Molding Rear Bumper Questions Options

[DSToyo]

i am considering molding my rear bumper of my kit. i have never worked with fiberglass and wanted to know how hard it is and is it worth it. i have heard that the mold can crack when being tapped in the parking lot or even weaken with the canging weather conditions. i guess my question is, is it worth it when i am going to get a paintjob/how easy does it crack/how to repair if cracked?

Thanks for any feedback possible

[Kadett]

My painter doesn't mold bumper/spoilers/skirts etc etc because he can't give any garantees it will not crack. Because of vibrations in the roads and resonance it will crack, its just a matter of time, maybe a week or even maybe a year, but he has seen it happen alot. (his words)