After days or weeks building a project the final step can be the most difficult: which clear wood finish is best for my project?
While polycrylic’s will not yellow they are not food safe.
And food safe finishes aren’t best for surfaces like wood desk tops as they don’t seal the wood.
In this article learn the different between penetrating and surface wood finishes, what finishes won’t yellow with time, best finishes for outdoor use, and why choosing a low VOC finish is best.
Clear Wood Finishes: By Project
With hundreds of options to choose from deciding on a clear coat can be a daunting search.
And, as woodworkers know, for each project the best finish will vary.
Let’s take a look at the most common projects and wood finishes to use.
Clear Finish for Furniture or Cabinets
When finishing cabinetry or furniture pieces with a clear finish you’ll have an important decision: do you apply a penetrating oil first and then a surface clear coat last?
The answer depends on how you want to highlight the grain and if a yellowish tone on clear wood (maple) would enhance or detract.
And lastly, to avoid showing off flaws on larger surfaces most woodworkers stick to a satin finish. Why? Well, gloss finishes reflect more light and highlight defects.
Clear Coat for Trim and Window Casings
One of the most common DIY projects is to apply a wood finish to new trim or window casings.
But, surprisingly, this seemingly low surface area project will quickly turn into a tedious project as ridges and drips can create runs in the finish.
The solution? A wipe on finish that goes on easy and is great for small and large surfaces (including wood doors).
Butch Block Wood Finishes
As you likely know, the number one consideration with any food-related wood is it is “food safe”.
And fortunately there are dozens of options to choose from. Since these finishes *must* penetrate (surface finishes would come loose into your food) the options here are all oil-based sealants.
Be sure to follow the manufacturer guidelines – most of which recommend periodic re-sealants over the years. So keep hold of the bottle.
Clear Coat on Irregular Wood Project
Some finish projects are intricate enough that wiping or brushing just won’t work.
And while a professional would use an air sprayer, a DIY’er or even most woodworkers will turn to a basic spray-on lacquer.
Types of Clear Coat for Wood
From cabinets to furniture and food safe surfaces like a butcher block there are a wide variety of options when choosing a clear coat for wood projects.
But, and we’ll get to this later in more detail, there are two broad categories of wood finishes: surface finishes and penetrating finishes.
In general, you’ll use a surface finish for cabinets, furniture, trim and other surfaces as it “builds up” to provide a protective coat.
On the other hand, a penetrating finish like tung oil protects the wood from within and, with proper choice, are food safe.
Best Clear Wood Finishes for Indoor Projects
For surface finishes there are a broad variety of finishes and application types. Here’s an overview of these finish types by their primary characteristics:
- Water resistant: a urethane or polyurethane finish is best. Common for cabinets, floors, trim and furniture.
- Waterproof: an epoxy finish is most common (and durable). Epoxy is used for bar tops where water and glasses are tough on wood.
- Indoor low toxicity: to reduce the stink and chemicals, using a polycrylic or water-based polyurethane is common.
- Non-yellowing: one of the hallmarks of a polycrylic is its resistance to UV-fading and yellowing that is common with other polyurethane.
- Food safe – from (fittingly) the Tung tree, a tung oil is most popular, but mineral oil and a few other conditioners are also common.
Best Clear Wood Finishes for Outdoor Projects
Moving outdoors, you’ll find a variety of applications from direct water contact to finishes for indirect sun and water:
- Waterproof: a spar varnish is the gold standard for waterproof exterior finishes, but exterior epoxies exist as well.
- Penetrating oil: for finishing exotic woods like Jatoba there are specialty clear coats for wood furniture that are safe to use outdoors.
- Water resistant vertical surfaces: for direct sun and water contact a water based topcoat like the General Finishes 450 is popular.
Guide to the Best Clear Wood Finishes
1. General Finishes Urethane (Best Clear Wood Finish)
Urethane Wood Finishes
First, I’ve sprayed hundreds of gallons of high toxicity pre-catalyzed lacquer. And while that type of (professional) finish is fantastic, it’s not a DIY’ers option or safe to apply without the right protective gear.
So, for my home woodworking projects, 20 years ago I switched to a urethane wipe on finish (I use General Finishes, above). And the results? A comparable finish without spraying.
What do I like about a urethane finish? It holds up incredibly well to water and wear, it goes on with a cloth, dries in 15-20 minutes and is easy to sand between coats.
Like most clear finishes you will want 2-3 coats for a smooth, clear finish. And I like to use a sanding block after the first coat to create a perfectly smooth final finis
2. Polycrylic Clear Wood Finish For Interior Projects
Polycrylic Wood FInishes
A polycrylic is a water based, less toxic finish that applies easily and dries fast in the right (low humidity) conditions.
- Dries in 2-3 hours
- Covers evenly
- Cloth-based application (no brushes)
- Will not yellow like oil-based finishes
And like most clear finishes you will want 3+ coats. But for water-based finishes I recommend an extra coat. You can learn more in our guide to applying polycrylic.
3. Spar Varnish Exterior Clear Wood Finish
Spar Varnish Wood Finish
Rust-Oleum Spar Varnish is a marine grade clear finish that is great for exterior applications where the finish will be exposed to water.
- Exterior finish
- Expands and contracts with weather condition changes
- UV protection
Key drawbacks? Well, this finish is tougher to apply and isn’t suited to most interior applications. And you’ll need to use protective masks and gloves as this is a solvent based finish.
4. Clear Epoxy Resin Finish for Bar Tops
Epoxy Wood Finish
A two part epoxy forms a clear, hard wood finish that is perfect for bar tops or epoxy tops.
