Top 5 Best Spar Varnish for Exterior Wood Door

Exterior doors have a unique sense of attraction and beauty on their own. They can be an attractive way to make a statement at your front entry and give guests an idea of what awaits them in your home’s interior. Spar varnish, most times referred to as marine varnish, is created specifically for outdoor use. Since any wood left outdoors is prone to absorbing moisture and expanding, these varnishes have a higher oil ratio to resin, making them more versatile.

 Spar varnish is one of the most effective varnishes for outdoor wooden furniture and decorations. Outdoor wooden furniture takes quite a lot of abuse, so to keep the components at bay, you need to safeguard it with a good sealing material and spar varnish.

The varnish was developed to resist harsh elements like UV rays, wind, mineral exposure like salt, and even water.

With this sort of coating, your outdoor furniture items will be well protected from the harsh outdoor elements. This is why it is essential to induce the best spar varnish for exterior wood door. This article will guide you on why you need to use spar varnish and apply and opt for the best spar varnish.

Why use a spar varnish?

Why use spar varnish rather than regular varnish? What are the variations between them, and what is the purpose of each?. Most of the time, it confuses people a lot, which is why this article is for you. Let’s make it clear.

A wood that is to be placed and used outdoor has to deal with factors that would not revolve around indoor intended wood. Let’s put into consideration the constant change of humidity and temperature.

Not to mention the sun rays all over the day and alterations that your outdoor wood have to endure. And don’t forget about the vast impact rain plays.

In such cases, your wood won’t be able to sustain for long if it is a regular varnish. The contraction and swelling of your wood caused by the change in humidity alone will be enough to break down your typical varnish within a bit of time.

Choose from our Top 3 Picks

Best Buy
System Three 1855S16
Editor's pick
TotalBoat Lust Marine Varnish
Rust-Oleum 207008
System Three 1855S16 Clear Marine Spar Urethane Varnish Coating, 1 Quart Can
TotalBoat Lust Marine Varnish, High Gloss and Matte Finish for Wood, Boats and Outdoor Furniture
Rust-Oleum 207008 Marine Spar Varnish, Quart
1 Quart
1 Quart
1 Quart
Prime Status
Star Rating
Best Buy
System Three 1855S16
System Three 1855S16 Clear Marine Spar Urethane Varnish Coating, 1 Quart Can
1 Quart
Prime Status
Star Rating
Editor's pick
TotalBoat Lust Marine Varnish
TotalBoat Lust Marine Varnish, High Gloss and Matte Finish for Wood, Boats and Outdoor Furniture
1 Quart
Prime Status
Star Rating
Rust-Oleum 207008
Rust-Oleum 207008 Marine Spar Varnish, Quart
1 Quart
Prime Status
Star Rating

Last update on 2023-02-27 / Affiliate links / Images from Amazon Product Advertising API

And for this reason, spar varnish is used when it comes to varnishing wood that is to be used outside. So, no matter how the weather and other factors treat your outdoor wood, it can handle all if varnished with spar varnish.

 Now that you know that you are suitable to use spar varnish for your exterior door, you indeed are looking forward to the process. Let’s get right at it!

Before applying spar varnish, you need to;

1.Get Some Protection

Why don’t you take some protection for yourself? It is wise and advisable to put off the shirt on you. You certainly won’t like it when that gets stained. Get some protective gloves and glasses. You may also wear an aerated face mask.

2. Now Get Your Tools Ready

Varnishing requires only a few supplies that are available at your nearby hardware store. You will need –

  • Spar varnish (that’s certain)
  • A paintbrush (natural bristle brush is preferable)
  • A little stick (for stirring)
  • A clear measuring cup (small one)
  • Paint thinner (turpentine or mineral spirits)

Tip Alert: Avoid getting inexpensive brushes, which may leave stray bristles immersed in the finish and won’t spread well.

How to apply spar varnish?

