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chris0626
10-05-2003, 11:47 AM
Had a great chance to try out some products yesterday at the Autopians GTG, and I`ve made a couple of brief remarks, but wanted to do a more organized report.



The plastic headlight covers on my Benz are a sort of "ribbed" plastic. They were horribly yellowed (I think Forrest said "oxidized"), and had very deep scratches/pits. Also realized that some things I thought were scratches are actually cracks that go all the way thru the lens cover.



I had bought the 3-pack "trial kit" of Novus 1, 2, and 3, and planned to tackle the lens covers with those. But the general consensus was that even Novus 3 wasn`t aggressive enough.



Forrest shocked the heck outta me by handing me a jar of Mothers Mag & Aluminum Polish. :eek: (Turned out he knew what he was doing, of course! :D ) Under his guidance, I used the PC and Meguiars red pad. Slathered some Mag/Alum Polish on the lens cover, used the PC at a pretty slow speed (2-3). As Forrest warned me, 2 things to watch out for:

1. Don`t use much pressure, or you could (a) cause more cracking and/or (b) cause heat build-up which would (of course) be an awful thing on plastic.

2. Keep feeling the plastic as you work, to be sure it`s not getting warm.



Worked the polish a long time (maybe 5 mins?), stopping occasionally to wipe off, check results, then apply more polish and continue.



There was definite improvement in the "brightness" or clarity of the lens, the yellowness was virtually gone, and there was a dramatic improvement in the smoothness. So then I spritzed it with alcohol/water (not sure why, but Forrest told me to -- probably to clear off residue), and applied Mothers Plastic Polish. Mighty fine. So then I did the other lens using the same process.



Toward the end of the day, Mike demo`d Meguiar`s PlastX and explained it has diminishing abrasives, so I grabbed it out of his hand and ran back to the lenses. Used it on one of them. As he had warned, it took an awful lot of elbow grease, and I worked it a long time by hand. It further improved the "brightness" and further reduced the scratches/pits.



Not sure exactly what my conclusions are, and I`m not exactly great at the "scientific method." In future, if normal plastic polishes don`t do the trick, I expect I`ll repeat pretty much what I did yesterday -- going on the "start with least abrasive product" principle: start with Mother`s Mag/Aluminum polish, then move to the more aggressive PlastX. I think I can still get the lens covers smoother, so I expect to continue with the PlastX.



A caveat: Remember I was dealing with hard plastic (not something flexible like a convertible rear window), so I was able to use a fair bit of pressure with the PlastX.



Hope this is helpful to others.

forrest@mothers
10-06-2003, 08:16 PM
Originally posted by Lynn



So then I spritzed it with alcohol/water (not sure why, but Forrest told me to -- probably to clear off residue), and applied Mothers Plastic Polish. Mighty fine. So then I did the other lens using the same process.





Alcohol removes the coating that Mag and Aluminum polish leaves behind, so the plastic polish will work better. And, it`ll get the white residue out of the cracks in the plastic.

CRXSi90
10-06-2003, 11:13 PM
I used Meguiars Scratch X with my PC on my dad`s 1991 GMC truck which had very yellowed plastic headlights. They came out a lot clearer. Not perfect, but for the miles he has on the truck [over 300,000, not exactly sure], but a large improvement.



I broke both of forrest`s suggestions when I did this....I used a fair amount of pressure to get the "bite" and to build heat...the heat makes the plastic softer, and it was a very cold day. :) I understand the not using pressure part, but what is wrong with building heat? After all, these are headlight covers and they have strong, hot lights behind them. Feel the light after it has been on for a while...it is warm.



Kev

imported_Dave Holmes
10-06-2003, 11:17 PM
Lynn,



Saturday, I had bought a tub of Mother`s Mag and Aluminum Polish for my front strut tower brace. Worked wonders on it. I then remembered reading somewhere (can`t remember where), that it was good for hard plastic lenses. I used it by hand on my `97 Maxima`s headlights, which were slightly oxidized (yellowish). It worked great! The white cotton cloth I was using turned yellow. After wiping off, the lenses were crystal clear, and had a "shine" that plastic polishes haven`t been able to leave. I can only guess the addes shine is from the protection it is supposed to leave on the finish.

I really like the Novus #2 and 3 for their intended purposes, as they are very hard to beat. But for just a general cleaning, and final added touch, I think the Mother`s Mag on my lenses will become part of my routine.



Dave

chris0626
10-06-2003, 11:25 PM
I`m with ya, Dave! I never would have had the nerve to try a metal polish on plastic lenses if Forrest weren`t there, guiding me step by step. Glad to hear your confirmation!

forrest@mothers
10-07-2003, 06:52 AM
CRX - I always suggest folks not build too much heat because it can get away from them and cause more damage.



If the heat`s from pressure, any cracks present (and Lynn`s lenses - polycarbonate - had lots of them) could get worse.



If the heat`s from speed, using too much speed, too long, could overheat the plastic too much and cause it to fog.



I`m using the heat indicator to maintain safe limits.

MikeStang
10-07-2003, 01:52 PM
I used to have an 89 Ford Mustang 5.0 that had headlight lenses that were butter yellow. They looked horrible and also made the car look really old. I tried all of the compounds, polished, that Plexus stuff and none of them worked. So...I took off all of the lights and wet sanded them with 1500 grit sandpaper. It got all of the yellow/oxidation off within minutes. After that, I took my dad`s rotary with a wool pad and compounded the lenses to perfect clarity(to remove any marring from the wet sanding...). You might not want to try that on your car, but I had nothing to lose.

CRXSi90
10-07-2003, 06:10 PM
Thanks forrest, your reply makes sense. :)