Wood finishes has gotten complicated with all the brands and conflicting advice flying around. As someone who’s been building and refinishing furniture for over fifteen years now, I learned everything there is to know about varnish, polyurethane, and Danish oil — the three finishes I keep coming back to no matter what.
When I first started woodworking, somebody at the lumber yard asked what finish I was planning to use. I just stared at him. “Finish?” I genuinely thought slapping some paint on was the whole process. I’ve come a long way since then, and honestly these three products cover about ninety percent of what most woodworkers will ever need.
Varnish: The One That’s Been Around Forever
Varnish is a mix of oil, resin, and solvent that cures into a hard protective film. That glossy coating on antique furniture that still looks incredible after a hundred years? Almost certainly varnish. That’s what makes varnish endearing to us old-school woodworkers — it just lasts.
I reach for varnish mostly on outdoor projects. It flexes slightly with wood movement, which matters a lot when temperatures and humidity are swinging around seasonally. The rocking chairs on my front porch have marine varnish on them and they’ve survived five winters without any cracking or peeling.
Application is pretty straightforward, just slow. Brush on a thin coat, let it dry overnight, hit it with 320-grit, wipe the dust, do it again. Three or four coats minimum if you want real protection. It’s meditative work, honestly — I’ve grown to enjoy the rhythm of it.
Probably should have led with this section, honestly: the big downside is yellowing. Varnish can amber up noticeably over time, especially where it’s catching direct sunlight. And cleanup means breaking out the mineral spirits, which is messy and smelly. Still, for sheer durability and that warm traditional look, nothing else quite matches it.
Polyurethane: The Modern Upgrade
Think of polyurethane as varnish’s tougher, more evolved cousin. It forms a harder, more scratch-resistant surface, which explains why pretty much every piece of furniture made in the last fifty years has it on there somewhere.
You’ve got two main choices, and I have opinions about both.
Oil-based poly adds this subtle amber warmth that looks fantastic on darker woods like walnut and cherry. It also gives lighter woods some depth and richness. Drying time runs about 24 hours between coats, and the smell is pretty intense — I usually try to finish polyurethane projects in the fall when I can leave the garage door open. The finished product though? Genuinely tough. I’ve seen oil-based poly stand up to things that would destroy most other finishes.
Water-based poly dries clearer and way faster. On a good day I can knock out three coats before dinner. The smell is barely there, which matters when your shop shares a wall with the kitchen like mine does. It can raise the grain though, which means more sanding between coats. And it’s maybe ten to fifteen percent less durable than oil-based, if I’m being honest.
For tabletops, floors, anything seeing heavy daily use — polyurethane is the answer. My kitchen table has oil-based poly on it and has taken years of abuse from my family. Homework, craft projects, that one Thanksgiving when somebody forgot a trivet. Still looks great.
Danish Oil: The One I Tell Beginners to Start With
If you’ve never applied a wood finish before, Danish oil is where to start. It’s almost impossible to screw up. It’s a blend of oil and varnish that you wipe on, let it soak for about fifteen minutes, then wipe off the excess. That’s literally it. If you can oil a cutting board, you can apply Danish oil.
The look you get is more natural than any film finish. It soaks into the wood rather than sitting on top, so the surface still feels like wood under your fingers instead of plastic. On figured woods — tiger maple, curly birch, quilted anything — Danish oil makes the grain absolutely sing. Film finishes look good, but they don’t match this.
Protection-wise, it falls in the middle. Better than bare wood by a mile, but not as bulletproof as four coats of poly. I use it on pieces that’ll be handled but not tortured: jewelry boxes, picture frames, small decorative items, shelving. My workbench has Danish oil on it because I like how it looks and honestly don’t mind giving it a fresh coat once a year.
And that’s actually the biggest advantage of oil finishes — maintenance is just wiping on more oil. No sanding, no stripping. With varnish or poly, once the finish gets damaged you’re often looking at taking the whole thing down to bare wood and starting from scratch. With Danish oil you just recoat the worn areas and move on.
Which One Do You Actually Need?
After all these years, my decision tree is pretty simple:
Need something that can survive kids, pets, and daily use without flinching? Polyurethane. Oil-based for maximum toughness, water-based if fumes are a concern.
Building for the porch, the deck, or anywhere it’ll face weather? Varnish, specifically marine or spar varnish. Nothing handles outdoor conditions better.
Want that hand-rubbed, close-to-the-wood feel and don’t mind occasional maintenance? Danish oil every time.
There are plenty of other finishes out there — lacquer, shellac, pure tung oil, paste wax, the list honestly never ends. But these three handle the vast majority of real-world projects, and all of them will give you solid results if you take the time to apply them right.
One last thing that’s saved me more grief than I can count: always test your finish on a scrap piece of the same wood before committing to the actual project. Every finish behaves differently on different species. What looks warm and gorgeous on oak can look muddy and weird on walnut. A five-minute test on scrap wood beats hours of regret, every single time.
