It is safest to use an oil-based polyurethane varnish on an old finish; the new water-based polyurethanes may not be compatible with old oil-based finishes. And, if the old finish is shellac, new ...
Q: We just stripped six layers of paint off the front door of our 1820s house. I think the door is made of chestnut. We don’t want to repaint it, and we don’t like polyurethane. What’s the best ...