polishing on plastic

[Daniel3507]

i was washing my moms car today and noticed some parts of it are a plastic. i was going to use her car to learn how to use a PC. do you do anything different when polishing on plastic surfaces? just waning to know in advance so i dont screw it up too bad.

 

[scary bill]

Don't let them get hot. Keep the buffer moving, don't let the pad sit on one spot too long.



Plastics and fiberglass do not react well with heat, they are insulating materials were metals act as a heat sink. If the paint gets too hot it can wrinkle up or burn off of the surface.



Don't polish on any plastic trim; flat black, or textured. It can really destroy it. Tape off stuff you don't want buffed with painters masking tape. 1 oz prevention beats a 1 lbs of cure.

 

[Daniel3507]

now plastic trim includes the black plastic in between the front and back windows of the cars? im not real sure what that is actually called but i have been wondering what you would do to that since i have seen some that look painted but are pretty oxidized.

 

[Accumulator]

Don't let them get hot. Keep the buffer moving, don't let the pad sit on one spot too long...

Very good advice :xyxthumbs

Don't polish on any plastic trim; flat black, or textured. It can really destroy it. Tape off stuff you don't want buffed with painters masking tape. 1 oz prevention beats a 1 lbs of cure.

Not quite as good advice Well, that's just IMO/IME.



Gotta be careful and you can't overgeneralize. I polish black plastic exterior trim all the time with zero problems. At least zero problems in the sense that I've been able to fix all my "oops!"es.



Repeating that "gotta be careful"



Some polishes are simply awful for this and others work fine 99% of the time. 1% of the time it's just a bad idea and for those you'd better stick with AIOs (and I'd be very careful with ZAIO, guess how I know).



How to tell if you have one of those 1% situations? Usually you try other stuff and mess up a (hopefully very small) test spot.

now plastic trim includes the black plastic in between the front and back windows of the cars? im not real sure what that is actually called but i have been wondering what you would do to that since i have seen some that look painted but are pretty oxidized.

Those are called the "B" pillars. I almost *always* polish them with the same polishes I use for paint. Which polish depends on the individual vehicle.

 

[scary bill]

"Gotta be careful and you can't overgeneralize."



I guess you got me on this. IME, though, the plastic trim on cars gets stained up by abrasive polishes. My lightning has some permanent stains where something I used got on the plastic. I have tried for 3 years to get it clean. Smooth plastic should be fine, I have the textured trim. It can make a headache for you fast.



So, to amend my statement * You should tape off anything you don't want polished.*



I don't really know why you would really want to "polish" that kind of trim except an AIO? Maybe you just have better plastic than me.



I hope I don't come off all :argue, as I don't try to.

 

[Daniel3507]

really i was more worried about the front and back bumpers and not the actual trim. i was washing the car and noticed that back bumper in particular is a very flexible plastic and just wasnt sure the best way to polish that. i dont really plan on doing any of the trim with a polisher just yet.



on a side note scary bill, do you have an 03 or 04 lightning? ive been on the hunt for a lightning for many years.

 

[Accumulator]

"Gotta be careful and you can't overgeneralize."



I guess you got me on this...

Well, it's a "YMMV" sort of thing and when it goes wrong you can get real issues like what you have on your Lightning.



A big part of it is using the right polishes; 1z stuff seems to work unusually well and so did the old 3M PI-III stuff as long as you buffed it off while still wet but that "while still wet" part was very important and could be a little tricky; OK on smooth trim but a PIA on textures.

IME, though, the plastic trim on cars gets stained up by abrasive polishes. My lightning has some permanent stains where something I used got on the plastic. I have tried for 3 years to get it clean. Smooth plastic should be fine, I have the textured trim. It can make a headache for you fast.

I had textured trim on the Blazer (and on my current Yukon) and I polish it just fine. BUT yeah, sure don't want an ongoing "oops!".

So, to amend my statement * You should tape off anything you don't want polished.*

Yeah, absolutely! :xyxthumbs

I don't really know why you would really want to "polish" that kind of trim except an AIO? Maybe you just have better plastic than me.

I had scratches and significant oxidation to deal with. My AIOs weren't cutting it so I used the polish with good results.



Don't use M205 for this though! (as with the ZAIO, gee...guess how I know )



I've used this approach on so many plastics on so many different cars that IMO it's not that mine are *better* plastics, just *different* ones, and I might be using significantly different polishes too.

I hope I don't come off all :argue, as I don't try to.

No, no...no worries at all! I too always wonder if my "hey, my experience was different" posts come off all :argue That's the last thing I want.



It's easy for me to get all revved up about this particular topic as my outside-the-box experiences have worked out so well for me, and I bet you feel the same way (in the opposite direction) given the issue on your Lightning.



With the two of us giving opinions from each side of the fence people can think it over and decide which way to go.



Now I'm wracking my brain trying to come up with what I'd to to correct your trim staining :think:



Off hand, I'd try 1Z Paint Polish, wiping off while still wet but I sure wouldn't run out and buy a can just to try it.

 

[scary bill]

On the trim I have tried at least a dozen different things to get the white stain to go away. I tried straight KAIO, IPA (somewhere around 95-99%), some mild solvent, wax blaster, back to black, Wizards forever black, tire gel, AA tire foam, and there is probably some I can't think of right now.





Some of the stuff makes it look good for a few weeks/washes. Some stuff looks better until it dries. The stains always come back, though.



I can't even remember what I got on the trim, as I haven't gotten such bad staining on any of the other cars I have done. The likely culprit is probably M09 or some cheap 3m rubbing compound. The staining didn't show up right away either, it took at least a few days to show.



It is hard to notice for normal people, but its just one of those OCD things. *I* know its messed up, even if the rest of the world doesn't see it.