assembly of the containment plates 34 and 36 on the nozzle plate 18 and permit the containment plates to slide relative to the plate 18 in the longitudinal direction of the cavities 48 by tightening the nuts 60 the biasing force holding the containment plates upon the nozzle plate 18 may be adjusted the extensions 46 are each provided with an oblique surface 64 fig1 upon which is mounted a scraper blade 66 on the extension of plate 34 and a scraper blade 68 on the extension of plate 36 by means of threaded bolts 70 the scraper blades are provided with a sharp leading cutting edge 72 and are also provided with sharp lateral cutting edges 74 the cutting edges 74 of each scraper blade being in engagement and equidistant from the nozzle plate sides 20 as will be appreciated from fig2 it will also be appreciated that the width of the scraper blades 66 and 68 is substantially greater than the thickness of the containment plates 34 and 36 as will be noted from fig1 and 6 the scraper blade edges 72 are in alignment with the associated containment plate pane engaging edge 44 in use the nozzle 10 is mounted upon support structure not shown usually adjacent a horizontal conveyor table capable of horizontally supporting a multi pane assembly 76 prior to application of the sealant the multi pane assembly prior to sealing consist of a pair of flat glass panes 78 and 80 in superimposed relationship.