Water-based polyurethane can be the best option for you if you want a finish that dries rapidly and has little odour or toxicity. Oil-based polyurethane can be the preferable choice if you require a finish that accentuates the inherent beauty of wood while providing enhanced durability and protection.
Water-based polyurethane has a tendency to interact more with the wood grain, which often necessitates the application of multiple coats to achieve a smooth finish.
However, there are some downsides to consider. Oil-based polyurethane has a strong odor and takes longer to dry, while water-based polyurethane, though quicker to dry and less odorous, can be more expensive.
Water based will keep the wood looking the same colour as it does now. It'll not yellow. It dries way faster and is easier to use. Oil based is more durable eventually and resistant to chemicals. If you use water based don't use polycrylic, it's the least durable polyurethane I've ever used by far.
Water-based polyurethane finish is the best polyurethane for hardwood floors, and many consider it the future of polyurethanes. High-level water-based polyurethane is as durable as oil, easier to apply, and better for you, your family, your pets, and the environment.
Oil-based polyurethane
This sort is the most long-lasting, making it ideal for outdoor projects. Depending on the weather conditions, oil-based polyurethanes can contract or expand, protecting wood in various climates and situations.
Sand Between Coats
Make sure to sand the polyurethane between coats. Sanding removes drips, bubbles and other uneven spots in each coat.
Remember, though, water based formulas tend to be non-yellowing as they age and oil based formulas tend to amber. With wood substrates that is sometimes desirable, but with many other substrates a yellowing finish is usually something you want to avoid.
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.
Water-based polyurethane finishes, provide a more consistent appearance, dry just as hard and wear-resistant as oil-based alternatives, are better for the environment and don't emit nearly the same level of off-gassing smells.
Because polyester has a much higher solid content than polyurethane, polyester's surface is stronger making it less vulnerable to scratching and chemical cleaning.
While painting over polyurethane is doable, it is a process that requires some time and effort. However, when done well, it can rejuvenate old-looking cabinets, furniture, and other surfaces.
Durability and Maintenance
Water-based polyurethane scratches and dents easily. Oil-based polyurethane coatings provide excellent abrasion and scratch resistance.
A roller is the recommended method for applying some water-based polyurethanes, as well as some oil-based polyurethanes and moisture-cured poly finishes. Rollers are good for finishing multi-direction floors, like parquets.
Here's a summary: Oil-Based Polyurethane: Wait 3 to 7 days before sleeping in the house. Water-Based Polyurethane: Wait 2 to 3 days before sleeping in the house. Natural Oils or Waxes: Wait 2 to 5 days depending on the specific product.
DURABILITY: If each product is applied properly using quality products, the difference in durability is indiscernible. A lot of clients think that water based poly is not as durable as an oil based poly, but a newer brand, quality water based poly will last just as long if it is well taken care of!
Preferred Method of Application: Direct pour the product onto the floor, saturate the roller head and then begin applying product. If you are not familiar with this technique, continue on to the “Painter's Tray” method.
Apply only one thin coat. Then, remove any dust nibs with 1,500-grit sandpaper or a piece of brown paper bag. Finally, using a soft cotton rag or polishing pad, buff the finish to a high shine using automotive paste wax, photo below, which has fine abrasives that polish the finish even further.
Water-based products do not last forever, even when unopened. General Finishes products are best used within 1 year of the manufacture date listed on the bottom of the can. The life of the product may be extended to 2-3 years with proper care and storage.
If everything was done correctly, your polyurethane surface should be ready for paint without any issues. Water-based paint works just fine if your surface is primed correctly, however it's recommended you use oil-based paint for a more superior, long lasting finish.
Typically oil-based, semi-gloss polyurethanes get that sheen from oils present in their composition. Although water-based polyurethanes generally present a lesser luster due to their chemical composition and lack of oils, there are also some of these options available.
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.
Allow product to dry a minimum of 1-2 hours between coats. Sanding between coats is not required for adhesion as long as the time between coats is less than 6 hours. However, screening or sanding between coats usually produces a smoother better looking finish. A minimum of 3 coats of finish are recommended.