FAQ | SEAL-ONCE©®

SEAL-ONCE products can be used on wood, concrete or masonry. This includes hardwood, softwood, pressure-treated wood, exotic wood, wood siding, log homes, cedar shakes and wood decking. Our products can also be applied to stucco, clay tiles, paver blocks, bricks, porous concrete, grout and mortar.

SEAL-ONCE NANO is a non-film forming, deep-penetrating, water based formula that creates a flexible, breathable barrier to protect wood against damage caused by water ingress. It is ideal for vertical surfaces and areas that will not be subjected to a high level of wear and tear.

SEAL-ONCE NANO+POLY combines our proprietary nanotechnology formula with the strength of polyurethane to provide 360° of protection for wood, concrete and masonry. It is ideal for high traffic applications such as decks and patios.

SEAL-ONCE NANO, MARINE, SEAL ENDS ONCE and Multi-Surface Concentrate are fully cured within 12-24 hours, depending on temperature and humidity. SEAL-ONCE NANO+POLY and EXOTIC are fully cured within 24-48 hours, depending on temperature and humidity.

Allow 48 hours drying time before it rains.

SEAL-ONCE deeply penetrates the wood surface by utilizing proprietary nanotechnology to create a flexible, breathable barrier that prevents water damage and decay and allows water vapor to escape. It is non-film forming and will not peel.

Most Seal-Once wood sealers come in pre-mixed standard colors.  If the product
you choose is only available in clear you may add Seal-Once Wood Stain Color
Tints. Add one tint bottle to one gallon of Seal-Once clear.  When using Multi-Surface Concentrate, color can be added for wood applications after the base product has been properly diluted. Seal-Once concrete sealers are clear only. Do not add tint.

No, all SEAL-ONCE products are designed for exterior use.

Yes, SEAL-ONCE products are water based, do not contain any harmful chemicals or toxins and are ultra-low VOC. Our products can be safely applied and will not harm pets, plants, people and marine life. Additionally, our products do not require special personal protective equipment (PPE) and can easily be cleaned up using soap and water.

SEAL-ONCE must be applied to bare wood. If the surface has been previously coated with another stain or sealer, that product must be removed. Common practices for preparing your wood project include power washing, using a cleaner such as our All Wood Cleaner, sanding the surface or using a stripper to remove all previous stains and coatings   Ensure all surfaces have been properly cleaned by using the appropriate SEAL-ONCE cleaner (All Wood CleanerorConcrete/Masonry Cleaner).  After cleaning, rinse the surface with water and allow to dry completely. Once the surface has been cleaned and the old coating has been removed, SEAL-ONCE products can be applied, according to the package instructions.

Yes, we recommend covering all surrounding materials and surfaces, as well as wiping down or removing all areas impacted by over-spray while still wet. While all SEAL-ONCE products are eco-friendly and will not harm the surrounding landscaping, it is advised that you cover any adjacent walls or materials that are not recommended for coating with SEAL-ONCE, especially if you are using one of our Semi-Transparent Tints.

Seal-Once may be applied with a pump sprayer, roller, flat stain pad, or a synthetic brush. If you use a sprayer, roller or flat stain pad, you must immediately brush the area using a brush. It is called back brushing. Brushing is very important. Brushing will push the product deeper into the surface for longer lasting water proofing results.

The temperature range for applying SEAL-ONCE NANO, MARINE, SEAL ENDS ONCE and Multi-Surface Concentrate is 45°F (7.22°C) to 95°F (35°C). The temperature range for applying SEAL-ONCE NANO+POLY, EXOTIC and POLY is 50°F (10°C) to 95°F (35°C). These temperature ranges apply to both surface and air temperature for wood and concrete.

The second coat must be applied while the first coat
is still damp/wet and penetrated into the surface. The second coat must be
applied WITHIN 20-30 minutes of the first coat. During warmer temperatures, the
first coat can dry within minutes.  You may need to apply the second coat
within 5-10 minutes of the first coat on hotter days.

All of our tints and stains are semi-transparent and allow the natural color and grain of the wood to show through. The color charts on our website have been created using two coats of our tinted SEAL-ONCE products on red cedar. If you are coating a different material, you may see different results. Using more than two coats will also result in a darker, more saturated appearance. The color may also vary depending on which formula you are using as the colors may appear darker or more saturated in some formulas.

