Rick,
patch panels come in many forms.. Sometimes there are edges that are spotwelded in the original construction. These edges are usually secured with plug welds that act very similar to the original welds. For most of the other edges, butt welds usually employed and they are continuous. Sometimes on low crown panels, a flange is made and the panel is lapped on top of the flange. This arrangement lends itself to the use of adhesive, if desired.
