Hello, I'm an expert in coatings and finishes with a background in both residential and commercial applications. When it comes to applying a water-based polyurethane over oil, there are several factors to consider.

Firstly, it's important to ensure that the oil-based finish is fully cured. If the oil-based finish is not completely dry, the water-based polyurethane may not adhere properly, leading to issues such as peeling or an uneven finish.

Secondly, the surface needs to be clean and free of any contaminants. This means removing any dust, dirt, or grease that could interfere with the adhesion of the new finish.

Thirdly, it's often recommended to scuff sand the surface lightly. This can help to provide a better mechanical bond for the water-based polyurethane to adhere to.

Fourthly, while it's generally possible to apply a water-based polyurethane over an oil-based finish, it's always a good idea to test a small, inconspicuous area first to ensure compatibility and that you're happy with the results before applying it to the entire surface.

Lastly, always follow the manufacturer's instructions for both the oil-based and water-based products, as they may have specific recommendations or requirements for application.

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Products like Parks Water-Based Polyurethane for Floors can be applied over oil-based poly ... however, you must buff sand the entire floor to break the existing gloss and completely remove the sanding dust before application.read more >>