I want to smooth over the strip in my bumper, I have used bumper filler on things before but it always seems to crack, could I not just use normal filler??

 

The problem with fillers is the plastic of the bumper is flexible, it moves with heat, the car moving and people bumping into it. Filler does not do any of these things as it sets quite hard and therefore is not flexible. If it must be done it might be worth hevily scoring the plastic in and around the recess and fibreglassing it into and across the joint, then use a filler. The fibreglass may hold it stiff enough to protect the filler.
Otherwise get it to a bumper bar repairer who may be able to weld plastic into the recess and form a uniform material across the strip.

Cheers,

Justin P

 

i smoothed both bumpers on my car.
you have to make sure the inside of the swage line is really well keyed up, say with 80 grit paper,then fill the swage line with fibreglass to build it up until its almost flush, then for the final skim use a thin layer of filler

couple of pix of my bumpers

 

Thanks guys, that Fez looks ace.