How to Finish Decks and Porches

newly finished wooden deck using Real Milk Paint's tung oil and citrus solventWhen you’re researching ways to better preserve and protect your deck, the Real Milk Paint Co. can help with high-quality oils to finish decks in complementary wood grain natural colors. Some professionals prefer commonplace options found at your local hardware store — for example, linseed oil and wood stain; however, our products offer all-natural formulations, easy application and long-term protection, making finishing oils like Pure Tung Oil and Outdoor Defense Oil your best bet to finish decks and wood porch rails.

Tung Oil for Decks

The deck you see here I built last summer. It has pressure-treated decking, cedar posts and railing with copper balusters. We allowed the entire deck to dry out and age a season as I don’t like the look of new deck wood but prefer a little bit of weathering to match our 1892 home.

Keep reading to learn how to finish decks with Pure Tung Oil from the Real Milk Paint Co. I outline the process for how I added a protective finish to my own deck while guiding you through making good decisions throughout your own deck wood finish project.

Cleaning Deck Wood Before Pure Tung Oil Application

For this home improvement project, we first cleared the deck boards with forced air from an air compressor, blowing out all the leaves and debris between the boards. Since I like the color a little weathered, there was no need for pressure washing or chemicals to clean the deck. However, I’ll outline the process: Clean the deck with a pressure washer and deck cleaner. Set the pressure washer to a low-pressure setting so as not to damage and fuzz up the wood.

The important part here is to get the dirt and grime off the wood through pressure washing. This is to ensure a clean surface for applying your first tung oil layer. At this point, if the deck surface was too gray or weathered for my liking, I could’ve used a deck wash from the hardware store or Oxalic Acid to bleach the gray. If you decide to go that route on your deck stain projects, just follow the directions for using our Oxalic Acid Wood Bleach on the product page.

Kill Mold and Solve Recurring Green Mold Issues

Next, I let the deck dry and was ready for the next step: applying a wood preservative like TimBor Wood Preservative. If you have recurring green mold issues, treat the wood grain before you apply the Pure Tung Oil finish to help control and kill mold. I recommend you apply TimBor Wood Preservative for this purpose as well as to improve the long-term protection offered by our Pure Tung Oil and Outdoor Defense Oil.

Once you seal TimBor Wood Preservative into the wood, it doesn’t come out unless the finish wears away. Most instructions to clean wood decks recommend killing the mold with bleach and water, but this only works to kill the mold on the surface and temporarily make the wood look clean. When you clean your deck wood this way, the mold usually returns in one season because it hasn’t been killed inside the wood, just on the surface.

DIYer applying the first coat of pure tung oil on deck boards

Applying Pure Tung Oil to Pressure-Treated Decking

We’re now ready for Pure Tung Oil made with tung nuts from Chinawood tung trees or Outdoor Defense Oil made with pine solvent and zinc. Before you start finishing your wooden deck, though, you should check the weather for the next few days to be sure rain isn’t in the forecast. The wood should be dry before application to ensure the oil and solvent have completely penetrated the wood, but a little dew in the morning after application doesn’t hurt anything.

Avoid Direct Sunlight While Adding Wood Stain

Keep in mind that you should only apply our oils in the shade or cool of the day (no direct sun). Direct sun can quickly polymerize the oil and leave a frosty finish. On our wood deck, we applied two coats of Outdoor Defense Oil. Since the wood had aged a season, it was pretty absorbent and drank the finish right up, with two coats applied in succession and no waiting overnight. The wood simply drew in the first coat, then we applied the second coat. All the oil and solvent completely penetrated the wood, so we could’ve applied a third coat, but due to time constraints, we stopped there.

Mixing Tung Oil and Citrus Solvent for Absorption

When adding a tung oil finish, you likely need to mix your Pure Tung Oil with a solvent such as our Orange Oil Natural Citrus Solvent at a 1:1 ratio to ensure deep, even penetration into even new wood grain. (Our Outdoor Defense Oil is already thinned, so you can skip this step.) Mix up the two all-natural products, add a tung oil layer to your deck or porch railing, then let the oil and solvent mixture soak into the wood for 40 minutes to an hour. Wipe up whatever hasn’t soaked in with clean T-shirt material to ensure a smooth finish.

