Let me guess – you’ve finished a woodworking project, and absolutely love the way it looks. Finish seems like a risk; what if it changes the color, or doesn’t dry right, or something else terrible happens? Can you just… not finish it?
I’ve been there. And the answer is yes. Sometimes.
Wood can be left unfinished if it won’t encounter weather, water or significant handling. If your project is placed outside, will be somewhere wet, or will be used on a regular basis, then you should apply wood finish.
There’s a bit more too it, though, so let’s dive in!
Note: This blog contains affiliate links. If you click and make a purchase, I may receive compensation (at no additional cost to you.)
Outside Vs. Inside
This one probably seems obvious, but if your wood will spend any time outdoors, it needs to be finished. There are many things that destroy wood outside, including:
- Rain/snow/tornados/hurricanes/wildfires (admittedly, wood finish probably won’t save your project from that last one.)
- Bugs! Bugs like to eat wood, and anything you can do to slow this process will help your project live a little longer
- Animals! There probably aren’t any beavers in your backyard, but even a deer can knock something over and damage it.
Some woods have anti-rot properties, like cedar. Yes, this helps the wood reduce rot. But cedar and wood finish make the project last even longer.
Pro Tip: If you’re building a garden bed or planter thing, you might be concerned about wood finish poisoning your future plants/edible foods. Because of this, many people just use cedar alone, and don’t finish the wood.
While this is fine, your wood will last longer if you finish it first. Wood finish is non-toxic when fully cured (see all the details about that here,) so given that you let the wood finish dry for 30 days, it should be safe.
Also, cedar is expensive. I built this outdoor sofa out of cedar, and practically had a breakdown in the checkout line at Home Depot. You’ll cut the cost of your project in half if you used finished pine instead of unfinished cedar.
Pro Tip 2: If you’re wondering about pressure-treated wood, the “treated” part of that is chemical. I’d skip it for gardening projects, and anything that will come in direct contact with humans or animals.
Water: Wood’s Worst Enemy
Remember when you were a kid and your parents harassed you to use coasters? No? Just me?
Either way, they had a point. Water damages wood. Wood finish is a helpful barrier that at least prevents this a little. If a flash flood turns your house into a swamp, it probably won’t save your hardwood floors, but wood finish helps protect against minor water exposure.
Therefore, if your wood project will be living anywhere it could get wet, you should finish it with wood finish.
In the bathroom? Steam will cause condensation. Finish it.
Near a sink? It’ll get splashed on. Finish it.
On a surface that you regularly drink at? Spills happen. Finish it.
Wear and Tear
The first purpose of wood finish is to protect against moisture. The second purpose of wood finish is to protect against blunt trauma.
Sometimes that’s blunt trauma by knife. Sometimes that’s blunt trauma by crayon. Things happen.
Either way, if your wood piece is going to be handled regularly (aka, is a piece of furniture) it should be finished. Even if you don’t have kids. Adults damage things too.
As an example, I made the poor decision to finish the exposed wood of this nightstand with wax. Wax is a terrible finish and offers no protection. I knew that, but did it anyway. Poor choice.
This nightstand sits by my bed, and every night I open the drawer to grab my contacts case, hand lotion, and lip balm. I use them, throw them back in the drawer, and shut it.
But at the end of this process, my hands are a bit oily, since you know, I just lotioned them. And guess what? The top drawer now has all these little fingerprint smudges on it where I push the drawer shut.
I can fix it. Maybe someday I will. But wouldn’t it be better if I just used finish in the first place?
When You Can Skip Wood Finish
This is the moment you’ve been waiting for… yes, sometimes you can leave wood unfinished.
You can do this when the piece A) won’t be outside, B) won’t get wet, and C) won’t get handled regularly.
So then, when is that?
First off, art projects. This could be wall hangings that are up and out of the way, or sculptures that sit on a high shelf.
That said, sometimes wood finish enhances the look of the piece, and might be desirable even in this situation. Obviously, that’s for you to decide.
You could also skip the finish if you’ve got an indoor piece that won’t be exposed to water, and you don’t mind it looking rustic.
If dents, scratches and discoloration are part of the charm, then it won’t be a big deal if you don’t finish the piece, given the wood isn’t exposed to water.
Similarly, if you’ve got an organizer that’s hidden away, you probably don’t mind if it gets a bit dented. This drawer organizer would’ve been a pain to finish, and if it gets a few dents, well who cares? It’s in a drawer!
So Then… Which Finish?
Hopefully, you don’t have to finish your project (that’s what you were hoping for when you opened this article, right?) But if you do, here’s the quick version of which finish you should use (you can find the long version here.)
Oil-Based Polyurethane is the most durable wood finish, and will stand up to trauma and water exposure the best. But it takes forever to dry (like, 24 hours between coats. You’ll be finishing for a week.)
Water-Based Polyurethane dries faster, but is more finicky. Practice on some scrap if you go this route.
Pre-Mixed Shellac (aka, Zinsser’s Shellac Sealcoat) is hard to screw up, and dries quickly. But it’s super shiny, and doesn’t stand up to alcohol.
100% Oils look pretty, but offer no protection. Use on cutting boards, but not much else.
“Danish Oil Finish,” “Tung Oil Finish” and other things called “oil finish” that you find at home improvement stores aren’t actually oils. They’re thinned polyurethanes that also contain a little bit of oil. Like oil-based polys, they take forever to dry, and because they’re thin, require many coats to build up protection.