct separation between your eye and the grain.

  • The Feel: Because the finish sits on top, when you touch a poly-finished table, you are touching the finish, not the wood. It feels smooth, slick, and uniform—similar to a high-end glass or plastic surface.

Hard Wax Oil

  • The Look: HWO is prized for its natural beauty. It highlights the grain and figure of the wood without looking "coated." It typically has a matte or satin sheen that absorbs light rather than reflecting it, giving the piece a warm, organic presence.

  • The Feel: This is where HWO shines. It preserves the natural texture of the timber. When you run your hand across the table, it feels like smooth, velvety wood. It feels warm to the touch, unlike the cooler feel of polyurethane.

3. Durability and "Life-Proofing"

Both finishes are durable, but they handle stress differently.

Polyurethane: The High-Traffic Hero

Polyurethane is the king of abrasion resistance. If you slide a ceramic plate across the table, poly is less likely to show a mark. It creates a sealed surface that is virtually impervious to liquids. You can leave a spill on a poly table for hours, and it likely won't penetrate the film.

  • Best feature: Ultimate resistance to scratches and water.

Hard Wax Oil: The Flexible Defender

HWO is incredibly tough, but in a different way. It is water-repellent (liquids will bead up), but because it is microporous, standing water left for a long time can eventually leave a mark. However, its greatest strength is elasticity. As wood expands and contracts with seasonal humidity changes, HWO moves with it. Polyurethane, being a rigid shell, can sometimes crack if the wood moves significantly (though this is rare in quality furniture).

  • Best feature: It never peels, flakes, or cracks.

4. Maintenance and Repairability

This is the most critical trade-off to consider for the long term.

The Polyurethane Trade-Off

  • Maintenance: Very low. You can clean it with almost any mild household cleaner. You don't need to do anything to it for years.

  • Repairability: Low. If you scratch polyurethane, you have scratched the "armor." You cannot simply spot-repair that one area because the new finish won't blend invisibly with the old cured film.

  • The Reality: To fix a deep scratch or a worn area on a poly table, you typically have to sand the entire tabletop down to bare wood and refinish the whole thing.

The Hard Wax Oil Trade-Off

  • Maintenance: Moderate. You should use a pH-neutral soap (specific to the brand) for cleaning. Every year or two, you might want to wipe on a "maintenance oil" to refresh the sheen.

  • Repairability: Excellent. This is the superpower of Hard Wax Oil. If you scratch the table, or if your child draws on it with a sharpie, you can sand just that spot, rub in a little more oil, and buff it off. It will blend seamlessly with the surrounding area.

  • The Reality: You can keep a HWO table looking brand new indefinitely without ever needing to strip the whole table and start over.

Summary Comparison

Feature

Polyurethane

Hard Wax Oil

Protection Type

Surface Film (Armor)

Penetrating Bond (Saturation)

Tactile Feel

Smooth, slick, coated

Natural, velvety, organic

Visual Sheen

Satin, Semi-Gloss, or Gloss

Matte or Satin

Water Resistance

High (Waterproof)

Moderate (Water Repellent)

Scratch Repair

Difficult (Requires full refinish)

Easy (Spot repairable)

Maintenance

Zero maintenance until failure

Occasional top-up required

Which one should you choose?

Choose Polyurethane if:

  • You want a "set it and forget it" table.

  • The table will be used for heavy-duty crafts, by young children with frequent spills, or in a high-traffic commercial setting (like a restaurant).

  • You prefer a higher gloss look.

Choose Hard Wax Oil if:

  • You love the feeling of natural wood and want a matte aesthetic.

  • You like the idea of being able to fix scratches yourself in 5 minutes.

  • You want an eco-friendly, natural product that ages gracefully with the furniture.

Both finishes meet my high standards for quality, and both will result in a beautiful custom piece. It simply comes down to how you want your furniture to feel and how you plan to live with it.

Peter Jonnes