Automotive Plastics: Crack in Bumper II, bumper repair, polypropylene


Question
Thanks for replying to my first question. You asked me to find out what kind of plastic that the 2006 Sebring rear bumper has. I don't have the knowledge to remove it, so after looking through the Internet I would guess it's >pp<.
Also I looked more closely at the "crack" and there is no depression or break. The surface paint is split so all I need to do is paint over the 8" long 'scratch'.
I don't want to pay for a professional paint job so I would like to sand it smooth (very little sanding needed) and paint over it.
How do I make it paintable and what should I use to paint it? Brush or spray?
Thanks again, Al

Answer
Ok Al, though the reparing conditions are not the best, let us try it this way:
materials:40 watts soldering iron (available at the dollar store), sharp blade to scrape the paint off at both sides of the crack, a grinder, or 80 grit sand paper and a 360 grit piece to finish the bondo outer coat, a piece of PP to fill the crack (from a similar or so marked bumper, a 1/2 an inch square piece of metal grill from a discarded speaker cover grill. (this is similar to the grill you have in your microwave oven door) this grill may be usable if the bumper material is thick enough to get that metal piece inserted.Primer (adhesion promoter), bondo (filler) paint, clear coat if applicable. and the smallest plastic cable tie. Do you think you are able to gather ALL THIS STUFF? if not let me know whether we can substitute one or two of them...