The following are steps to applying spar varnish

Step 1: Slowly Stir Your Spar Varnish

Avoid shaking the container of your spar varnish. Slowly open the varnish and use your stick to reach the inside entirely.

Then begin stirring the varnish carefully with a clean wooden stick. Be as slow and mild as you can while mixing the varnish; otherwise, it may create air bubbles (produced by jabbing or squeezing the brush), so why invite trouble? That is unwanted in this case.

Step 2: Thin up Your Varnish

Pour a tiny amount of varnish into your measuring cup. The exact amount will vary depending on however large your piece is, but generally, it pays to start with little, so you can always add more. Then, add some paint dilutant or thinner directly to the varnish and stir very carefully.

Experts recommend using 20-25 per cent dilutant for the first coat of varnish and 5-10 per cent for subsequent coats. For instance, if you pour three-quarters of a varnish cup for your initial coat, add one-quarter cup of thinner. For successive cups, mix one ounce of dilutant, around nine ounces of varnish.

Step 3: Brush varnish lightly over your wood.

Dip just the tip of your brush into the varnish-thinner mixture, and gently apply it to your door. Apply varnish in the direction of the wood grain, not back-and-forth. Begin in one corner and do a one-foot square.

When that is finished, move your brush and begin another square right next to it. Repeat until the entire surface is covered. Continue dipping your brush into the varnish to keep it wet. Wear rubber gloves and a respirator if you wish to shield yourself from fumes and spills.

Step 4:  Tip-off while the varnish is wet.

 When you tip off the varnish surface, it smoothens and helps prevent any bubbles and streaks. Hold the brush at a right angle to the work surface, and lightly brush simply the brush’s tip over the whole varnished surface. Do not forget to work in the direction of the wood grain.

Step 5: Apply two coats of spar varnish, then sand and apply another

It will take at least 6 hours and probably 24 or more for each coat to dry thoroughly. After the second coat has dried, sand the piece with 320-grit sandpaper. Wipe off the excess, then apply at least one more coat of your varnish ( most wood door may need several coats of varnish).

Light wood-like trim may only need one coat of varnish. Let the final coat dry for several weeks before using the item.

But how do you know when your varnish is dry?. Varnish is dry when it does not feel crude to the touch. But if your sandpaper becomes clogged with residue, it’s a sign the varnish has not sufficiently dried. Leave it and recheck a few more hours.

Tip Alert: When working outdoors, it is essential to varnish in the morning after the dew has dried. Do not varnish in the late afternoon or early evening as it can lead to a loss of gloss and improper drying. Avoid varnishing directly when the sun is out, as this may cause the varnish to dry faster than it should.

Top 5 Best spar varnish for exterior door

Resin and oil are the ingredients that make a clear distinction in varnishes. Spar varnish, often referred to as marine varnish, is created specifically for outdoor use. This varnish has a high proportion of oil to resin.


Linseed oil and Tung oil is usually the most commonly used oils in varnish, and they produce a deep penetrating end. If your finish were solely oil, then you’d have a prolonged drying and soft finish that penetrates deep within the wood.

Using oils alone is a choice, but it takes many coats to build up thick enough skin to protect the wood. These oils are an essential part of suitable spar varnish.

As a result of adding more oil to the mixture, you get a softer and more flexible end to handle the excess movement related to outdoor wood. Higher oil content is one of the makers of perfect spar varnish.


Resins are the hardeners. Usually, the resin is either alkyd, phenolic, or polyurethane. Alkyd and phenolic are related to varnish finishes, while the use of polyurethane resin is what makes a finish polyurethane.

These ingredients produce the complex, shell-like finish you are familiar with in most varnish finishes. You’ll undoubtedly be left with a highly soft finish that may not hold up to traffic and wears without resin. Hence, selecting tough spar varnish with good resistance to a scratch is essential. Please review our list of the best spar varnishes.

