Top Exterior Wood Finishes for a Stunning Look

Exterior Wood Finishes: After a Decade of Trial and Error

I started finishing outdoor projects about twelve years ago. In that time I have tried pretty much everything short of leaving wood completely raw. Some worked great. Some were disasters. Here is what actually survived.

First, the honest truth: no exterior finish lasts forever. If someone tells you their product is a one-time application that will protect wood for twenty years, they are either lying or delusional. Weather wins eventually. Your goal is to make it take longer.

The Three Categories That Matter

After all my experiments, I have sorted exterior finishes into three camps: penetrating finishes, film-forming finishes, and stains. Each has a place depending on what you are finishing and how much maintenance you want to do.

Penetrating Finishes

These soak into the wood rather than sitting on top. The big advantage is that they do not peel or flake – when they wear, they just fade gradually. The disadvantage is less overall protection.

Tung oil is my favorite for outdoor furniture made from nice wood. It brings out the grain beautifully and offers decent water resistance. Needs reapplication yearly, sometimes more if you get a lot of weather.

Linseed oil works similarly but tends to amber the wood over time. Good if you want that warm, golden look. Not great if you want light wood to stay light.

Both oils need some UV protection in really sunny areas or they will break down faster. You can get versions with UV inhibitors added, or just accept more frequent maintenance.

Film-Forming Finishes

These create a hard layer on top of the wood. More protection but also more potential for problems.

Spar urethane is the gold standard here. It stays flexible as the wood moves with temperature and humidity changes, which prevents cracking. Marine-grade versions can handle truly brutal conditions.

I have a picnic table finished with spar urethane that has been outside for eight years now. It has needed refinishing twice but still looks solid. That is pretty good for something that gets rained on constantly and bakes in summer sun.

The catch with film finishes: when they fail, they fail ugly. Peeling, flaking, whitening – you have seen old deck chairs that look like they have some sort of skin disease. That is film finish failure. And the fix is stripping the whole thing and starting over, not just a touch-up.

Regular polyurethane is not great for exterior use. It does not flex enough and the UV breaks it down quickly. Use spar specifically.

Stains

Stains add color while offering some protection. They range from semi-transparent (you can still see grain) to solid (basically thin paint).

I use semi-transparent stain on cedar fences and decks. It lets the wood character show through while providing UV protection and some water resistance. Needs refreshing every two to three years in my climate.

Solid stain works well for stuff that is already beat up or made from construction-grade lumber. It hides flaws and provides good protection. Just do not expect it to look like fine woodworking – it covers the grain entirely.

Matching Finish to Project

After all my testing, here is my actual decision process:

Nice outdoor furniture from hardwoods: Spar urethane for maximum protection, or tung oil if you prefer the natural look and do not mind annual maintenance.

Adirondack chairs and similar: Tung oil. These get used and abused, scratches add character, easy to touch up.

Decks: Penetrating deck stain or oil. Film finishes on decks peel and wear from foot traffic – not worth the hassle.

Fences: Semi-transparent stain. Cheap, easy to apply, looks good enough for a fence.

Stuff that will get covered or is under a porch: Danish oil works fine. Less weather exposure means you can use lighter-duty finishes.

Application Basics

Some things apply to basically every exterior finish:

Do not apply in direct sun. The finish dries too fast, you get brush marks, and the UV starts breaking it down before it even cures. Early morning, late evening, or cloudy days only.

Prep matters. Sand properly (120, 150, 220 grit sequence), clean off the dust, make sure the wood is dry. A great finish on poorly prepped wood fails faster than a mediocre finish on well-prepped wood.

Thin coats. Always thin coats. Multiple thin coats bond better and look better than fewer thick coats.

Actually read the instructions. Dry time between coats varies a lot. Some products want light sanding between coats, some do not. Just check.

Sustainability Stuff

If this matters to you – water-based finishes are generally easier on the environment than oil-based. Lower VOCs, easier cleanup, less nasty chemicals.

The water-based exterior finishes have gotten way better in recent years. I was skeptical for a long time but I have had good results with water-based spar urethane on recent projects. Not quite as tough as oil-based in my experience, but close enough for most uses.

The Reality

Here is what I tell people when they ask about outdoor finishes: pick something appropriate for your project, apply it properly, and plan on doing maintenance.

There is no spray-and-forget solution. Wood that lives outside gets tested by rain, sun, heat, cold, and time. The best you can do is slow down the inevitable and enjoy the piece while it lasts.

That said, a well-maintained outdoor piece can last decades. I have a bench my grandfather built in the 1970s that is still going strong. Different owner, same philosophy – regular maintenance, prompt repairs, and accepting that outdoor stuff develops character.