The result of Brush or spray can be comparable if you take time with brush strokes. You don’t have to worry about brush strokes or fibers from the brush getting into the finish when you use spray polyurethane. Sprays require a good technique to avoid drips and extra prep time to protect surfaces from overspray. It’s important to apply the polyurethane in thin layers that dry fast and don’t leave visible start and stop lines. I would suggest using what you are comfortable with, both methods have pros and cons. If you are applying Polyurethane for the first time my suggestion would be to use brush because it is beginner friendly compared to spray. Polyurethane that has not been properly cured might cause breathing issues and should be handled with care.
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