Cloudy headlights

[DennisCA]

Unless you spray it with UV resistant clear coat. Doing that though you have to stop sanding at 1000-1500 grit or the clear coat won't stick.

 

[daedalusminos]

Here's the Cerakote going on on that same Audi headlight above - you can see that you don't need to get it crystal clear (2500 grit I think) as the coating is refractive index matching. Still do need to remove all lacquer though.

 

[E T]

I hate those plastic lenses. Who ever thought that would be a good idea?
Every car manufacturer should go back to good old fashioned glass. Things were definitely better in the good old days.

 

[premmington]

I done loads of these to get cars thru MOT's

1. If you gonna lacquer - spray some WD40 on lense - if it looks good with just wet WD40 it will look good with lacquer (obviously you gotta get WD40 off before you spray lacquer).

2. Mostly I just use a foam backing pad with cutting compound to polish them up. Yeah it can be a once a year job - but nothing like reworking lacquered headlights.

I reckon I do one set a week in our workshop as an average.

I have tried everything - Tcut - 3m stuff - Ceracoat - expensive stuff in green bottle. Nothing speeds the job up to be honest.

 

[Craig-SM]

I’ve used a few different kits including 3M, Holts and Turtle Wax. They all gave the same results and none of them last even with UV sealants. Turtle Wax is definitely the quickest and easiest

 

[nickk]

This is after another 2 hours,wet and dry,80/180/240/400, then the supplied pads of 800/1000/1500/3000. Then abrasive polish on the supplied mop.It’s worse than the lamp that I haven’t started,can’t remember the most time consuming job with a worst outcome than before I started.

 

[daedalusminos]

Using those coarse grades was probably unnecessary and now you've created more work for yourself. I can see course scratches (probably the 80 grit) in there which need to come out. Use the 240 until all 80 and 180 scratches are out - cross hatching the area with a sharpie (5 diagonal lines each direction) will give a guide as to when to move on to the next grade. Cheap sandpaper wears out quickly so you'll end up using more - I wouldn't be surprised if the kit sandpaper has now had it unless you have unused sheets.

 

[Slowcoach]

Were you planning on lacquering them. As mr. prem said try some liquid on them to see if lacquering will help. I’d probably try panel wipe, maybe thinners to see if it’s worth coating them.

 

[RWD3M]

Refurbing headlights can be considered much like polishing paintwork. I've done a few sets of headlights and have only once had to resort to 240 wet or dry, and they were absolutely dreadful and had failed the MoT. You wouldn't normally use anything much coarser than perhaps 400 or 800 on paintwork so the same applies for perspex. With every grade continue until all evidence of the previous grade has gone.

I will add, untill the very final polish (usually after 3000 grit), they will still look opaque.

All of the above is based on nothing more than my own meandering experiences! (Gotta love Baz Luhrmann!)

 

[MetalMonkey]

80?

Where did that come from? 400 is about as coarse as I'd go, if they were really badly scratched, maybe a little coarser, but 80 is for sanding down welds!

 

[Domdom]

I just use decent 600 wet & dry like 3M used wet, then rattle can paint lacquer.

 

[BrokenBiker]

80?

Where did that come from? 400 is about as coarse as I'd go, if they were really badly scratched, maybe a little coarser, but 80 is for sanding down welds!

I'll start at 240 if they are bad...80 is akin to using a brick

 

[nickk]

Typo,started with 180 .

 

[RWD3M]

Typo,started with 180 .

Have you managed to make any progress @nickk ?

 

[nickk]

Given up,it’s too time consuming,7 hours! If it fails the test ,I’ll buy new or good s/h.

 

[harveyp6]

The tester I use has a mini polisher onhand and he'll give the lights a quick polish should they need that.

 

[DennisCA]

3000 grit is gonna look cloudy no matter how much you sand it, you need to go on to polishing with a foam pad after 3000.

 

[nickk]

3000 grit is gonna look cloudy no matter how much you sand it, you need to go on to polishing with a foam pad after 3000.

Yes ,that’s how I finished.