A month or two ago a self pressed pintail started delaminating in the rear. A clasmate suggested to dilute the glue with water for the same reason/result (5 parts glue 1 part water.)
In the end it did help a little to get it into the cracks, but because the glue on the outside (more exposed to air) dried quicker than the glue on the inside it trapped the moisture inside of the board.
End result: The tip of the tail held strong, but the the bit behind the tail showed signs of delamination.
Also, my teacher told me that he prefers epoxy resin over regular wood glue for glueing pieces that already have lacquer on it because of the moisture.