Use the extended method when the original urethane adhesive bead left on the window opening pinchweld flange (after window removal) cannot serve as a base for the new window, or in any case where the use of the short method is in doubt.
This method includes the following cases:
| • | The replacement of a majority of the urethane adhesive bead, where a thin film of the original bead remains | 
| • | Applying pinchweld primer to any exposed painted areas on the pinchweld flange | 
No mounds or loose pieces of urethane adhesive should remain on the pinchweld flange. Do not remove all traces of urethane adhesive.
Important: 
   •  If corrosion of the pinchweld flange is present, or if sheet metal
repairs or replacements are required, refinish the pinchweld flange in order
       to present a clean, primer-only surface.    •  If paint repairs are required, mask the flange bonding area (prior
to applying the color coat) in order to provide a clean, primer-only surface.    •  Appropriate materials for these primer applications are typically
2 component catalyzed products. Use materials such as BASF DE17®,
   DuPont 2610®, Sherwin-Williams PSE 4600 and NP70®
   and Martin-Semour 5120 and 5130®. Follow the manufacturer's
  directions for the mix,  the application,    and the drying times.    •  After repairing the opening as indicated, shake the pinchweld
primer (black #3) well. Using a new dauber, apply the primer to the
     primed  surface of   the flange in the bonding area. Allow the primer
 to   dry for  10 minutes.    •  Use the extended method of replacement and the appropriate urethane
bead size when installing the window.