Fisheye and many rough spots after finishing

Q: We had our 48 yr. old oak floors refinished by a pro, sanded to bare wood and 3 coats of oil base satin poly. I complained that there were many very rough edges and swirl marks from the buffer, so the pro then buffed and did another coat of poly. This time with a different brand, Fabulon, oil also. (Not sure what brand the previous three coats were.) While applying the 4th coat he started seeing what he called fisheye, spots where the finish didn’t adhere well.

He buffed and did a 5th coat, not as bad, but still some fisheye and many rough spots. I don’t think he tacked with mineral spirits after buffing, would that help prevent fisheye? Should he use a finer screen to prevent swirls and rough spots? Thanks.

A: Everything we do when sanding and coating floors involves scratching the wood and the finishes to gain adhesion. The aim is to make such scratches fine enough that they are not visible from a standing position. I’m surprised you could see swirls through the satin. I wouldn’t use a screen any rougher than 180 grit when buffing between coats, and prefer to use even finer 220 when possible but that depends on how hard the previous coat is when I buff it. There are also newer abrasive pads created because of the swirl issue. 3M makes a maroon pad which can be used with 180 grit sanding strips and now Norton Abrasives has created a line of abrasive pads which promise not to leave such marks.

I always vacuum then wipe the floor down with a micro weave mop before coating. Wet or dry doesn’t matter. All air movement should be prevented after application so the finish will have time to smooth out before setting up.

Similar Q: Is there any other way to get rid of the tiny air bubbles in my floor besides another coat of poly? Can I sand them with 220 grit screen and then apply a wax to bring back the finish?

A: You will need to abrade the surface coating to knock down the bubbles and apply another finish coat. Make sure no air is moving across the floor while it sets up. I definitely would not recommend applying wax over this top coat. It will be very slippery and impossible to keep clean.