Ensuring Tung Oil and Solvent Completely Penetrate Wood

Next, allow the surface to dry for a day or two before heavy use. All the oil you apply should soak into the wood, so be sure not to let oil lay on top of the wood and dry. If the oil dries on top of the deck stain surface, it creates a rough deck finish that has a slight frosty look, which can spoil the look of your wood stain.

Adjusting Oil Formulations to Suit Your Wood’s Condition

If a 1:1 mixture doesn’t soak into the wood, however, the pure tung oil mixture needs more Citrus Solvent. Conversely, if your wood is really dry, it may absorb the Pure Tung Oil straight and without much rubbing. If this is the case, simply apply the Pure Tung Oil first, then follow up with Outdoor Defense Oil.

Apply Tung Oil Instead of Deck Stain

man applying outdoor defense oil on deck instead of other oil-based stains

Pure Tung Oil from the Real Milk Paint Co. provides numerous advantages for your deck finish without the use of actual wood stain. Made from tung nuts found on the Chinawood tree, this all-natural finishing oil contains no volatile organic compounds (VOCs), letting you work in comfort and without unpleasant odors.

Once cured, a Pure Tung Oil finish easily resists moisture, abrasion and acids, and it doesn’t blister and peel when properly applied to your deck wood. Likewise, this honey-hued finishing oil has a Grade 1 yellow rating, making it the best available tung oil on the market, with freshness guaranteed thanks to daily pumping.

Count on a flexible waterproof finish with every use of Pure Tung Oil. This wood stain alternative boasts a naturally polymerizing finish, curing by oxidation rather than evaporation. This means Pure Tung Oil provides a low-luster matte finish and never gets glossy, no matter how much you add to thirsty deck wood.

The long shelf life of Pure Tung Oil also makes it an attractive option when you want an all-natural alternative to an oil-based stain. Formulated to endure for years without going rancid when properly sealed, our tung oil doesn’t mold or darken over time like linseed oil and offers FDA-approved food-contact safety for versatile use around your household.

Keep in mind that the concentrated formulation enables application of Pure Tung Oil either straight or cut at a 1:1 ratio with a solvent for better absorption power. While mixing it with our Odorless Mineral Spirits gets the job done, our Citrus Solvent is a better mixative for your deck wash in instances where increased eco-friendliness matters.

Finish Decks With Outdoor Defense Oil

Outdoor Defense Oil offers many advantages to the long-term preservation and beauty of your entertainment and lounging space, including adding more UV protection. If your wooden deck is made of the old arsenic-laced pressure-treated wood, for example, Outdoor Defense Oil seals the dangerous chemicals into the wood to reduce contamination risks.

Also, this pine and citrus-blended solvent soaked into your deck wood kills bugs and ants that might be hiding in the cracks. While Outdoor Defense Oil seals and protects the wood, it doesn’t blister and peel, so future application just requires a quick cleaning, then application of more oil.

Outdoor Defense Oil does contain zinc for natural UV protection, so it also should naturally resist mold and mildew. Additionally, the all-natural formulation designed to mitigate UV exposure also helps your deck resist graying as long as you maintain enough of the Outdoor Defense Oil finish on the wood.

Finishing Oil Coverage and Curing Times

outdoor defense oil 1Plan your oil-based deck finish easily by knowing how much coverage power our finishing oils have ahead of time. For example, with our Pure Tung Oil, straight coverage per coat measurements are:

  • 8 ounces covers 25 square feet
  • 16 ounces covers 50 square feet
  • 32 ounces covers 100 square feet
  • 1 gallon covers 400 square feet

If you want to improve protection for your wooden deck stain, Outdoor Defense containers have a complementary amount of coverage to Pure Tung Oil. Coverage amounts include:

  • Sample covers 1 square foot
  • 16 ounces covers 50 square feet
  • 32 ounces covers 100 square feet
  • 1 gallon covers 400 square feet

You can also use our oil calculator to determine the exact amount of finishing oil you need for your project.

As far as curing times go, Pure Tung Oil cures partially within 7 to 10 days and fully within 15 to 30 days. Our Outdoor Defense Oil has similar curing times, making the two products an especially powerful line of protection against the elements for your deck or porch and patio railing.