a method is disclosed for temporarily bonding reinforcing sheet metal pieces or other metal pieces to a sheet metal blank for forming at an elevated temperature such as is employed in superplastic forming of suitable aluminum , magnesium , stainless steel or titanium alloys or the like . the pieces are bonded to the blank in locations in which the piece will acquire a desired shape from co - formation with the blank . suitable water suspendible sodium silicate compositions , such as water glass bond the piece to the blank during high temperature forming and permit removal after forming .