I'm renovating a house built around 1900. As best we can tell the pine floors are close to original.

In the three bedroom the previous owner rubbed a dark stain into the wood (after sanding) and left it like that without any further protection. The rest of the house floors looks like they have a semi-gloss clear urethane covering that's about 30 years old.

I've done a test sanding on the floors which had the clear urethane applied and those boards look lovely without any blotches.

However, the pine boards where the dark stain was applied show blotches in the wood even after sanding.

(I've got photos of both sets of boards but am getting an error while posting them).

My question is are the blotches -- which I'm guessing are coming from the dark stain applied by the previous owner -- likely to come out when our floor Pro does a real sanding? Or are the blotches so deep in the porous pine that I'm just going to be stuck with them?

Lastly, would it make any sense to refinish the bedrooms -- which have the blotches -- in a dark color while sticking with a clear, oil, semi-gloss polyurethane in the rest of the house?

All advice appreciated.

Thanks, Drew

Pine floors without blotches

Pine floors with blotches (ignore the different urethane types please)