System Three 1855S16 Clear Marine Spar Urethane Varnish is a coating made for marine epoxy and exterior wood finish like railings, doors, or any surface where a transparent and durable gloss finish is desired. This spar varnish has everything you’ll want: versatility, durability, top-notch protection, and longevity.

This System Three Marine Spar Varnish includes progressive UV absorbers, keeping wood looking stunning even with regular exposure to full daylight and outdoor component.

This makes the varnish thinner and helps it soak into the wood better, giving higher adhesion for the whole system of multiple varnish coats (some people will apply 8-12 coats of varnish instead of a simple 2 or 3). This coating well protects front doors exposed to daylight.

 System Three Marine Spar Varnish is resistant to spoilage as well as several cleaners and solvents. When it involves a spar varnish comparison of simple application, this coating excels among the rest.

System Three 1855S16 Clear Marine Spar Urethane Varnish Coating, 1 Quart Can
  • Available in Gloss or Satin finish. Formulated to cure properly over System Three epoxy products
  • A high solids, VOC compliant finish
  • Designed for marine and exterior wood surfaces
  • Offers excellent protection from salt air and water
  • Contains ultraviolet light absorbers which will keep wood looking beautiful even with constant exposure to sunlight

Last update on 2023-02-27 / Affiliate links / Images from Amazon Product Advertising API

It is also applied by spraying, so it doesn’t necessarily need much effort than using a brush or roller. This will give a smooth satin or gloss end without working so hard.


  • A convenient method to apply is by spraying.
  • Available in satin or gloss end
  • Protection from water and salt air
  • Has UV light absorbers to resist sunlight
  • The finish remains beautiful for a long time.
  • VOC compliant with high solids
  • Quick to dry varnish


  • Ought to know the correct proportion to avoid bubble formation

2. TotalBoat Lust Marine Varnish

TotalBoat Lust Marine Varnish allows speedy recoating without necessitating sanding between coats. It dries to a rich, warm, amber finish. It leaves surfaces shiny, and it yields a wet and sleek look. Other than the great appearance that it brings, you’ll get the surface protected by applying six to eight coatings.

Traditional spar varnishes need time-consuming sanding between coats. Other wood finishes try to mimic the exact design of varnish without the work. However, Lust stands alone.

Nearly 50% quicker to apply by spray, brush or roller. Lust’s distinct linseed oil-modified polyurethane formula provides a glossy flow-out & majorly lets you recoat in 1 hour at 72°F, eventually up to 5 coats in one day. 

TotalBoat Lust Marine Varnish, High Gloss and Matte Finish for Wood, Boats and Outdoor Furniture
  • MARINE GRADE VARNISH imparts a rich, clear amber tone that enhances wood grain; creates a durable, uv resistant, waterproof finish that won't fade; ideal for interior and exterior wood, brightwork on boats & outdoor furniture
  • CLASSIC SPAR VARNISH WITH A MODERN TWIST: High-build, fast-drying formula allows rapid recoating, multiple coats per day and no sanding between coats; sand lightly before the final coat - be done in a little over 1 day
  • FLEXIBLE COATING WON'T CRACK OR PEEL: Premium, oil-based marine polyurethane finish is not damaged when wood expands and contracts with changes in temperature; perfect for all types of wood
  • EASY TO APPLY by brushing, rolling or spraying; For a high gloss varnish finish apply 6-8 coats of Lust Gloss; for a smooth satin finish, build with coats of Lust gloss varnish; use Lust Matte for the finish coats
  • AVAILABLE IN HIGH GLOSS OR MATTE FINISH in Pint, Quart and Gallon sizes; Thinner: TotalBoat Special Brushing Thinner 100 (brushing/rolling) or TotalBoat Spray Thinner 101 (spraying); Coverage: 360-400 sq. ft./gallon

Last update on 2023-03-10 / Affiliate links / Images from Amazon Product Advertising API

Its quick to dry nature is advantageous as I don’t necessarily need to wait for a long time to the recoating. Sanding is not necessary between coatings. Hence, Its strong UV properties make it an excellent alternative for brightwork.


