Waterborne polyurethanes usually require a minimum of 3-4 coats to be effective. Although there is some evidence that too many coats can result in a plastic-like finish, waterborne polyesters are thinner than other types and therefore require several more coats to provide the same protection for hardwood floors.
Two coats of finish are suggested for most interior projects. When sealing floors, you should apply three coats. However, do not apply more than two coats in one day. 220 grit sandpaper should be used between coats to remove any air bubbles, but avoid using steel wool.
Layering for Extra Protection. For floors that experience heavy foot traffic, layering multiple coats of water-based polyurethane can provide extra protection. Aim for at least three coats, allowing each layer to dry thoroughly before applying the next.
Two coats of oil based Polyurethane are recommended on stairs. For added step protection and slip-resistance, opt for three coats, while water based polyurethane, you can apply four or more coats. Wait for at least 8 hours before reapplying oil-based Polyurethane and 2 hours for water-based polyurethane.
- Use 120-grit sandpaper to gently sand the damaged area and about 2 inches around it. This helps the new polyurethane adhere better. - Follow up with 220-grit sandpaper for a smoother finish. - Be careful not to sand too deeply into the wood. Vacuum and Wipe Down: - Vacuum the sanded area thoroughly to remove dust.
Do I need to sand between coats of polyurethane? Yes, sanding between coats is important.
Prepare the polyurethane by reducing it about 10 percent with mineral spirits, unless you're using water-based polyurethane, which doesn't need thinning. Thinning the polyurethane makes it flow on more smoothly and reduces brush marks. Quick Tip!
Polyurethane will dry to touch in 3 hours. Under ideal drying conditions, allow 6 hours before recoating. Overnight drying is recommended.
No. Urethane-based product must be sanded before anything goes on top of it. Since it is essentially plastic it requires a mechanical bond between coats.
As a general rule, polyurethane can take as long as 30 days to completely and correctly cure. It would be best to give yourself a full 3- days before using your wood floors following a polyurethane treatment for the best possible outcomes.
Urethane wood flooring
The polyurethane finish dries much faster than oiled finishes, so you can expect to be walking on your new living space in only 4-6 hours after it has been applied.
Lambswool Applicators
The method recommended for applying oil-based polyurethane to hardwood floors is with the use of a lambswool applicator on a wooden block. One word of caution with lambswool applicators: The fibers of these applicators have a tendency to get stuck in wet finish.
Never more than 3 coats. First coat should be thinned 50% with mineral spirits for good penetration then two full strength, sanding between coats. When applying wipe on varnishes, double the coats.
Instructions for Applying Your Polyurethane Finish
Abrade the finish/floor in between coats, but do not buff the final coat! Usually you'll need about 3-4 coats to fully protect the floor, one or two seals, and two finish coats. Make sure to keep a wet edge while applying with a t-bar.
You should use an automotive polishing compound and a buffer for big areas. Small areas will have to be polished by hand unless you have some funky buffing tools. Make sure the poly has cured for a minimum of 4-5 days at 70f. Do not try to polish an uncured film.
One evenly spread coat will make your furniture water resistant. Most furniture builders, however, will put on three coats, with a very light sanding using 0000 grit steel wool, then using a tack cloth to remove any dust before applying next coat.
Make sure to sand the polyurethane between coats. Sanding removes drips, bubbles and other uneven spots in each coat. Dry the first coat for a full 24 hours. If the coat feels tacky or sticky after that, let dry until it feels completely dry.
If your existing urethane finish needs extra protection but not a total refinishing, you can re-coat it with Minwax® Helmsman® Spar Urethane, provided you follow the three rules for re-coating: clean, dry and scuff. First, clean off any wax and dirt with a cloth dipped in mineral spirits.
The window of opportunity to add more coats is 24 hours. The only window of danger is if you go past 24 hours. You must then sand and apply another coat of color before clearing.
Regularly clean the floor with a damp mop and avoid using harsh chemicals. For spills and stains, clean them up immediately. You may need to reapply a coat of polyurethane every few years to maintain its durability.
I prefer to use a wipe-on poly because it goes on thinner and does not leave the brush marks. You could sand what you have to smooth it, then thin the poly about 50% and use it as a wipe-on. Using it as a wipe-on applies it in a thinner layer and with it thinner it will also dry faster.
Use a Roller on Large, Flat Surfaces
rollers lets you apply the poly fast and evenly. No brushstrokes, puddles or thin spots.
Sand it with 220 on a foam block, vacuum off, sand with 400, vacuum, 0000 steel wool, vacuum, tack rag, and apply your final coat with a wide foam brush. Before my "final coat", even if my previous coat was perfect, I sand with 400-600 and 0000 steel wool to make it silky smooth before that last coat.
Water-based polyurethane is a popular choice for homeowners seeking a durable and eco-friendly floor coating. This finish is known for its low-VOC content, making it a safer option for families and pets. It dries clear and resists yellowing over time, ensuring your floors maintain their beauty for years.