A method of making at least partially foam-filled sandwich panels includes providing a panel shell, moving at least one of a portion of a first and/or second panel facer or a side member away from the panel volume, thereby defining an opening between the volume and an exterior area. A dispenser proximate the opening moves across at least a portion of the opening while dispensing an amount of a foam agent into the volume through the opening. A press has three platens, a third platen of which is secured to at least one of a portion of the first and/or second facer and the at least one side member and is moveable with respect to the first platen and the second platen in response to a control system.