Oil-modified polyurethane, whose solids are a mix of alkyd resins and plastic (polyurethane), is a tough solvent-resistant finish which many people consider to be inferior to the newer, water-based finishes. But because of increasingly stringent air pollution laws, the coating industry has been pouring their research and development dollars into improving waterbased finishes.
So today, good quality waterbased finishes are about equal with high-quality oil-based finishes, at least as far as wear resistance is concerned. But the acrylic resins in cross-linked waterborne finishes (such as Bona’s Traffic) provide a even tougher, more abrasion-resistant floor.
The resin themselves are probably only marginally harder, but the cross-linkers or hardeners that are added “cause the resins to cross-link from droplet to droplet, making the finish totally reactive rather than a combination of reactive and evaporative.”*
This is simply a long-winded way to say that, if you are judging finish only by how many times you can walk across it wearing your golf cleats, the cross-linked waterborne will always come out on top. Oil-based finishes still have many strengths (such as color and ease of application) than can make them superior to waterborne finishes for some applications.
So don’t just go to your local big-carton retailer and buy the cheapest waterborne, assuming it will be the better finish; its durability is likely to be poor. Buy the best quality you can afford, whether you choose oil-modified or waterborne finishes.
*Bob Flexner, Understanding Wood Finishing. Reader’s Digest, Pleasantville, NY. p.168