DIY - 12C Moldy Headlight Fix for less than 50.00
So I have officially completed this "DIY - 12C Moldy Headlight Fix for less than 50.00" twice, so now I'm officially the worlds foremost expert! OK, OK, that's a bit strong. At least I have a fair understanding of the process? Anyway, on to the How-To-Do-It part of the post....
If you own a 12C and you have swipe doors you either have already done this or you really-really need to do this. If you fall into the "need to" category then you are in for a treat because this is actually a pretty easy DIY that can be accomplished in one day. Make it a weekend project for a more leisurely pace.
Disclaimer - I'm sharing what has worked for me, and it's worked twice. I am not responsible if all does not go perfectly for you. I hope you find value in what I'm sharing, and if you do have success please share your experience with the community here on McLaren Life.
What you will need:
new - 1 very plush micro fiber tower 7.99
new - Meguiars PlastX plastic polish 8.99
new - 3M Headlight Restoration System (you only need the 3" foam pad piece) 22.00
new - Tube of black 100% silicone (not caulk) 4.99
new - (optional) 4 bags of Silica Gel desiccant moisture removal pouches
used - hand/cordless drill to spin the 3" foam pad
used - An assortment of flat tip screw drivers to pry the lenses apart
FYI - I bought these items NEW just for this task, because this was the BEST way to reduce the risk of dirt contamination that could have caused scratches inside the headlight lens. So DO NOT be tempted to use some old microfiber cloths or an old foam pad to save a few dollars, get news ones and make your life easier.
Step One - Remove the front bumper. (You can do this part for free, but I cheated because I'm a busy guy, so I paid my body shop buddy a hundred bucks to do that part for me). If your gonna do it yourself, first remove both front wheels, then unbolt the bumper top, bottom, and all around. Have a buddy around to help so you don't accidentally let it flip forward 90 degrees and scratch up that beautiful paint. Once the bumper is off you can now remove each headlight. you car will look like the orange one in the picture below. Be sure to take a picture or two with your smart phone because your friends will never believe you when tell them you did it yourself and who doesn't want to have cool bragging rights next time your having beers with the fellows?
Step Two - Pre-heat your wife's oven to 225 degrees and have a nice beer to relax as the oven warms up. You will need as many flat tip screw drivers as you can gather up, a nice number to have is at least 5. If you are a pro you can get by with just 1 or 2 but the more the better. Also get an old towel and lay it on the kitchen table so you don't scratch anything up as you work. Put one headlight at a time in the oven for 10 minutes exactly. don't mess that part up, (If you go longer I'm not sure exactly what happens... but my imagination tells me it ends in a big disappointment and a trip to ebay to find a new headlight). The heat will not hurt your headlight housing, but it will soften the black sticky stuff making it very easy to separate the upper and lower halves in Step Three.
Step Three - Using insulated pot-holders, remove the headlight and immediately pry the upper clear half off of the lower black half. Using one screw driver per little plastic tab, you can separate/pry open all the tabs simultaneously and then using one last screwdriver you can work you way around the entire housing and release/separate the two halves completely. If the headlight cools too much and the black sticky stuff gets cold then just pop the light back in the oven and repeat the process again. (TIP - if you have clear bra/stone chip protector film on your headlights just leave it on, it's tough and the trip thru the oven won't hurt it).
Step Four - repeat Step Three on the 2nd headlight.
Now its time to remove the ugly filthy scummy moldly looking stuff that has made its home inside your "billion-air doors" super cars headlight lenses!
Step Five - Apply the PlastX plastic polish to your foam pad mounted to your cordless drill. Using light pressure and medium speed to gently polish the entire inside of the lens. this step can be accomplished in less than 5 minutes per lens. Now use that brand new microfiber cloth to wipe off the excess polish and hold the lens up toward a light to inspect your work. Repeat the polishing as many times as needed until you are satisfied with the result. Once you are satisfied, be sure to clean out all the polishing compound (especially in the corners) before you reassemble both halves of the headlights.
Step Six - Stack the top lens on the black bottom headlight half and return them both to the oven for 10 minutes. Now that the black sticky stuff is soft again you can "press" both halves together and reattach all those little clips around the perimeter of the headlight housing.
Step Seven - Repeat step six for the 2nd headlight
(optional) - Once the headlight has been reassembled and has cooled down, insert one or two bags of silica Gel inside to create a super dry internal environment and to help prevent a repeat of the problem ever again.
Last step - You have to ask yourself, why did my headlights get all moldy in the first place? The answer is they were poorly sealed by the manufacturer. Our last step is to improve upon the original sealing by adding an extra layer of the black Silicone sealant all around the exterior where the two haves come together. Additionally my buddy Thad over at Hypercar development suggested the electrical plug connector is an entry point for moisture so please inspect yours and apply silicone as needed to prevent any water intrusion there as well.
If all went well you can now re-install both headlights, reattach your front bumper, bolt up those front wheels and take a victory lap around your neighborhood to show off those brand new looking headlights.
Job well done!
- 2012 McLaren MP4-12C
- 2007 Mercedes S600 Designo
Last edited by ima2nr; 02-17-2017 at 10:02 PM.