I just finished and delivered a walnut table. I had to go back to the couple's house because they noticed spots on the table.
I used PMK woodworking's 50/50 wipe on poly method. I put about 24 thin coats of oil based polyurethane on, then sprayed the last coat.
The spots look like finger tip marks. I sanded the heck out of this table with 80, 120, 150, 180. Nothing was ever spilled or set on the top during sanding and finishing.
I know it's a long shot but does anyone have any idea what went wrong? I feel sick knowing that this happened to this awesome table.

Eddie