Q: The old owners refinished our floor but they are peeling, in odd and sporadic areas all over the house. Can the areas be fixed or do I have to redo all the floors?
A: I would definitely recommend a complete re-sand and finish. You are either dealing with a contamination issue between the coats of finish, or improper preparation between coats to ensure adhesion. What you apply on top of this now will only be as sound as the coatings it is sitting on, which by your comments is not stable, but peeling throughout.
Similar Q: I finished a floor in my house with Minwax stain and polyurethane and it came out great. I did a 2nd room 2 years later using same steps and same can of stuff, but the polyurethane is chipping/peeling in spots. Was the polyurethane too old? Can I fix just the little peeling spots?
A: If you applied more than one coat of finish either you didn’t buff or scratch sufficiently between coats or there was a possible contaminant on the floor. Believe it or not, but it is true, even typical vasol or mineral spirits bought at the store which one may use to clean their brushes and applicators may be recycled and contain other ingredients that are contaminants.
You could attempt to fix the spots, but I might do the entire floor again if there are many.by