PDA

View Full Version : Buffing Bumpers?



mr.ikon
08-28-2006, 11:27 PM
A detailer at the toyota dealership told me that bumpers should not be buffed. Claiming that the paint will fail and fall off? Is he full of it? I just thought i come here and ask for real advice. Thanks

Driven-528e
08-29-2006, 11:38 AM
Since bumpers these days are made of plastic, he is correct. mostly. Plastic doesnt distribute heat as well as the metal panels, and it is extremely easy to burn the paint off using a *rotary*. In fact, I`ve done it a couple of times (and certainly learned a lesson!). It can happen extremely fast. The dealership detailer would certainly be using a rotary. With a PC, its a different story. A PC doesnt produce anywhere near the same amount of heat and it would be difficult to burn the paint with it. However, given that you are working on a plastic bumper, be a little more cautious and aware when compounding and polishing them. When I detail a car I usually use a rotary on the metal panels and switch to a PC for the bumpers. Hope that helps.

mr.ikon
08-29-2006, 11:39 AM
anyone? someone has to know the answer to this.

TortoiseAWD
08-29-2006, 12:42 PM
It`s not so much that bumpers shouldn`t be buffed, just that you need to be aware that you`re dealing with paint that`s likely to be softer than it is on the body panels, and that you need to be less aggressive (lighter polish, softer pads, PC/Cyclo rather than rotary, etc.).



Tort

jmsc
08-29-2006, 12:47 PM
agree with what driven-528e says.



from experience, be very cognizant around bumpers (newer cars), rounded sheet metal panels, door jams. They just seem to have fragile or less paint there.

David Fermani
08-29-2006, 12:59 PM
Where are you people getting your information??? It is totally safe to wet-sand, buff and/or wax a painted bumper by a TRAINED, EXPERIENCED TECHNICIAN. If you don`t know what you`re doing stay away from it as well as the rest of the car. I worked on 1000`s of painted bumpers without 1 problem. Flex agents allow paints to be more flexable during a light impact or temperature change. They don`t make the paint more fragile, they make them stronger.

TortoiseAWD
08-29-2006, 01:11 PM
Where are you people getting your information??? It is totally safe to wet-sand, buff and/or wax a painted bumper by a TRAINED, EXPERIENCED TECHNICIAN. If you don`t know what you`re doing stay away from it as well as the rest of the car. I worked on 1000`s of painted bumpers without 1 problem. Flex agents allow paints to be more flexable during a light impact or temperature change. They don`t make the paint more fragile, they make them stronger.




With all of their benefits, plastic body parts do have limitations and drawbacks. One of the issues that I have discovered over the years is that painted plastic body parts are easily stained and dulled. To understand why, I researched the process of painting plastic bumpers and how it differs from painting metal body panels.



I have long known that it`s necessary to add a "flex agent" to paint that will be applied to plastics. The flex agent allows the paint to move with the plastic part without cracking or delaminating. What I did not understand is how the flex agents work. It`s very interesting, and it explains why painted plastic parts are so susceptible to staining and dulling.



Paint flex agents cause the cured paint to be more porous. In essence, the flex agent makes the paint foam, creating microscopic pockets. These pockets allow the paint to remain spongy and flexible. Most of the pockets are deep in the layers of paint, but some float to the surface. The flex agent also causes the paint to remain soft. Paint on TPO parts resists chips very well, but it will dent (small pock marks) from road stones.



The porosity and softness afforded by the flex agent create a couple of challenges. First, the paint does not resist stains as well as paint without a flex agent. Second, the flex agent paint cannot be buffed or polished with anything more than the finest polish, or the finish will be ruined. Buffing does not increase the gloss on this paint as it does on a hard paint finish; it smears it.



Taken from this link: http://www.autopia-carcare.com/inf-paint-polish-clinic.html



Paint with flex-agent may be stronger with regards to chipping, and being able to flex with the body panel; however, the porous nature of the more flexible paint makes it softer, and therefore more fragile when you`re talking about buffing/polishing the paint surface.



