Everyone wants to find greener, lower VOC products for their home, but is water-based polyurethane something you should use on your wood floors or other projects? I get this question a lot. Water based polyurethane, or polycrylic as it is sometimes called, is a vastly different product than oil-based polyurethane. Sure they share a slot of similar characteristics but the chemical makeup, performance, odor, and appearance are factors you need to take into before you know which one is right for you.
For decades, oil-based polyurethane has been the gold standard for finishing wood floors and other wood projects. It creates a hard finish that can stand up to years of foot traffic with minimal care other than regular cleaning. Recently, government regulation has made it difficult or impossible to find these oil-based products in a few areas (sorry California!) and so the topic has come to a head for those of you who no longer have access them and are wondering about your water-based options.
In this post I’ll discuss the differences in the two products and how to work with water-based polyurethane if you choose to go that route.
Water-Based vs Oil-Based Polyurethane
Polyurethanes were invented in the 1930s and have found their way into many home improvement products like foams, glues, finishes, and caulks. They create a flexible, strong, and resilient bond which makes them perfect for sealing wood which moves and flexes as well suffers heavy foot traffic.
Prior to the introduction of polyurethane to wood finishes most varnishes were simply alkyd varnish which created a nice hard finish, but the addition of polyurethane resin to the formula added scratch, heat, solvent, and water resistance to the varnish, vastly improving the life and performance of the finish.
Water-based polyurethane is technically a misnomer since polyurethanes are an oil-based product. Water-based polys use an acrylic resin just like water-based paints. This resin is hard but doesn’t provide the same protection as the oil-based resin which is far more resilient to wear and especial heat. Below I’ve outline some of the key differences between the two products.
- Solids Content: 30-35%
- Price: $50-60 per gallon
- Color: Clear
- Dry Time: 1-2 hrs
- Clean Up: Water
- Coats Needed: 4
- Solids Content: 45-50%
- Price: $30-40 per gallon
- Color: Amber Hue
- Dry Time: 12-18 hrs
- Clean Up: Mineral Spirits
- Coats Needed: 3
Still the best for high traffic areas like floors and heat resistance oil-based polyurethane has a higher solids content which means more leftover materials to seal and coat your wood when everything is dry which is why you can get away with only three coats versus the four coat minimum required with water-based polyurethane. It adds a warm amber glow to the wood which I can appreciate and has a tendency to bring out the character of the wood nicely. Strong, reliable, and tested oil-based polyurethane is still my choice.
- Wood Floors
- High Traffic Areas
- Table Tops
There are two huge benefits of water-based polys to me and those are the ease of clean up and the quick drying. Nobody likes cleaning up with mineral spirits so using water is a big bonus. And sure you’ll have to put more coats of water-based poly on to get the same protection as oil-based poly but when you can re-coat in hours rather than a day that takes some of the sting out of it. For sealing projects where you want a truly clear finish a water-based polyurethane is one of the best options because it doesn’t give you that warm amber of the oil-based version. Good for specific projects water-based polyurethane should definitely be in your arsenal if it’s the right project.
- DIY Projects
- Light Colored Woods
- Anywhere Low VOC’s are Needed