Painted bumper correction?

[Dave's Detailing]

I used a PC on an old Ford Fusion that needed some deeper cleaning then I could manage by hand. There was some slight paint cracking on the bumper that seemed to get worse after I used the PC.

My question is, once I saw the cracking, should I have backed off the PC and only worked by hand? I assume the vibration of the machine caused the cracking.

Generally speaking, it's ok to use the machine on a painted bumper-plastic or fiberglass?

[dave_from_here]

Re: Painted bumper correction?

My question is, once I saw the cracking, should I have backed off the PC and only worked by hand? I assume the vibration of the machine caused the cracking.

Generally speaking, it's ok to use the machine on a painted bumper-plastic or fiberglass?

paint usually cracks because it is dry, overheatd or not stycking to the surface. I doubt that your PC would induce that kind of damage. If the car is old it's more likely that the paint was never maintained and it cracked because it was way too dry, sun burnt etc...

Whenever you see damage appearing on the paint, it is a rule of thumbs to stop whatever you are doing and reassess the situation.

I have always used machines to correct paint on bumpers (rotaries). But always be carefull and set the speed at the lowest and take your time.

[Murr1525]

Re: Painted bumper correction?

Just the pad spinning and the pressure can make the cracks widen, spread, etc. Since they are not fixable, just working gently by hand would have been best.

[dave_from_here]

Re: Painted bumper correction?

Just the pad spinning and the pressure can make the cracks widen, spread, etc. Since they are not fixable, just working gently by hand would have been best.

I agree

[jfelbab]

Re: Painted bumper correction?

The paint used on modern bumpers is not the exactly the same as that used on the rest of the car. It contains more flex agents to be less brittle and less prone to cracking. Bumpers do need to hold the paint and handle slight bumps without cracking.

These bumpers are plastic covers and they don't dissipate heat well. Using a polisher, even a DA, could cause excessive heat depending on the pressure and product used. I always use light polish and pressure along with faster movement on bumpers to avoid possible damage.

[J. A. Michaels]

Re: Painted bumper correction?

Just the pad spinning and the pressure can make the cracks widen, spread, etc. Since they are not fixable, just working gently by hand would have been best.

This would have been the prudent way to proceed.

[Michael Stoops]

Re: Painted bumper correction?

An "old Ford Fusion"?? Ford only introduced this model in 2006!! Man, wait till the guys with '70 'Cudas, '67 Camaros or '57 Chevys get wind of this!!

All kidding aside, do you have any idea how the cracks came to be in the first place? Any indication of contact with the panel? As jfelbab pointed out, the flex agent in the paint on the bumper covers should have allowed the paint to be resilient enough to handle some major flexing/bending of the panel. There is a possibility that the paint was not only cracking but also just starting to lift at the point of the cracks. If so, then even aggressive hand application of a product might worsen the situation. Whenever you're dealing with compromised paint, especially when it's cracking, peeling or even just really thin, you almost can't be too cautious.