Wax is a fine product. The question is whether to apply it over polyurethane, and the answer is no. You might want to ask this question on the flooring forum. Here is a link that might be useful: Flooring forum This post was edited by graywings on Wed, Jan 22, 14 at 9:24

Shellac will always dissolve with alcohol, meaning that if you can soak a rag in denatured alcohol and rub off the finish to the point where it changes the sheen [dull] than it's probably shellac. If it's poly I suggest staying with poly. It might also be old style [oleoresinous] varnish, depending on the age of the finish. Does it scratch easily? If it has maintained it's shine pretty well it's probably poly and i would test a spot before shellacing the whole floor.

Hello, we have a small sunroom ( western side of the house) has knotty pine wood on the walls, ceiling and up into the cut out Skylight areas. The area up in the sky light reflected drip like black water marks on it so we decided to paint the ceiling (had the skylights replaced three months ago and we know the Knotty Pine is in fine shape otherwise). We decided to paint the ceiling, including up in the recessed sky light areas. started with the Bin primer, put two coats, then started to see an Amber-colored film coming through. Unfortunately the painter then added two coats of a latex paint. The amber color is still coming through. I'm wondering if it's old sap that which from the heat of the sun coming through the skylights. Suggestions on how I tackle this project at this point considering we have two layers of den and two layers of latex paint and the amber color is coming through just like we simply did a white wash.

Oh dear. This is a problem. Wax should NEVER be applied over a finish. Ever. You will need to get down on hands and knees and remove this product. As G&S suggests you will need to reach out to the makers of Bioshield 39 and purchase THEIR floor stripper (every chemical has an 'undo' chemical....the easiest way to do this is to use the makers 'revers' chemical). It sounds like you wanted to add 'shine' to the floor. Do you have 'before' and 'after' pics?