- Two part mixture
- Fast drying times (30-60 minutes working time)
- Avoids “fish eyes” and craters
- Bubbles can be burned off during drying with a blowtorch or heat gun
While this finish may seem intimidating, with a long working time you’ll be able to adjust your approach. But make sure you have a level surface first and a heat gun for bubble control.
5. Clear Lacquer Spray Finish In a Can
Spray Lacquer Wood Finish
First up is understanding that lacquer is an acrylic-based spray and a protective mask rated for chemical use is a must.
6. Tung Oil Clear Wood Finish for Butcher Blocks
Tung Oil Wood Finish
This penetrating wood finish can be used on a variety of projects, including:
- Food safe cutting boards
- First finish on wood projects, and then later seal them (eg. with urethane or lacquer)
- Weathered wood
- Brick, stone and cast iron
So what gives tongue oil the distinct status of a wood finish that is food safe?
Well, tongue oil is made from compressing the roots of (you guessed it) the Tung tree. Once extracted, applied to your project, it dries when exposed to air and forms a sealant deep within the wood.
7. Polycrylic Spray - Clear Wood Finish
Spray Polycrylic Wood Finish
Combining all of the features of the wipe or brush-on polycrylic but converting it to a spray can, this type of finish is quick and easy for all projects. And, as a spray can, it can be used for minor touch-ups of projects that may have been damaged during transport or installation.
What is a Clear Wood Finish?
Before we begin, let’s take a look at just what a clear wood finish is.
A clear wood finish can take two forms:
- Penetrating finish like tung oil that penetrates the wood and seals the wood pores
- Surface coat like lacquer or polyurethane that forms a layer on top of the wood
And, these can be used separately or together based on your project and desired aesthetics.
Types of Clear Wood Finishes
Now that we’ve broken wood finish into two categories (penetrating and surface) let’s take a look at what types of finishes there are in each category.
Because wood projects can range from cutting boards to furniture to outdoor benches and tables there is no one-size-fits-all clear finish for projects.
And if you factor in visual preference, UV protection, anti-yellowing, and toxicity of application there are an even wider range of finishes to consider.
Penetrating Clear Wood Finishes
A cutting board is a great example of where a clear finish is desired and the finish cannot be on the surface.
So what types of finishes can offer protection to the wood?
Fortunately there are solutions that have been used for 2000+ years (Tung oil) that are plant based and food safe.
Common Penetrating Finishes
- Tung Oil (plant-based, clear)
- Boiled Linseed Oil (plant-based, yellowing)
- Mineral Oil (non-toxic, food safe)
Applying a Penetrating Finish
These types of finishes are among the easiest to apply.
First, make sure your projects surface preparation is complete, fully sanded, and clean of all dust and debris.
Then simply follow the directions on the oil you have chosen.
A few pointers:
- Always use clean, food-safe rags if you are working with pieces like a butcher block
- Drying time can vary from a few hours to a few days with a penetrating finish
- Follow directions for multiple coats
- And, remember multiple coats can lead to build-up you may not want
With some projects, like a butcher block, you’ll be able to apply a tung oil many times over the life of the piece.
Toxicity of Penetrating Finishes
Most penetrating clear finishes are toxin free, however check the individual supplier and remember to check the actual composition. For example, some Tung oil (pressed from the Tung tree) are imitation.
Surface Clear Wood Finishes
By far the most popular type of clear wood finish, a surface finish will provide a durable topcoat.
Common Surface Finishes
Applying Surface Finishes
These finishes range from easy to hard to apply.
While some finishes wipe on with a rag, others require High Volume Low Pressure (HVLP) spray systems for the best finish.
What’s best for your project? Well, I consider budget and avoiding toxic fumes first, but humidity, drying time and your skill all play into choosing a clear wood finish.
The toxicity of finishes is something to watch.
While water-based finishes are generally less toxic than a solvent finish there are still toxins to keep track of.
What should you look for? First, the common language is Volatile Organic Compounds (VOC’s) and the Underwriters Laboratory has a GREENGUARD program that certifies products seeking to be greener.
But, be sure to always use protective equipment when finishing wood to ensure you’re minimizing contact, use ventilation, respirators and all other safety equipment as specified by the manufacturer.
Clear Wood Finish Application Tips
So you’ve decided on a finish.
Now the hard part of making sure your wood project is ready for the finish. And you have all the right supplies on hand to make the finish turn out the best.
Tip #1 - Make sure the wood is sanded properly
I’ve seen so many projects go bad with the wood not having the right finish sanding. To avoid this simply follow these steps:
- For new construction projects use a tool like a belt sander to remove extra wood and create a flat surface.
- My favorite tool is an orbital sander as it can remove a large amount of wood with a 40-grit sanding disc and be the finish sander with a 320-grit disc. Use this sander to remove any scratches and prepare the wood for a final sanding.
- Use a pad or palm sander with a high grit number (200+) to remove any orbital sander swirls.
- For uneven surfaces use a sanding block to remove any raised grain.
For help on which sanders to use refer to the guide to the best wood sanders.
Tip #2 - Use the proper safety equipment
Even a water-based finish has a level of toxicity that you should be careful with.
And lacquer or other chemical-based finishes absolutely require safety equipment. Beyond using a ventilated area be sure to use:
- Paint-grade respirator
- Chemical gloves
- Eye protection
Tip #3 - Test on a Small Piece First
I have an imprint of an orbital sander on my insulated garage door.
Many years ago I attempted a tricky color match on a maple desk top – which is extremely hard to do with a blotch-prone hard maple project. And after many redo’s and touch-ups (and a late nite) was frustrated at the process.
What I would have done different? Use a test piece of maple first, found the right application process AND THEN tackled the larger surface.
While applying a clear wood finish may not have the same level of difficulty, if you’re new to wood finishes try a test piece of the backside of your project first to get the hang of it.