PURPOSE: To prevent the void formation in boiled fish paste attached to a wood board, by coating the board with a specific mixture before placing the paste, thereby forming a non-permeable thin film to the surface of the board.

CONSTITUTION: The upper surface of a wood board 4 is coated with a mixture composed of 40vol% of 95% ethyl alcohol, 40vol% of propylene glycol and 20vol% of glycerine, which is supplied from a tank 2 through pipes 5, 6, 7 to an applicator 8. The coated board is transferred to the left by a conveyor 3, and the excessive mixture is wiped off with a wiping felt 9. The remaining mixture is spread over the whole surface of the board and permeates into the board. By evaporating the ethyl alcohol, the board is covered with the propylene glycol, etc. and the transmission of air and water vapor through the surface of the board is inhibited. A lump of fish paste is placed on the coated surface of the board, and heated to obtain the boiled fish paste attached to board, free from voids at the interface of the board and the paste.