  • It is an oil-based premium formula with a UV stabilizer
  • It does not crack or peel
  • Quick-drying, all necessary coatings can be done in just a day
  • No sanding required between coatings
  • Has two type of finish: matte and glossy shine
  • It can be thin out or layer up as you want
  • Clear end


  • Dries up after some months in storage

3. Rust-Oleum 207008 Marine Spar Varnish

Rust-Oleum 207008 Marine Spar Varnish is a very flexible varnish that has an oil-based formula. However, it can expand and contract as the weather changes. It can even endure the harshest weather. It has a durable result which is an ideal spar varnish for outdoor furniture.

This coating can resist salt, mildew, and UV rays. Apart from the beautiful gloss and also the crystal clear finish, maximum protection is guaranteed. The surface is protected against water and chemicals. This spar varnish stands out among other exterior varnishes because of its durability. Its strength is even double the amount of the latter.

The warm golden glow that it offers is simply stunning. It takes two hours for each coating to dry, but it’s worth the wait. If durability means spending more time on the varnish, it’s not a problem then.

Rust-Oleum 207008 Marine Spar Varnish, Quart
  • Ideal for use on exterior wood surfaces above the water line, including trim, railings and wood furniture
  • Oil-based formula expands and contracts with changing weather conditions
  • Dries to the touch in 2 hours and covers up to 150 sq. ft.
  • Durable coating provides excellent resistance to UV, salt and mildew
  • Crystal-clear varnish leaves a beautiful gloss finish with maximum protection

Last update on 2023-02-27 / Affiliate links / Images from Amazon Product Advertising API

You may use a dilutant or not when using this product. Therefore, if you live in an area where there is a subtropical climate, you can use 20% to 30% thinner so that the varnish becomes runny. Then you can do multiple coatings a day.


  • Perfect for exterior wooden
  • Versatile and durable oil-based formula for deep penetration
  • Resistant to salt, mildew, and UV rays
  • The end defends the surface from water, chemicals, and sea spray.
  • It gives a warm, golden glow to the wood


  •   It takes 2 hours for each coating to dry, if not more
  • It is flammable
  • It has an unpleasant odor

4. Epifanes Clear Varnish

Is the dangerous UV light your concern? If that’s the case, then here’s the most effective spar varnish for wood to help safeguard your wooden structures against those rays.

Epifanes Clear Varnish is a bright marine spar varnish for use on wood. It is a natural spar varnish that contains an exceptionally high proportion of solids and UV filters.

Distinctively suggested for interior or exterior use on new or bare wood above the waterline and a maintenance finish on existing varnish systems. Perfect for any external application, including doors, trim and exterior furniture.

Oil-based Epifanes Clear Varnish provides quick build-up on an incomparable finish coat all in one can. This varnish quickly spreads and flows nicely to eliminate most if not all traces of brush marks.

Its low VOC (volatile organic compounds) or high solids formulation produces a highly flexible finish that provides fast build-up and gives your wood door years of protection. Besides, it helps maintain the natural beauty of the wood by exposing the wood grain.

Epifanes Wood Finish Matte (500 ml) Package may Vary
  • High build, hard matte finish without sanding between coats. (if recoated within 72 hours)
  • Soft matte beauty with outstanding U.V. protection for teak and other fine hardwoods.
  • One component varnish based on phenolic-modified alkyd resin and tung oil.
  • Microscopic porosity properties allows no sanding between coats for up to 72 hours.
  • Matte Finish giving a rubbed effect look.

Last update on 2023-03-10 / Affiliate links / Images from Amazon Product Advertising API

Because of its unique flow, superior gloss and depth, optimum weather durability, resistance to water and gloss retention, this varnish is universally acknowledged to be the finest clear finish attainable.


  • Suitable for exterior doors, furniture, etc.
  • Made of high-quality elements
  • It gives a durable and solid rock result
  • It portrays an extraordinarily glossy and clear finish
  •   It can be applied in four different methods
  • Necessary application is relatively lesser.
  • Best for hardwood or softwood.


