How much spray paint to do a rear bumper?

[garycat]

I have acquired a rear bumper off ebay to replace one on a '03 Ford Fusion but it has lots of small scratches and areas that need a respray.

So, how much spray paint would be required to do a complete bumper? Would it need primer or could I just rub down the existing surface with a scotchpad to provide a key?

[ohtari]

I've never had to do a whole bumper, so I can't give you an exact amount, but it's more than you would think.

Regarding the primer, it won't be needed unless you sand through to bare plastic or have to use fillers. Like you say, just key the surface and you'll be fine.