An FYI for anyone who is going down this path in the future.
- Unless you need to change the colour of your headlights, don't split them open - once you get a mark on the inside of the lens it will be impossible to remove without professional equipment and experience. You may think that some of the degradation is on the inside of the lens, but it isn't.
- Remove the headlight assemblies from the car
- It is all well and good to use a headlight restoration kit, but it won't be good enough. You're better off buying a set of wet and dry papers off of ebay and using those. I started at 120grit as my lenses were so bad. I finished on 5000 grit. It took me about 8 hours per headlight.
- Resist the temptation to sand this with a machine, you'll eat through the soft plastic and severely regret it.
- A finishing automotive polish, or a superfine acrylic polish will remove the sanding marks. You will need a RO polisher, no exceptions.
I tried the polishes from three different products:
Mother's NuLens - Trash
Turtle Wax Headlight Restoration Kit - Pro, but the headlight sealant wasn't very good
Meguiars Two Step Headlight Restoration Kit - Good, the headlight sealant was pro. If you're going to do this, I'd pick this one.
6) Getting rid of the polishing marks in acrylic is impossible, a headlight sealant or clear coating the plastic is the only solution. I found Meguairs sealant the best as it was in a spray can. If you can find a good paint shop, getting them done in automotive clear would be a good solution - but there are issues with painting smooth plastics so take the body shops' advice.
If you have to open the headlight for any reason:
- Polish the lens to completion first, that way you will handle the lens as little as possible while it is off the assembly.
- You will absolutely chip the pain on the coloured insert, no exceptions. Be prepared to paint it when you're done.
- The chrome on the chrome rings will come off if you touch them. You need to remove them in order to repaint the insert. Be prepared to get them painted or rechromed.
I'm all about DIY, but I would honestly send this to a professional unless you've already messed around with paint and detailing a lot. It is one of the most difficult polishing jobs I've ever done. As it is, I could do better now that I've done it and I had the lenses apart for over a month testing different methods and polishes.