I'm refinishing a 1940 oak floor in my neighbor's house I just bought, which is identical to my house, where I've refinished the floors also. In my house I had the same problem but on a much smaller scale. In the new house, the darker sections of the grain are either absorbing or repelling the poly (oil based Minwax) even after the third coat.

I did not test the floors for wax or oil beforehand as I sanded to bare wood (36/60/80/100/120). Floors didn't appear to have poly on them, I did find Orange Glo floor care products in the house. I stained with Minwax, which went on fine.

I expected to see uneven sheen after the first coat (gloss). Now after three coats, there are high spots where the finish is building up on the surface as expected, but nearly all the darker grain spots are dull and the finish is not building up. First coat dried about 24 hours, then 12 hours for 2nd. Third has been down over 24 hours now.

Any idea on the cause and what my course of action should be?

Thank you,
Jim
Topsham, ME

That Minwax poly does not have a very high solids content, Plus, it is commonly known that grainy hardwoods like oak and mahogany require grain filling. That being said, few of us pros actually do that on floors. If you desire a uniform sheen, all that can be done at this point is to keep applying more coats. Consider using a satin finish, which will not show scratching as much and not show that open grain as much either. Oh yeah, there is a product, a grain filler, that can be used between coats of finish. Here's the link.

http://www.berger-seidle.de/us/products ... elfill.htm

Don't ask where to buy. I don't know. It says compatible with their finishes so you may need to switch to a waterbased poly after using it.