Although the photos in this thread are not of my 040 Super White MR2 Spyder, the process and concerns I have should be the same, I would think. I took some time yesterday to try to buff-out the fog on the headlights of my wife's Prius V, as they were looking a bit fogged-over. Before Pictures:
I used an inexpensive Chicago Electric (Harbor Freight) 7" Rotary sander/buffer with a 3M foam polishing pad and Griots Correcting cream (polish). All went well as long as I kept the RPM at 1000 or 1500 -- when I got up to 2000 RPM there was greater likelihood of me melting the plastic, so I kept it below 2000 RPM (as identified on digital settings on the tool). The results were pretty good.
My wife was definitely pleased with the results. I noticed that although I could make the fog decrease -- almost seemed like it went away -- I was not able to get rid of all of the yellowing.
My questions to the community then are: 1) is it even possible to buff out the yellowing? Did I just not buff aggressively enough? Is there a different polishing compound I should use (i.e., Mother's Aluminum Wheel Polish)?
I did treat with 303 Areospace afterwards so hopefully that will prolong the clearness of the lenses. Thank you in advance for your wisdom, knowledge and input regarding the questions I have posted.
Oh, and by the way, this was a pretty easy maintenance job to do. If anyone out there is afraid of attempting this, it really is pretty easy. My only advise would be to keep the RPMs in the range I reported -- and keep the buffing pad moving around (not staying in one place on the lens) -- in order to keep from melting the plastic lenses. It may be that in the hands of a skilled craftsperson that the RPM range I used is not the preferred range, but for someone like me who really didn't know what I was doing, it seemed to work pretty good.
Excellent work. I also polish this way and it’s easy and quick. Better than the commercial products kits that use very aggressive sand paper. You probably could use something stronger like a light cutting compound. Another tip is to have a spray bottle with you to cool and lubricate the surface as you work it in so you don’t overheat the surface. The haze comes out easy but the yellow takes some time to get out. If you get to the point where the lens looks like glass and it’s still yellow it might just be baked in.
Also start slow and controlled. Speed comes with experience and results but also damage to the part and it can get dangerous if it slips out of your hands.
Good work! You took the most important step: sealing the headlight. Once the UV protective coating is gone, they yellow. Once you polish, thy'll yellow again unless sealed or protected. I've never used 303 Aerospace but Meguiar's has a special headlight sealant that's spray on that I was considering trying. Also never used it, but since my Spyder headlights are showing signs of degradation, it might be time to buff and clear.
Sadly there's really no way of getting the yellowing out in the headlight world. Even pro detailers don't do anything about it. I wonder if anyone has ever tried UV? Or hydrogen peroxide? I know a lot of retro console restorations have the horribly yellowed plastics thrown in a tub of hydrogen peroxide and bathe in UV light and it often goes back to perfectly clear, or gray, or whatever the original color is.
2000 Toyota MR2 Spyder, 2021 Lexus UX 250h F Sport
That was an interesting video to watch. Thanks for sharing. I learned a few new things from watching it, including there are UV LEDS?! That's a trip!
Fun fact! Most white LEDs are actually UV emitters under a coat of phosphor. The phosphor does the conversion from UV to visible light.
2000 Toyota MR2 Spyder, 2021 Lexus UX 250h F Sport
That is a fun fact!
http://zero3nine.com/files/dospwn.gif
Best headlight sealant I've used is Helmsman Spar Urethane. It's often used for boats so it has a high anti uv doping agent concentration compared to other products (or so I tell myself).
Cut it 50/50 with odorless mineral spirits and wipe it on with a folded up blue paper towel. Surface prep i've had the most success with is sanding to 1500 and wiping down with Isopropyl. I've had a few cars last 3 years before any hazing signs when done right. On my spyder, I sanded to too high a grit and had early flake off due to poor adhesion.
- When applying, dont go back over same spots, other than application overlap. It will self level as mineral spirits flash off. Going back over will potentially pull fibers off the towel because it becomes tacky fast
Edit 04/08/2020: just redid my lights, sanding to 1000 grit. Honestly, its kind of a pain to sand and coat but they last a few years like this. I think the prius headlights look pretty good from just a polish.