Polish on Plastics?

[Kn0x]

I always thought that was a no-no. Isn't that why the plastic trim is taped off?



But lately I have been seeing a lot of threads about people using their PC's with Polish on everything from headlights and taillights to side view mirrors with good results.



How can this be accomplished without wrecking the surface?

 

[kapinnn]

With a rotary, just don't stay in the same spot , reduce speed, use a light cut pad/polish. If using PC be careful about putting too much pressure while using 4" pads.

 

[Setec Astronomy]

What is taped off is usually rubber or textured plastic trim, which can be stained by polishes. Also some trim has blackout paint on it that can be easily damaged. Headlights and taillights are fine to polish, as well as painted plastic mirrors and other parts (sometimes you need to be careful about getting polish residue stuck in the molded-in words on some lenses). The thing to remember about non-metallic parts (this includes bumper coverings and lower valences/side skirts) is that plastic has MUCH lower thermal conductivity than metal, meaning that any heat that is generated from polishing will not dissipate from the area easily, so that you can unexpectedly build up heat between your pad and the panel...and melt your paint.

 

[kapinnn]

The thing to remember about non-metallic parts (this includes bumper coverings and lower valences/side skirts) is that plastic has MUCH lower thermal conductivity than metal, meaning that any heat that is generated from polishing will not dissipate from the area easily, so that you can unexpectedly build up heat between your pad and the panel...and melt your paint.

Tell me about it... I hit a lower panel of a lexus this weekend without knowing it was just a plastic molding. I wetsanded an area that was above the molding but the rotary hit the plastic a few times. Needless to say, It melt the paint, wrinkled, and scraped it. I'm getting the panel repainted for the customer. I still can't comprehend how nice the guy was about it and still gave me a tip...

 

[stuart hicks]

Wanna add to the warning. I got lazy when buffing my girlfriends honda and used the rotory to clean the bug splats on her headlight lens. The rotory made the lens cloudy in a few spots. Watch out for that too.