Q: I have just completed refinishing a 55 year old white oak floor. To remove some water spots I used oxalic acid (wood brightener). It looked great when the wood was raw, however, the water based urethane made these areas appear lighter and bleached out in appearance.
How can I have these area blend into the surrounding floor boards?
A: I think you might have to accept it and live with it. What are the options? Sand it all down again and either bleach the entire floor or stain it. How thick is the wood? It may be too thin to take this amount of sanding.