Abstract: Relates to a flux dam for submerged arc vertical position welding. The dam comprises a sheet of high temperature stable non-metallic material, a permanent magnet aligned with a first pole thereof substantially at a first surface of the sheet for magnetically attaching the sheet to a vertical workpiece generally parallel to and spaced by the thickness of the workpiece from a generally horizontal weld area of the vertical workpiece to an abutting horizontal workpiece, the magnet extending generally towards a second surface of the sheet, the magnet being affixed in the aforementioned alignment thereof. Also relates to an improvement in a welding method using said dam.