I have a big thread and I am getting no where, so I’m going to make a few mini threads each its own point.

The photo below is the trunk of a 1991 Honda accord. Are these seams welded, or glued? I was reading some manufactures glued them up to help with flexing.

I have limited tools in welding (without buying) (homemade spot welder), after cutting out or grinding out rust I was thinking, fiberglass cloth or using strips 0.25 steel flat bar or strips of sheet metal spot weld in then fiberglass. Just need to know if it needs to flex.

photo 1 the okay side with glue / seam sealer
photo 2 the bad side that i pulled up the seam sealer
photo 3 some clean up