  • Multiple coats are needed to get the best results.
  • It requires hard work when applying to horizontal surfaces

5. Minwax 630500444 Water Based Helmsman Spar Urethane

This is a widely used product for woodwork, furniture, cabinet, panelling accessories, and doors. It is a transparent gloss formula that bears special oils specially formulated to guard wood against nature’s harshest conditions.

With these components, this spar varnish can swell and contract with the wooden surfaces. The change in weather, temperature, and season won’t be a hindrance any longer.

Minwax Water Based Helmsman Spar Urethane, Quart, Satin
  • PROTECTIVE CLEAR FINISH – Minwax Helmsman Water Based Spar Urethane is a crystal clear wood finish that is specially formulated to protect against nature’s toughest conditions.
  • EFFECTIVE YEAR ROUND – This wood varnish forms a protective barrier against rain and moisture to protect your projects and keep them looking their best. Special oils allow the finish to expand & contract with the wood as seasons and temperatures change.
  • VERSATILE – Ideal for use on doors, windows, trim, bathroom cabinets, bar tops, kitchen countertops, outdoor furniture and more. It’s a versatile water-based spar urethane that dries quickly and cleans up easily with warm water.
  • SATIN FINISH – Give your wood projects a sleek finish with this satin clear varnish. It protects the natural beauty of the wood and offers a soft, unique sheen for a modern, cozy, and on-trend look. It’s ideal for use over light colored woods and stains.
  • A BRAND YOU CAN TRUST – Minwax is America’s leading brand of wood finishing and wood care products. Since 1904, we have been inspiring consumers to Keep on Finishing. We offer consumers a complete line of products to meet every wood finishing need.

Last update on 2023-03-10 / Affiliate links / Images from Amazon Product Advertising API

The transparent gloss finish won’t subject to greying and fading due to the UV blockers. Once applied to the wood, it builds up a protective barrier against wetness and rain. With the said characteristics, it is undeniably an essential part of any water vessel maintenance.


  • It contains UV blockers to reduce the sun’s greying and fading effects.
  • Build up a protective barrier against rain and moisture.
  • Special oils allow the finish to swell and contract with the wood as seasons and temperatures change.
  • Perfect for use on doors, windows, trim, bathroom cabinets, bar tops, kitchen countertops, outdoor furniture.
  • A crystal clear finish is ideal for use over light-colored woods and stains.
  • Dries up quickly and cleans up easily with warm water.


  • Makes the wood appear a bit darker

Care and Maintenance

Although spar varnish is entirely consumable, you still need to be conscious of how you carefully take care of it. In this part, you have to be familiar with the varnish by reading the label. Pay attention to the precautions for everyone’s safety.

 Bear in mind that spar varnish is highly flammable. Thus, it ought to be far from the reach of kids. Do not place it near open flames, hot surfaces, sparks, and of course, direct heat. Smoking beside it is harmful to your lungs. It’s like giving yourself ailments as you inhale dreadful substances.

Conclusion – Best spar varnish for exterior wood door

When it involves safeguarding wood and an exterior door application, spar varnish is simply the best varnish to getting a plain and simple finish. Just like you need the right tool for the right job, you also need the proper varnish to get your desired finish.

Varnish application is advisable to give your dear door maximum protection, which is why investing in the best spar varnish is a wise move.

Choosing the ideal product, tool, equipment, and spar varnish can prolong your door’s good condition. With spar varnish, there is a guarantee that protection against damages is provided. It safeguards wooden surfaces perfectly.

A spar varnish can obstruct the aggregation of mildew and mold as well as water penetration and inevitable wear and tear. It does a beautiful job of giving a fascinating and captivating appearance to your door.

We hope that this article will help your quest, serving your purpose and application well. After you read this review, you’ll surely know what’s best for your door.

Important Reads: