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ItsKYRO
09-08-2019, 10:50 AM
First time doing headlights. Used 400/600/2000 grit sandpaper followed by alcohol rub followed by clear coat.

Left side is what i did right side is untouched. Its a beat up headlight from a junkyard but still i expected to get nearly new results. Any thoughts to why i didnt get better results?


Imgur: The magic of the Internet (https://m.imgur.com/a/OGVGMmb)

Buster906
09-08-2019, 10:55 AM
First time doing headlights. Used 400/600/2000 grit sandpaper followed by alcohol rub followed by clear coat.

Left side is what i did right side is untouched. Its a beat up headlight from a junkyard but still i expected to get nearly new results. Any thoughts to why i didnt get better results?


Imgur: The magic of the Internet (https://m.imgur.com/a/OGVGMmb)What products did you use such as a headlight restoration kit? Did you watch any YouTube videos?

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ItsKYRO
09-08-2019, 11:16 AM
Used 3m wetordry sandpaper did all the sanding with water. Did swirl then horizontal on all 3 grits. Then used alcohol to clear off everything then did 2 coats of clear coat.

Paul A.
09-08-2019, 11:32 AM
I always compound and then buff with my rotary and 2" pads after wetsanding to final polish before respraying with clear. What you had was 2000 haze under clear coat.

Buster906
09-08-2019, 11:33 AM
Used 3m wetordry sandpaper did all the sanding with water. Did swirl then horizontal on all 3 grits. Then used alcohol to clear off everything then did 2 coats of clear coat.When I restored my headlights, I used my 3in GG DA and the 3M kit

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ItsKYRO
09-08-2019, 11:35 AM
I always compound and then buff with my rotary and 2" pads after wetsanding to final polish before respraying with clear. What you had was 2000 haze under clear coat.

Thanks for the response. I'm pretty new to this, what does the compound and buff do? Do you recommend products?

Paul A.
09-08-2019, 11:37 AM
I always compound and then buff after wetsanding to final polish before respraying with clear. What you had was 2000 haze under clear coat.

You're almost there. Maybe 3000 wetsand then machine finish...then, if you're happy with those results, clear again.

SWETM
09-09-2019, 02:35 PM
I always compound and then buff after wetsanding to final polish before respraying with clear. What you had was 2000 haze under clear coat.

You're almost there. Maybe 3000 wetsand then machine finish...then, if you're happy with those results, clear again.

But should not the clearcoat fill in P2000 grit marks?

How many layers of clearcoat did you do?

And the jump from p600 to P2000 is quite big. If you do it by hand maybe p1000 and p1500 is needed to be done. Also where you sure about that you went through the old clearcoat layer in the first step sanding? Cause often these heavy defects is cracked through the clearcoat layer. And you are sanding until you get through it. Have you been through any paint before you notice it. And you can also notice it if you dry sanding it and go on until you get a very bright white residue instead of the slightly on the yellowing residue from the old clearcoat.

Also what kind of clearcoat are you useing? Is it 1k or 2k. Do you have the primer for polycarbonate. This is if you want to get it as durable as new. With clearcoat only you will see it starting to crack and even yellowing in some cases. You can get a year or 2 from it. But done properly with suited primer and 2k clearcoat you will be getting very long lasting results if the prep work is done thoroughly. Then it's hard to see but look if you see any signs of the headlight has started to oxidize on the inside of it. Sadly then it's not so much you can do. It's the quite extreme temperature differences that happens fast on headlights and also so you get a great bond for the clearcoat the primer for clear plastic is important to use. Also that you use a great clear clearcoat so it's very transparent so a high gloss one is used. Maybe visit a paintshop and ask what they have available.

A great tips if you just want to get a quick fix or you can get the oxidation off quickly. Is to do a polishing with a metall polish. Then it's much easier to be following up with the sanding. If you are going to be primer and clearcoat them use a metall polish without any protection in it. These is useally on the acidic ph level and is very effective to desolve the oxidation on the protection coating headlights has. I got almost 9 months with only useing a metall polish with it's protection in it on neglected headlights. That where not perfect but very clear and a huge aprovement. It sat outside 24/7 after this before showing signs of needed to be done again. I could have been maintaining them with another protection sooner and keep them nice that way. But this was a test on how long it would be lasting. Used a wool cutting pad on the DA mini polisher as a first step and then a light polishing foam pad to finishing with and the same metall polish on both steps. The metall polish is a domestic brand and I live in Sweden. But any metall polish and prefered to have one without the protection in it. Then paint or protect them .

Also when you are sanding. Try to do each grit in different directions. This way you will see if you have leveled down to the grit before. You want to see only the grits sanding marks you are sanding with. Then move up in grit and a new direction.

These is some tips that I know of. It's a little hard with products recommendation as I live in Sweden.

/ Tony

WristyManchego
09-10-2019, 06:47 PM
This particular result looks to be due to the clear material not being applied heavily enough.

Does the surface of the clear feel rough/dusty?

Colour/base and clear require different methods of painting. With a base coat you spray for coverage so building light coats 2-3 times is recommended for full coverage. Once the substrate is covered the base is complete.

Clear needs to be “flowed”. Consider for a minute a pair of reading glasses, the only reason you can see through them is because the material is solid and has been highly refined on both sides to produce the smoothest finish possible, reducing light distortion through the surface of the lens.

The same needs to be achieved with clear. If you do light coats, you’ll end up with a rough and uneven surface that will refract light in all directions causing a cloudy appearance. To achieve a smooth final surface, the material needs to be applied more heavily to form a shiny, wet surface.

The trick is in applying enough to “flow” but not so much that you get runs.

If you determine this being the cause, the remedy will be to sand back the clear to a smooth surface again, prep wipe and reapply a single, heavier wet coat of clear.

Consider looking up “flow coat” or “spraying clear” on YouTube for further clarity.

Whitewater25
09-10-2019, 08:44 PM
I finish mine with 3000 then 5000 grit wet sanded, then polish to clear. Look brand new.

TTQ B4U
09-10-2019, 09:13 PM
Used 3m wetordry sandpaper did all the sanding with water. Did swirl then horizontal on all 3 grits. Then used alcohol to clear off everything then did 2 coats of clear coat.

I would not use alcohol on any acrylic lights or parts. I also wouldn't use anything below 800 grit.

Paul A.
09-11-2019, 07:14 AM
I finish with at least 3000 and sometimes 5000. Depending on how hacked up they were to start with, I rarely go any lower than 600. I then use a compound like Menz HCC 400 or Sonax CutMax and cut down those final sanding marks and haze. I then use a final polish like Menz 3500/3800 or Sonax Perfect Finish and refine what's left to a super fine gloss. Then spray a 2K clear.

Typically, yes, clearcoat spray should serve to level out 2000 grit sanding haze but I've not been so lucky every time. I treat headlights like paint and refine it the best way I know before using 2K clear as my LSP. Like paint, I want it looking like glass before I lock it in.

I will sometimes spray my 2K clear and hit that with 5000 and buff again.