Abstract: A method of substantially completely filling elongated channels with foam, such as the channels in an extruded lineal used by the window industry. The method includes first orienting the channel in an upwardly angled orientation preferably greater than 30 degrees and less than 90 degrees, with a preferred angle of about 60 degrees. Where the channel has open ends, the lower end may be temporarily sealed. A thin, relatively high-pressure high-velocity stream of liquid foamable resin is then directed into the elongated channel open end generally parallel to the inside walls, such that the high-pressure liquid stream is carried at least partially down the length of the elongated channel, prior to contacting the channel inside walls and creaming. The liquid foamable resin then rises upwardly through the elongated channel, substantially completely filling the channel with resin foam.