You will probably want to protect most projects you make with a finish. But applying a wood finish doesn’t have to be complicated. Let’s look at the basics.
Let’s start out by getting this out of the way: Contrary to what many woodworkers will tell you, not all projects require a finish. For example. there is no huge benefit to applying a finish to shop projects, say storage or tool cabinets, tables or workbenches. Of course, if you have a lot of visitors and like to show off a beautiful work space, then by all means, spruce up your shop fixtures. I like to paint some of my shop cabinets because the bright colors make me happy and brighten up my mood!
Product links to my wood finishing materials:
- Tack Cloth
- Mineral Spirits
- Wood Finishing 101 – book by Bob Flexner
- Understanding Wood Finishing – book by Bob Flexner
- Purdy White Bristle Brush
- Oil based polyurethane
- Water Based polyurethane
- Wipe-on polyurethane
- Brushing lacquer
- Spray lacquer
- Organic Vapor Respirator
- Tung Oil
- Linseed Oil
- Danish Oil
The Practicality of Paint
I believe paint is the strongest, most durable, most practical, easiest to apply finish there it. If it’s long term durability you want, go with paint. We use paint on houses because they are subjected to all kind of harsh weather conditions. Plus, the choices of colors are unlimited.
But of course, the main drawback to paint is that it hides the wood. From my own experience on YouTube, that tends to make some people cranky. There are lots of great looking examples of painted furniture and it shouldn’t be discounted as an option, but for this video I am going to focus on clear, protective topcoats only.
The distressed paint job on these cabinets is perfect for this craft room.
Why Finish Wood?
There are two main reasons to apply finish to wood projects.
- Wood finishes help to protect wood from scratches, moisture damage, spills, stains, and UV damage from sunlight.
- A finish will make wood look great. It’s very rewarding to watch the color and grain pop as soon as you apply a finish. Plus, a nicely finished piece is very tactile and just feels nice.
Polyurethane on this lacewood makes its exotic grain pattern pop.
The soft, silky feel of the finish on this jewelry box invites you to touch and feel it.
Preparing Wood for Finishing
No matter what type of finish you use, it’s important to sand your projects first. I usually start with a 120 grit sandpaper and then move up to a 220 grit paper and stop there. There is rarely any reason to sand to any finer grit because the smooth feel of your surfaces will come from the finish you apply.
Using my random orbit sander to smooth the surface of bare wood.
After sanding, make sure you remove all the sawdust from your project. Dust particles are the bane of a good finish. I like to vacuum off the surfaces, then wipe them off with a tack cloth. Then, with a cleat lint-free cloth, like an old t-shirt, I wipe everything down with mineral spirits or paint thinner. This will also highlight any dents in the wood or any dried glue you may have missed. Plus it gives you a quick preview of what the wood might look like once it’s finished.
Vacuuming off sanding dust with my shop vac and a brush attachment.
Wood Finish Choices
If you go to a home center or hardware store, you can be overwhelmed with choices. There are a LOT of ways you can finish wood. There are entire books on the subject of finishing. In this article I am only going to discuss a few of the most common finishes hobbyists might want to use.
Two Broad Categories of Finish
- Layered finish: one that sticks to the surface of the wood, kind of like paint does. This includes polyurethane, lacquer and other varnishes.
- Oil finish: one that penetrates into the grain of the wood, such as linseed oil or tung oil. There are also mixtures of the two such as Danish oil, which is a usually mix of varnish and tung oil.
In general, a layered finish will offer a lot more protection to wood, but it can look a little artificial or in some cases kind of plasticky. Oil finishes are kind of earthier: The wood looks great and more natural, but they don’t offer nearly as much protection.
Polyurethane is probably the most popular finish today. The biggest drawback is that it can be very time consuming to apply. To get a good finish, you need to apply at least three coats, which realistically might take three days.
Applying any finish with a brush is different than painting. The goal is to avoid swiping back and forth and creating streaks or leaving behind air bubbles.
