Headlight angst?

[ashber]

So I decided to have a go at cleaning my headlights on my 911 as they’d started yellowing around the edges with some blurs on the lens!
So after much reading and Youtube video watching I did some wet sanding starting with a course then fine grit and then after admiring the destruction of not my headlights I started polishing with my DA!
Which brought them up like new!
I then sprayed them with a clear acrylic spray, this is we’re it went wrong as the acrylic seemed to dry with creases in it! So lightly hand sanded it off again and re-polished!
They look amazing, but I can not see loads of what look like Tiny stress cracks!

Any ideas, I wonder if they were already there but can see them now because of how clean they are? But I think I would have noticed!

I have not ordered some Gtechniq to coat them!

[Itstony]

Can't see anything from that little pic.
Too little info, so guessing here. Sounds like you did ok and the spray job was too much causing the ripples??
When sanding down it doesn't take bundles of time, so stage it down and take it easy. Not any rules as each condition is different grit wise as long as it end up what you need.
For a usual one, go with 1500 grade and finish up on at least 2,500 grit. Right there you can see the lens condition. A nice consistent milky haze.
Quick polish and done.
For me personally, I won't go with any permanent or difficult to remove sealing. Can be more ag than necessary at time like now. Use wax if you want. I like JetSeal as it suits the job, with UV protection and ideally suited for easy maintenance.
The crazing may well be that sealant, so back to the beginning and check as you go

	Autoglym Autoglym - A UK based Manufacturer of car care products.

[ashber]

Having trouble with posting pics! Anyways, did end upon 1500 so all good! Was after polishing I could see the tiny cracks! Millions of them throughout the entire lens! I’ll look up the jet seal you mention!

See if this pictures better?

[Caledoniandream]

If you spray them with clear lacquer, you have to sand them to key for the lacquer.
Paint can not grip on a polished surface, also there will be a reaction with the polish unless complete degreased.
Remember any polishing, sanding, and painting can affect the pattern of your dipped beam, and causing problems with your next mot.

[Itstony]

Originally Posted by ashber

Having trouble with posting pics! Anyways, did end upon 1500 so all good! Was after polishing I could see the tiny cracks! Millions of them throughout the entire lens! I’ll look up the jet seal you mention!

See if this pictures better?

You must end on 2,500 grit minimum, I have all options to 7,000 grit but most I end with is 3,000 grit.
You must start with 1,500 grit.

[H-M3]

What specific brand of grit paper you using/recommend?
Cheers

[\Rian]

Did this recently on my Zaifra, Sanded with 1500 then 2500 then hit it with sonax profiline perfect finish and sealed with Gtechnique G5

[66Rob]

I can't tell from your picture but my Cayman has similar tiny looking stress marks just around the edges above the silver coloured ring. I am pretty sure that they are in the headlight as opposed to being removable yours may be the same.

[BaileyA3]

I have sanded and polished a fair few sets of headlights and all have turned out fine and looking like new again until recently. I did the headlights on my mk5 golf following the same method I have always used only this time I used a mini rotary (shinemate ep803) to polish them up (previously used a das6 pro with a 3 inch pad) and ended up with loads of the same little stress cracks you describe. I wondered if maybe I went too hard on them and the cracks may have been caused by heat build up using the rotary. I have another set to do soon so will take it a little easier on them and see how I get on.

[Itstony]

Originally Posted by BaileyA3

I have sanded and polished a fair few sets of headlights and all have turned out fine and looking like new again until recently. I did the headlights on my mk5 golf following the same method I have always used only this time I used a mini rotary (shinemate ep803) to polish them up (previously used a das6 pro with a 3 inch pad) and ended up with loads of the same little stress cracks you describe. I wondered if maybe I went too hard on them and the cracks may have been caused by heat build up using the rotary. I have another set to do soon so will take it a little easier on them and see how I get on.

Lubrication and heat is an issue. I find it helps and does no harm to have a water spray available, not just for the sanding, but the polishing too. Bit messy but no heat neat will be generated which is important.