1968-72 GM A body defroster duct tab repair

thingiverse

This is a repair tab you can revit and glue on to replace the often broken retaining tabs on 1968-72 GM A-body defroster ducts. Must be printed in PETG or another filament with reasonably high temperature resistance. PLA will not work, it will soften up too much in the heat/sunshine. I'd suggest both gluing and riveting it in place, you'll have to put an appropriate washer on the back side of the rivet or it will just crack the old plastic of the duct when you expand it. Print with the tab that has the rectangular hole facing down to the bed to get the layers to lay down in a way that won't break, sounds counter-intuitive .. but that's the way that works best for strength.