Installer put in 800 sq ft of tavern grade red oak in apartment above garage. This is new construction. The installation took about two days and seemed to go well. Two different fellows showed up two days later and sanded, applied putty (tavern grade has many knot holes) and applied polyurethane all in same day. Any time I have used putty on wood I wait for it to dry before sanding. I thought it was a little odd they applied polyurethane on wet putty. They returned two days later and applied another coat of poly. The putty has cupped. It this normal? Should they have waited for putty to dry or is what they did common practice. When they finish what I thought was the second coat (contract called for three coats) I asked when they would return for third coat. They said that was third coat, that two coats had been applied the first day. How do you apply two coats when first one still wet. I have agreed to have same hardwood floot contractor apply 3" white oak to main house in about a month. Any replied greatly appreciated. Thanks Gary

Gary,
There are fillers that dry fairly quickly, and can be coated over in a few hours, if they aren't applied too thick. It's generally a good idea to apply the filler a bit proud of the surface after rough sanding. This way it is sanded flat durring finish sanding. ( the filler is allowed to dry before sanding) It seems like the filler was applied flat with a knife, and the cupping is a result of shrinkage.

Two coats of waterborne finishes can easily be applied in a day. There are various sealers that also dry very quickly, allowing a coat of finish to be applied after as little as an hour drying time.

hope this helps
Pete