Seal Once Nano

Seal Once Nano Penetrating Wood Sealer

SEAL-ONCE® NANO Penetrating Wood Sealer protects and stabilizes wood against water damage and decay. The water based formula uses proprietary nanotechnology to form a flexible breathable barrier by coating the wood fibers at the cellular level.


NANO allows wood to age naturally without decay, and can be used to preserve old or new wood, extending its natural life. It is non-film forming and will not alter the natural beauty of the wood.

NANO preserves the integrity of the wood by inhibiting rot, mold and mildew growth, and eliminates warping and cupping. NANO forms a flexible breathable barrier that allows the wood to expand and contract, and for water vapor to escape.

The advanced technology of NANO allows it to penetrate and bond to the cellular structure of the wood, forming a superior barrier below the surface to protect from the inside out. NANO goes on milky white and dries clear. It is also available in semi-transparent tints.

Product Features


Non-toxic; will not harm pets, plants or people

Ultra-low VOC

Water based formula

Non-film forming, flexible, breathable barrier

Will not peel

Prevents warping, cupping, wood rot & decay

Prevents mold & mildew growth

Soap & water cleanup

Enhances natural grain of the wood

Clear formula allows for smoother finish, more even color & easier application of water & solvent based stains & finishes

Tinted formula provides additional UV protection

Recommended Applications

Cedar shingles

Wood siding

Exposed beams



Outdoor furniture

Play structures


Pressure treated wood

Architectural millwork


Physical Characteristics

Color: Milky white liquid, dries clear
Flash Point: None
pH : 7+
Solvents: Water
lbs/gal : 8.4

Specific Gravity: 1.007
Viscosity: 3.2 cps
Application Temp. : 45°F/7.22°C* – 95°F/35°C
Odor: Nil
VOC Content : 28g/L**

*Do not apply when air or surface temperature is below 45°F/7.22°C or may fall below 45°F/7.22°C within 24 hours after application.

**VOC Content determined via EPA Method 24.

Available Colors


Light Brown



Bronze Cedar



Cape Cod Gray

Shale Gray

Battleship Gray


Packaging Sizes

1 Quart Can | 1 Gallon Can | 5 Gallon Pail | 55 Gallon Drum

Freight Class


Application Instructions


All surfaces should be cleaned before sealing for best penetration and performance. Remove all old coatings, dust, debris and loose material. Remove oil, grease, algae, grime, mill glaze and mold and mildew stains with appropriate cleaners. Recommend SEAL-ONCE All Wood Cleaner.

After cleaning, test absorbency of surface by sprinkling a few drops of water on the surface. If the water does not readily penetrate the surface, stripping will be necessary to remove old coatings prior to applying SEAL-ONCE NANO Penetrating Wood Sealer. Retest surface when dry


Do not use if air or surface temperature is below 45°F/7.22°C or above 95°F/35°C.

Do not apply in rain or when rain is expected within 12-24 hours.

DO NOT THIN. Mix well. Stir contents or shake thoroughly prior to use.

Test a small area to ensure acceptable appearance and penetration.

Apply first coat with a synthetic brush; pump-up garden sprayer; air-assisted; and/or airless sprayer. Use 15-17 tip and medium to coarse spray pattern. When spraying, always back brush for best results.

Second coat can be applied once first coat has penetrated but is still damp. Second coat must be applied within one hour of applying first coat.

For best results, apply in the shade and out of direct sunlight.

When applying in direct sunlight and wood surface is hot, spray with a mist of water and apply NANO immediately on dampened surface.

Apply to all surfaces. Apply SEAL ENDS ONCE® to wood ends.

Do not use with other waterproofing products.

Wood can be painted or stained as soon as it dries in approximately 2-3 hours, if SEAL-ONCE Semi-Transparent Tints are not being used.


Approximate coverage: 250-350 sq. ft./gallon per coat. Actual coverage may vary due to the porosity of the substrate.

Drying Time

Allow approximately 2-3 hours for surface to dry, depending on temperature and humidity.

Allow 12-24 hours for full cure, depending on temperature and humidity.

When recoating, apply once previous coat has penetrated and surface is damp, not wet. Second coat must be applied within one hour of applying the first coat.

Cleanup & Storage

Clean all application equipment with warm soapy water.

Store above 32°F/0°C to protect from freezing.

Shelf life (unopened): 3 years

Disposal: soap and water cleanup; no special disposal procedure needed.


Protect adjacent areas from overspray and runoff, including windows and siding. Immediately remove overspray with soap and water.

Avoid breathing in spray. If inhaled, move to fresh air.

Avoid contact with eyes. If splashed into eyes, rinse with clean water for 15 minutes.

If skin irritation occurs, wash area with soap and water.

If accidentally ingested, immediately drink 2 glasses of water and contact a physician. Do not induce vomiting.

Do you need assistance in choosing the right wood and cement sealer for you?

We can help you from selecting the correct product you need in your project
from its professional engineering services.

Do you need assistance in choosing the right wood and cement sealer for you?

We can help you from selecting the correct product you need in your project
from its professional engineering services.