Seal-Once NANO Penetrating Wood Sealer

Made by U-C Coatings


Protect & stabilize wood from damage and decay. Seal-Once Nano forms a flexible breathable barrier, allowing wood to age naturally.

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What is Seal-Once NANO Penetrating Wood Sealer? 

Seal-Once Nano on a new homeSeal-Once NANO Penetrating Wood Sealer® protects and stabilizes wood against water damage and decay. The water-based formula uses a proprietary nanotechnology silicate formula that forms 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. Nano extends the natural life of wood. It is non-film forming and will not alter the natural beauty of the wood.

NANO preserves the integrity of the wood by inhibits 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 NANO technology 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.

Seal-Once Nano Features 

  • Eco-friendly
  • Non-toxic; will not harm pets, plants or people
  • Ultra-low VOC
  • Water-based formula
  • Non-film forming, flexible, breathable barrier that will not peel
  • Prevents warping, cupping, wood rot & decay
  • Prevents mold & mildew growth
  • Soap & water cleanup
  • Enhances natural grain of the wood

Available Colors

Seal-Once Nano clear color

Seal-Once Nano Light brown color
Light Brown

Seal-Once Nano Natural color

Seal-Once Nano brown color

Seal-Once Nano Dark Mahogany color

Seal-Once Nano Deep Redwood color

Seal-Once Nano Bronze Cedar color
Bronze Cedar

Seal-Once Nano cedar color

Seal-Once Nano Black color

Seal-Once Nano Coastal Gray color
Coastal Grey


Note: Tints are shown on Red Cedar. The clear finish (not Natural) will not have UV protection, but will have the same great waterproofing and warranty.

Recommended Applications of Seal-Once Nano

Seal-Once Nano is designed to be used on unfinished interior and exterior wood surfaces including:

  • Cedar Shingles
  • Wood Siding
  • Exposed Beams
  • Fences
  • Planters
  • Outdoor Furniture
  • Play structures
  • Plywood
  • Pressure Treated Wood
  • Architectural Millwork
  • Woodwork


  • Seal-Once Nano on a log home

Seal-Once Nano Product Facts

Application Temperature Range

45-95° F (7-35° C)

Surface Preparation 

  • 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 Seal-Once All Wood Cleaner.
  • After cleaning, test absorbency of the 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. 

Application Notes 

  • 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.
  • 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 the first coat has penetrated but is still damp. Second coat must be applied within one hour of applying the first coat.
  • For best results, apply in the shade and out of direct sunlight.

Coverage of Seal-Once Nano

Estimated coverage: 200-300 SF per gallon per coat. Actual coverage may vary due to the porosity and dryness of the wood surface. 

Drying Time

  • Allow approximately 2-3 hours for the surface to dry, depending on temperature and humidity.
  • Allow 12-24 hours for full cure, depending on temperature and humidity
  • When re-coating, apply once the previous coat has penetrated and the surface is damp, not wet. Second coat must be applied within one hour of applying the first coat. 

Cleanup and Storage

  • Clean all application equipment with warm soapy water.
  • Store above 32° F (0° C) to protect from freezing
  • Shelf life (unopened): 3 years


Soap and water cleanup; no special disposal procedure needed.

Seal-Once Nano on a home fence

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