Art glass film coating damage?

[T.J.G]

Hi there, wonder if anyone has some advice please.

I had some AR UV 99% artglass (groglass) delivered recently. I cleaned the glass of course, however, there where quite a few gummy type specs that were hard to remove. The glass is now fitted over black mountboard. Of course black shows up everything, when I analyse the glass in the light, I can see some iridescent specs. I tried cleaning but the specs are still there. I’m wondering if I’ve damaged the film coating with the original cleaning? Any advice welcome.

Thanks Thomas

[David McCormack]

You may have damaged the coating but I would say most likely not

What did you use to clean the glass? I would try again with a soft micro fibre cloth and some good glass cleaner that you would use for spectacles or camera lenses. I use Opti-Bright from Wessex.

I know the sort of marks you mean, green and purple etc., as you say iridescent, but they will go when cleaned. What you are seeing is grease/dirt which is interfering with the optical effect of the coating causing the colours to show. That's as technical as I can be there but I'm sure that's what t is.

[T.J.G]

Thanks Oliver, I was getting a bit exasperated, loosing hope! I’m using Nilglass H3. I’ve over handled a couple of pieces I think, in and out the frame too much and managed to scratch the film slightly too! I’m not convinced with the glass cleaner I have!

[David McCormack]

Cleaning my coated filters for camera lenses is a nightmare at times and coated picture frame glass is no exception. I stopped stocking full sheets of coated glass in the end and got Wessex to cut it for me to size. The trick is to handle it as little as possible

I would definitely try a different cleaner, good luck

Cheers (Dave)!

[T.J.G]

Thank you, I see Zeiss do a lens cleaning spray for coated glass, I might try that as I can get it next day.

[David McCormack]

Sounds good