Tort

"untrained"

David Fermani
08-29-2006, 01:41 PM
Being an insurance adjuster, we no longer pay shops for flex additives for the refinishing process. We were directly told by several paint manufacturers that the paint systems now don`t require flex to be used. Also, Tier 1 suppliers who refinish non metal(plastic) body parts for car manufacturers are not required to use flex agents either. Paintless Dent Repair is an example of how flexible paint is without the use of flex agents. PDR guys are able to work the metal much more now a days without the threat of breaking the paint.

autoprincess
08-29-2006, 01:43 PM
"Driven" is on the right track.



There are 3 things to consider to determine the validity to the detailers comment. Year, Model, and type of paint. We already know the make, "Toyota".



Depending if the bumpers have been repainted they more than likely have single stage paint. I am assuming you have a corrola or matrix. Either case has the same problem, single stage paint. The paint is very soft, thin, and stains easy. It does not take much for these bumpers to stain, and when they do if the stain is yellow or brownish in color there is not much you can do because they are sprayed very thin with paint. Like "Driven" said it does not take much to burn through them, especially around the edges and headlight area. If you have a corrolla or matrix and it has a ground affex (sp) package they are painted the same way and you will more than likely have the same problem in those areas. If you are sloppy with tire shine, the tire shine can stain these areas as well resulting in a yellowish/brown color.



So as far as your question of if allowed to buff my answer is yes it can be done, be it can very easily be burned through, I use a High Speed buffer and have no experience with the PC because I can work the High Speed good. I need the extra heat of the buff pad at times so it is ideal for me. When I buff those types of bumpers I do not spend a lot of time on them. You can wetsand them to some degree but that goes back to the problem of thin paint and the amount of time you can spend on it with a buffer.



So my advice, if you know how to use the buffer don`t spend a lot of time in one area and becareful of the edges, but just because you are buffing the area it does not mean that you will get out whatever you are trying to get out, because like I already said the paint is thin and it does not take much for the paint to stain to the point where only detailing can fix it. Or you can try the PC.



If you are not very experienced with the buffer, I would say not to attempt.



By the way your paint will NOT "fall off"

David Fermani
08-29-2006, 01:55 PM
"Driven" is on the right track.



There are 3 things to consider to determine the validity to the detailers comment. Year, Model, and type of paint. We already know the make, "Toyota".



Depending if the bumpers have been repainted they more than likely have single stage paint. I am assuming you have a corrola or matrix. Either case has the same problem, single stage paint. The paint is very soft, thin, and stains easy. It does not take much for these bumpers to stain, and when they do if the stain is yellow or brownish in color there is not much you can do because they are sprayed very thin with paint. Like "Driven" said it does not take much to burn through them, especially around the edges and headlight area. If you have a corrolla or matrix and it has a ground affex (sp) package they are painted the same way and you will more than likely have the same problem in those areas. If you are sloppy with tire shine, the tire shine can stain these areas as well resulting in a yellowish/brown color.



So as far as your question of if allowed to buff my answer is yes it can be done, be it can very easily be burned through, I use a High Speed buffer and have no experience with the PC because I can work the High Speed good. I need the extra heat of the buff pad at times so it is ideal for me. When I buff those types of bumpers I do not spend a lot of time on them. You can wetsand them to some degree but that goes back to the problem of thin paint and the amount of time you can spend on it with a buffer.



So my advice, if you know how to use the buffer don`t spend a lot of time in one area and becareful of the edges, but just because you are buffing the area it does not mean that you will get out whatever you are trying to get out, because like I already said the paint is thin and it does not take much for the paint to stain to the point where only detailing can fix it. Or you can try the PC.



If you are not very experienced with the buffer, I would say not to attempt.



By the way your paint will NOT "fall off"



Toyota(as well as other manufacturers) has been using 2 stage paint on their bumpers for over a decade. Unless the toyota dealer is doing recon on older vehicles, I don`t think he`ll run into a problem.

imported_Grouse
08-29-2006, 01:56 PM
tag wonderfull info