I always seem to get a dull spot in the center of the inside of a bowl when using shine juice. No doubt due to the inside center most spot, not spinning fast enough to make the finish stick. I like to use zinser sanding sealer and shine juice made out of equal parts of shellac+alcohol+walnut oil or BLO. The results are fairly consistent on smaller bowls and vessels (10" diameter or less); but always seem to have to hand rub the center point to get a matching shine on it. Any advise would be appreciated.