"Pop rivets are not structural. "
TRUE for the most part....

"A rivet job is a bandaid patch, not a repair, something to get you home so you can repair it."

Not true if done correctly.... just ask Boeing etc... entire planes are held together with rivets...

And most structural parts of FRAMES on old cars had rivets... Spring perches, transmission supports, the upper and lower A Frame mounts , etc.
All done with steel rivets.... typically 3/8ths thick stem.... and applied hot...

For rivets to be proper structurally one must do some studying ... for instance the relationship between the thickness of the sheet metal compared to the stem size of the rivet...and how close the rivets need to be placed.

The Eastwood Company catalog is great information ... there are spot riveting welders which only have to be on one side of the metal... as compared to the old days... and Aircraft tool supply is great reference....

http://www.aircraft-tool.com/