We offer 4oz pre-mixed bottles of all of our semi-transparent tints for testing on the material you are coating. Samples can be purchased in our webstore.

No, only the SEAL-ONCE® semi-transparent tints have been specially formulated for our products. Other colors or pigments may alter the effectiveness of our products.

Yes, SEAL-ONCE NANO+POLY prevent efflorescence, which occurs when water penetrates the concrete and leaches out naturally-occurring salts, creating undesirable white stains on the concrete. Efflorescence must be removed prior to applying SEAL-ONCE, if it is already present on the surface.

New pressure treated wood will need to weather 3 months in warm temperatures before you can clean and apply Seal-One water proofers. Moisture content of the wood must be under 20%

SEAL-ONCE NANO, MARINE, EXOTIC and NANO+POLY can be applied to freshly cut wood because they create a breathable barrier that allows water vapor to escape as the wood ages.

No, do not apply Seal-Once to a concrete driveway or garage floor. Hot tires will “draw up”
Seal-Once from the concrete leaving un-even shiny spots on top of the surface.

You may spray, roll or brush the required 2 coats of Seal-Once water proofers. If you spray or roll, you must immediately brush the area.  It is called back brushing. Brushing is very important. You begin at the end of two boards. You will brush to the other end of the same two boards. Now apply a second coat to the same 2 boards. Apply the second coat within 20-30 minutes of the first coat or sooner. The second coat must be applied while the first coat is still damp/wet.  (Wet on wet application). Do not allow the first coat to dry. Push the product into the wood with the brush. Spread it out evenly. Do not allow it to puddle. Wipe off any excess with a rag. During warmer temperatures, the first coat can dry within minutes.  You may need to apply the second coat within 5-10 minutes of the first coat on hotter days.

Every Spring, spray a small amount of water onto your deck. If the water beads up in most areas, Seal-Once is good for another year. Seal-Once will bead and then it will show sheeting-  water repelling from a surface without beading (hydrophobic sheeting) - Larger pools of water. Both protect your deck.

No, you cannot apply stain, sealers, primer, paint, polyurethane, or varnish over Seal-Once. They will bead up and roll off.

Seal-Once products must be applied to raw bare wood. You
must completely strip off all the old coatings. You cannot apply Seal-Once water proofers over stain, sealers, paint, polyurethane, or varnish. Seal-Once will not penetrate properly.

Yes, you must prepare
your new deck using Seal-Once Multi-Surface Cleaner. Apply the cleaner as directed.  Let it sit on the surface for around 20 minutes. During this time, agitate it with a scrub brush.  The scrub brush will help immensely. Do not allow the cleaner to dry on the surface. Keep it wet. Rinse off the cleaner with a power washer.  Keep the wand about a foot away from the surface.  You don't want to damage the wood. Wait 2 dry days after cleaning before you apply Seal-Once water proofer.

No, all exterior clear products, including Seal-Once clears, will allow the wood to gray naturally.

SEAL-ONCE Marine is the original and ensures continuity of the product our legacy customer’s trust. It is produced on a smaller scale, which contributes to its higher cost. SEAL-ONCE Marine-Grade is designed for retail
scale without sacrificing performance and quality that benefits from larger-scale production efficiencies, making it more cost-effective. UC Coatings does not control the price points including any promotional periods set by our
retail partners, whether in-store or online. Products being sold via eCommerce platforms by UC Coatings, or our customers, may have slightly different price points due to various factors such as product cost, advertising expenses and shipping costs associated with the scale of the business.

Both products provide superior protection and stability on your outdoor projects for wood decks, docks, fences, and siding and meet our high standards of quality and performance.

Both products will provide superior protection and stability on your outdoor projects for your wood deck, dock, fence, or siding.

No, both SEAL-ONCE Marine and Marine Grade meet our high standards of quality and performance.

Ideally you should use the same labeled product for your
entire project to achieve consistent results. 

However, if that is not possible, in such cases as an alternative approach, mix them in equal parts before starting any application to ensure a uniform finish.

This is not recommended if it can be avoided.

If you have already started part of your project, do not finish with another.

In ALL cases and under no circumstances should a second coat be applied after the first coat is dry.