@
thook
I recently picked up my own used frame with obvious overspray on the left side chainstay. I watched a couple of YouTube videos about removing overspray without rubbing compound and BAM! I'm an expert on using a clay bar!
J/k but auto detailers use them to perfect the finish on show cars. The logic behind it is simple enough, and a few tutorials will help you learn too. I think the key is using a lubricant on the finish (like soapy water) , and using a clean section of clay to avoid dragging contaminants across the finish and scratching it up.
Overspray is essentially a paint job on an unprepared surface, so the overspray can't hold onto the top coat as well as the top coat holds onto a scuffed undercoat.