It’s a good idea to pour into and use finish out a separate container rather than straight out of the can. This will help prevent contaminating the main supply. I like to start by conditioning my brush by dipping it in mineral spirits and soaking the bristles. Next, I wipe the excess off against the rim of the can or jar.
Dip the brush into the finish, all the way up to the ferrule and let it soak up as much as it can. Lightly press the tip against the can to remove any excess that might drip. A good quality brush should hold quite a bit of finish.
Don’t be shy! Dip the brush completely into the finish, letting the bristles soak it up all the way to the metal ferrule.
Tap off just the excess that wants to drip. A good quality brush will hold a lot of material.
Start at one edge of the wood and try to apply the finish in one long stroke along the entire length of the board, pressing down more and more on the brush as you get to the end, letting it release the finish the entire way.
Applying a clear finish is different than painting. Use long strokes and don’t sweep back and forth.
Fill the brush again and apply more, slightly overlapping the first stroke. Mostly, avoid brushing back and forth as if you were painting a fence. Use long, steady strokes, trying to let the finish flow as evenly as possible. Brush slowly and don’t stop to take a break until the entire surface is completely covered. If you miss a spot, skip it. Just leave it for the next coat. If you try to dab in a patch, it can look worse. Also, it’s a good idea to start with the edges and vertical surfaces then finish up with the top surface.
Overlap each stroke.
Check the back of the can to see how much time you need to let it dry between coats. It could be 5 hours or more for oil-based poly and less for water based. Dry times will also differ based on temperature and humidity. Once each coat is dry, it should be lightly sanded with 320 grit sandpaper to remove any dust nibs and help smooth the surface. Don’t drive yourself crazy trying to get every inch perfectly sanded. In my experience, polyurethane will adhere just fine to the previous layer, even without sanding. But sanding will give the finish a smoother feel.
Make sure you remove all the sanding dust before applying the next coat.
Pay extra special care applying the final coat to avoid brush marks, runs and streaks. Use a good brush.
Give the top coat extra careful attention to avoid drips or runs.
Types of Polyurethane
You can buy oil based or water based poly. Both provide excellent protection to wood and each has advantages and disadvantages.
Water based poly is a lot easier to use: It has less odor and clean-up is easy with soap and water. To clean up oil-based poly you will need mineral spirits.
Water based poly dries a lot faster than oil based poly but you will need to apply more coats. Usually three coats is fine for oil, but water-based poly will need 4 or more coats.
Water-based poly is milky when you apply it, but it dries super clear.
But the biggest difference between oil-based and water-based polyurethane is how they look on wood. I tend to prefer oil-based poly because it gives the wood a warmer, somewhat amber look that most people find very pleasing. Water based poly is really clear. Sometimes people complain that is looks like a plastic coating on wood.
Oil vs. water-based polyurethane. The oil poly is somewhat warmer.
Finally, there is a third option called Wipe-on Poly, which is just regular polyurethane that the manufacturer has thinned down with mineral spirits. You can actually make your own if you like. It’s easy to apply. Just pour some on a rag and wipe in on the wood. A wipe-on poly finish can look really great and sometimes even better than a brushed on finish. Of course, you will probably want to add more coats of it for good results.
Wipe-on Poly is super easy to use with a clean rag.
Just wipe it on! You will need to apply several coats.
If you’ve watched my show for any length of time, you know that my favorite finish to use is lacquer. It looks great and dries incredibly fast. With lacquer you can finish an entire project in a few hours, even faster for small projects.
Almost all wood furniture you might buy at a store is finished with lacquer. In industrial and professional production environments it is always sprayed on with an HVLP sprayer. You can learn more about HVLP spraying here. Luckily there are two easier options available for hobbyists and weekend woodworkers.
The first is brushing lacquer. Apply it using the exact same brushing procedure I described for polyurethane. The only change in technique is to brush a little faster and definitely don’t brush back and forth. Lacquer dries so quickly that it can gum up if you overwork it. Again, if you miss a spot, don’t try to fix it, just get it in the next coat. If you can, set up a backlight so that you can look across the surface as you apply the finish.
