INON UFL-G140 removal/reduction of a scratch

Nando Diver · September 30

AOI customer support reply the following

Quote

For AOI UWL-03 lens, the front dome element is in polycarbonate with hard coating. If you polish the dome lens, the front hard coating will be damaged.

Best Regards,

Stephen Wu

Dave_Hicks · September 30

Quote

AOI customer support reply the following

Quote

For AOI UWL-03 lens, the front dome element is in polycarbonate with hard coating. If you polish the dome lens, the front hard coating will be damaged.

Best Regards,

Stephen Wu

Too late, it's already damaged! You have nothing to lose by sanding & polishing this dome port.

Davide DB · September 30

2 hours ago, Nando Diver said:

AOI customer support reply the following

Yes, we already know this from the previous posts.

But as David wrote. It's too late and you already have another one. So why don't try?

Elvandar · October 2

And you also already bough the Novus kit! Polish it for science!

Nando Diver · October 3

On 10/2/2024 at 9:56 AM, Elvandar said:

And you also already bough the Novus kit! Polish it for science!

ok...heres the science results.

This scratch is little deep, if you pass the nail you can fell it.

Novus 1 - didn't do anything

Novus 2 - didn't do anything

Novus 3 - i start with very light pressure, 10 minutes later i start to apply more pressure but the sctrach was not going way and i could feel it if i use the nail.

i was thinking, if there's a harding coating to protect the lens/dome, the amount of pressure necessary to scratch the hard coating was heavy, so to remove it i also need to put more pressure to remove it.

After polishing for about 15m, i stop felling the stratch with my nail, the scratch is gone, but now there's shadow/mark (like buble mark ) now remains in the lens, i suppose ive pass the hard coating surface and reach the lens surface.

I notice also, now there's more light shadow/marks (buble mark) around the old scratch area, if i continue to polishing, think more marks will come up...

The Marks on the lent are VISIBLE ???

Pictures No

Video YES

image Screen shot of the video Yes

Sink underwater test Inconclusive

Its better than before Inconclusive

it might be possible that the water fill that imperfections on the lens.

Im going to dive this weekend and let you know..

https://drive.google.com/drive/folders/1aOsE9gbn9uVWNXV6mEsSgXFGBwrfJK72?usp=share_link

Edited October 3 by Nando Diver

Elvandar · October 3

Really good try, but in your comment you said that you used the number 1, then 2 and last number 3, but in the video I saw, usually for deeper scratch they start from numer 3, and go down to 2 and 1 to finish the polish, you did not mention this passage, did you do it, and did not write it in the comment?

Here a good guide on it, even if I am not sure 10/20 second can remove the scratch, it's probably more in line with your timing, if you don't use a dremel or similar.

Let me know, I am really curious, since I also have the swapped lens, and if this method works, and I am unlucky enough to scratch it again, I could try the polish way.

Nando Diver · October 3

I start by 1 and 2 because it was less abrasive, and i didn’t want to damage the hard coat.

1 is liquid

2 mix of solid liquid

3 more solid

Polished with number 3 removed the scratch, but unfortunately was deep enough that was under the hard coating.

if I had start by number 3, the number 2 and 1 they don’t restored the damage to the hard coating already done.

Edited October 3 by Nando Diver

Davide DB · October 3

Given that, unfortunately during the years, I had to polish with Novus several polycarbonate domes of all brands and size, I'll try resume the steps.

Novus is the lightest polish product out there, so while removing a scratch requires a lot of elbow grease, the slow process makes it difficult to do damage.

The correct sequence is 3 > 2 > (optional) 1. Always.

Number 3 l: basically it's the real polish and even the lightest scratch requires a lot of work.
Number 2: it is the finishing cream. After passing No. 2 you're done.
Number 1: It doesn't do anything, fondamentally it's a simple glass cleaner.

If the scratch after #2 is still there. Start again with #3.

It is important to use a different cloth for each number and rinse the worked piece after each step.

Some cautions: always work on a much larger part of the scratch. If you insist only on the scratch you risk creating a pit, or rather a different curvature, which creates distortions.

All my domes had an inner coating. An external coating on a plastic (hence prone to scratches) dome is beyond me but that's it, both Inon and AOI have this design!

IMHO I would have sanded the whole lens.

Anyway, for an average scratch, working by hand, it really takes a lot of time and patience. Deep scratches don't go away but you can round the edges and make them invisible in water. Then there are the ones you can't do anything.

I would be curious to try it with a Dremel and a soft pad but then I never buy it. Every time I do the hard work by hand, I tell myself it will be the last time I scratch the dome.

Nando Diver · October 3

5 hours ago, Elvandar said:

Really good try, but in your comment you said that you used the number 1, then 2 and last number 3, but in the video I saw, usually for deeper scratch they start from numer 3, and go down to 2 and 1 to finish the polish, you did not mention this passage, did you do it, and did not write it in the comment?

Here a good guide on it, even if I am not sure 10/20 second can remove the scratch, it's probably more in line with your timing, if you don't use a dremel or similar.

Let me know, I am really curious, since I also have the swapped lens, and if this method works, and I am unlucky enough to scratch it again, I could try the polish way.

I saw that guy video before i polish the lens.

Ive start 1 & 2 in hope i didn't have use the number 3

Ive made 4 videos (named AOI old VS AOI new ) comparison between Old Lens and new lens in the Fish tank ... it looks promising, the water seems to fill that small gap/imperfections, but the real test will be at sea.

https://drive.google.com/drive/folders/1aOsE9gbn9uVWNXV6mEsSgXFGBwrfJK72?usp=share_link

here a video before being polished, once you see the scratch, you can't unseen.

ps: the video is 4K 60FPS, but for some reason google drive convert it to 1080p

https://drive.google.com/file/d/1XgatPbrhy64WaK2ISPDibCEVLGnHnpZ4/view?usp=share_link

Edited October 3 by Nando Diver

Nando Diver · October 4

in this print of the video AOI OLD , its possible to see the imperfections on the polished lens, but has soon enters the water, the marks gone.

Elvandar · October 4

So the polishing works, at least for the underwater footage!
Good to know!
But I still did not understand if you used the polish number 2 after the number 3 or you skipped the passage because it was good enough for you and you did not want to risk more

Nando Diver · October 4

3 hours ago, Elvandar said:

So the polishing works, at least for the underwater footage!
Good to know!
But I still did not understand if you used the polish number 2 after the number 3 or you skipped the passage because it was good enough for you and you did not want to risk more

Ive used 1, 2, 3....and when couldn't feel the scratch, ive used 2, 1.

I also Washed the lens with warm water when i jump from 3 to 2.

Number 1 & 2 are unable to remove the deep scratch., at least in my situation.

If i could do it again, i would use 1 & 2 polishing, and make an underwater test video, this way i would not touch the hard coating.

Nando Diver · October 5

Hi..

Ive put the polished lens to the test at sea and it's 99.9 perfect, better than having the scratch.

Now i can use the polish lens again, and in my case the green water helps hiding the imperfection.

Without certainty i believe that in Red sea, Porto Santo, Okinawa, shallow cristalin water with lots of natural light in certain conditions if you look for the artefact you can spot the imperfection, this dive i have about 20 clips and was very difficult to spot the issue.

the images below are the worst ive manage to spot...