I have a 87 camaro the front bumper has been 3 full time (primer, sealer base, clear 3 different paint jobs) I have some very serious web spieder cracking allover the bumper I have sanded all the way to the raw plastic bumper and I can still see the cracking and webbing.... Today I went to the paint store and bought a few things
1 sem ready to sray flexible primer surfacer
2 bulldog adhesion promoter...
3 DuPont flex additive

My plan is to strip entire bumper ground effect ect...(used 80 grit and a da) To bare plastic
Clean and prep then use the bulldog adhesion promoter then the sem flex primer then base then clear using flex additive....

Is that too much can the job to done with less steps and less product... Or am I wasting my time doing all of the cause the crack are just going to come right back

 

The paint will eventually crack if the bumper continues to flex. Having 3 paint jobs only added to the problem. You're on the right track with the plan you chose. I did my last two cars without any flex agent, but did them with the bumpers still in place. No cracking issues in the time that I had them..I did sand it all down though. From what I've heard (and this is debatable)...the flex agent is really only needed if the parts are done off of the car and will be moved around some. I.E...fitted/aligned, which should have been done before paint anyway.