Originally Posted by Old Fool
Just curious if that would have been a good application for panel adhesive?
That would be an excellent place to use glue or body panel adhesive, the difficult thing about using adhesive in an area like this is the ability to clamp or put pressure on the replacement panel after you have applied the glue. You don't need a thick layer of adhesive for it to solidly bond and is best if you have a thin layer between panels. I often apply the adhesive, put the replacement panel in place, and in a case such as this, using bottle jacks from the bottom with 2 X 4's going from jack to jack to evenly distribute the weight and on the top side I use sheet metal screws on the corners and just to be safe, also for an application such as this I would lay something fairly heavy on top of the replacement trunk panel, like a piece of plywood with some additional weight on top of the plywood like weights from a weight bench, (I know it's improvising, but whatever works). Allow the adhesive to cure the required amount of time, remove the jacks, weights and sheet metal screws. Give the adhesive more time to cure (if the manufacturer says the adhesive has a 2 hour cure time, I like to give it 3, that way you know it's set up completely, cure times, depending on which adhesive you choose can be from as little as 1 minute to some that take 6, to 8 hours), weld up your screw holes and finish your repair.
3M makes excellent body panel adhesives, as does Norton and a host of other companies. There is nothing wrong with welding in a repair panel as "swvalcon" has done, in fact it's an excellent way to repair a rotted out trunk but, I wouldn't be afraid to use adhesive in these types of situations, both methods work very well.