The best part about lacquer is that you don’t need to sand between coats. Rather than sitting on top of each other, each coat fuses into the one beneath it. This combination of fast drying and not having to sand allows you to build up lots of coats in a very short time.
You’ll need lacquer thinner to clean your brushes. Between coats, I like to just wrap the brush in a paper towel or rag moistened with lacquer thinner and put it in a plastic bag.
I like to lightly sand the surface before applying the final coat. This will knock down any dust nibs or drips and make the top coat very smooth.
Without question, lacquer from a spray can is my my go-to finish. It’s easy to apply: Just spray it on in a back and forth motion, being careful not to get too close or too slow where it develops drips or runs. For small projects, spray lacquer is an absolutely fantastic finish. You don’t need any brushes or lacquer thinner. Click here to learn more about my technique for getting a great spray lacquer finish.
Getting a smooth feel to your finish
After the lacquer has fully cured, say 24 hours or so, I like to smooth out the topcoat. To me, this is what separates a good finish from a great finish: one that is very tactile and feels smooth without dust nibs or other imperfections.
I almost always use glossy lacquer. To get an easy satin finish, I lightly sand the surface with a 4 aught steel wool or a gray synthetic scrubbing pad. You can actually rub a finish to a super high gloss using finer and finer sandpaper and pumice. But that’s a topic for another video. I usually just do the one smoothing because I like a satin look. Of course, you can buy satin lacquer, but you will still need to rub down that final coat if you want it to have that great tactile feel. Gloss is just more versatile.
First, lacquer can be more expensive than other finishes. Especially the spray cans. Secondly, lacquer has an very strong odor and can be harmful to breathe. Use a respirator rated for Organic Vapors and solvent filtering. Lastly, some people complain about the look of lacquered finishes, saying they look too artificial. I don’t share than opinion at all and love the look of lacquered pieces.
Use an organic vapor respirator when applying lacquer.
When you want a beautiful finish that looks gorgeous and really shows off the wood, an oil finish is a great option. Plus it’s the easiest to apply. Again, an oil finish doesn’t offer much protection to wood. It would not be a good choice for a dining table or a desk that is subjected to a lot of use. But an oil finish can be a good option for decorative pieces, say picture frames or jewelry boxes. Oil finishes are arguably the most natural looking, close-to-the wood, earthy ways to finish wood.
Tung Oil vs. Linseed Oil
There are basically two types of oil finishes: tung oil and linseed oil. They both penetrate into the wood unlike lacquer or polyurethane that builds up on top of the wood. Applying either one is easy just pour some on a rag or directly on the wood surface and wipe it in. Let it sit for 5-10 minutes, then wipe it off.
If I’m using linseed oil, I like to let it dry a couple hours, then lightly sand the surface and apply a second coat. I’ve never seen any benefit to applying any more coats than two. Let it dry overnight and you are good to go.
Tung oil can take days. Use the same wipe on / wipe off procedure as linseed oil, but let it dry 24 hours before sanding it and applying the next coat. Usually you will need 4 or 5 coats. The benefit to tung oil is that it offers more water resistance than linseed oil. So it might be a good choice for say, an end table that doesn’t get a lot of use. But if water resistance is a concern, why bother with an oil finish at all? Just use poly or lacquer.
Linseed oil on cherry
Tung oil on cherry
A third alternative that I consider an oil finish is Danish Oil. It’s actually a blend of polyurethane, and tung or linseed oil. I think it tries to be the best of both worlds and for the most part does a pretty good job but as you might expect, it doesn’t look as natural as a pure oil finish and it doesn’t offer the protection of a layered finish. In fact, a lot of people apply a topcoat of straight polyurethane for added protection.
Apply it similar as tung or linseed oil, just wiping it on with a rag. Wait 30 minutes and wipe it off. In a couple hours, apply a second coat. If you want to put a layer of poly on top, wait a few days.
There are lots of other types of finishes such as shellac and finishing wax and there are tons of different techniques for finishing wood. I hope this article has been helpful and is enough to get you started. For the most part, finishing doesn’t have to be a real chore. And, for small projects you just can’t go wrong with the simplicity of spray lacquer.
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