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Isopropanol destroyed coating

Started Feb 25, 2022 | Discussions
sssboa Junior Member • Posts: 32
Isopropanol destroyed coating
1

Hi,

So I had a ring of mist on the inside of the rear glass of a vintage meyer-optik lens from the 1960's or so.

I used isopropanol to remove it, it worked but also removed the coating. Never heard of such risk. Everyone cleans vintage glass with isopropy, don't they?

Please see pics below.

nail33 Senior Member • Posts: 1,054
Re: Isopropanol destroyed coating

I don't know myself, but here are the active ingredients in Zeiss lens cleaning wipes:

https://www.zeiss.com/content/dam/Vision/Vision/International/Pdf/en/data-sheet-for-zeiss-lens-cleaning-wipes.pdf

ProfHankD
ProfHankD Veteran Member • Posts: 9,146
Re: Isopropanol destroyed coating
5

sssboa wrote:

So I had a ring of mist on the inside of the rear glass of a vintage meyer-optik lens from the 1960's or so.

I used isopropanol to remove it, it worked but also removed the coating. Never heard of such risk. Everyone cleans vintage glass with isopropy, don't they?

It's possible that the "ring of mist" had already damaged the coating or hidden existing damage, but rubbing with anything is always a risk.... Some coatings are known to be very fragile, but mostly it's ones used on internal elements.

If the culprit was the isopropanol, then you should be able to easily remove the rest of the coating, which I'd suggest is probably better than leaving it as you have shown it.

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OP sssboa Junior Member • Posts: 32
Re: Isopropanol destroyed coating
3

So now having experience after cleaning many lenses. If the coating is damaged by mould/fungus/oxidation you rub it with anything and it will come off, be it alcohol, be it distilled water!

barbara j Contributing Member • Posts: 781
Re: Isopropanol destroyed coating
1

Just out of curiosity, were you using a cue tip? They are extremely scratchy these days, many not even cotton.

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OP sssboa Junior Member • Posts: 32
Re: Isopropanol destroyed coating
1

no, microfibre cloth

barbara j Contributing Member • Posts: 781
Re: Isopropanol destroyed coating
1

sssboa wrote:

no, microfibre cloth

I asked because I wondered at the grooves. Those must be where the fungus etched the glass. If the glass is etched I don't see a solution other than replacing the damaged element. And will you have gotten all of the fungus spores out. Fungus is contagious. It would have to be a very special lens, and even then I wouldn't keep it with my other gear.

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artichokes Regular Member • Posts: 127
Re: Isopropanol destroyed coating
1

Bought a Tamron 200-500 in A mount awhile back that had a severe fungus buildup on the back of the front element. Searched online and found a recommendation to remove it with a 50/50 solution of regular household ammonia and hydrogen peroxide. No scrubbing was required, rinsed with distilled water and reassembled it. Works great.

OP sssboa Junior Member • Posts: 32
Re: Isopropanol destroyed coating
1

No, I don't think it will spread There must be right conditions for fungus to develop. There is fungus everywhere around you, you won't escape it, it's in the air you breathe it's everywhere, no matter what you do it's gonna grab hold of you!

hypercore360 Senior Member • Posts: 1,951
Re: Isopropanol destroyed coating
1

You say you "Never heard of such risk". Did you investigate before applying the iso.?

sssboa wrote:

Hi,

So I had a ring of mist on the inside of the rear glass of a vintage meyer-optik lens from the 1960's or so.

I used isopropanol to remove it, it worked but also removed the coating. Never heard of such risk. Everyone cleans vintage glass with isopropy, don't they?

Please see pics below.

OP sssboa Junior Member • Posts: 32
Re: Isopropanol destroyed coating
1

Yes.

It doesn't matter what you use, if the coating is bad you will rub it off with holy water from the pope.

hypercore360 Senior Member • Posts: 1,951
Re: Isopropanol destroyed coating

Doubtful. But believe what you like. No argument here either way.

sssboa wrote:

Yes.

It doesn't matter what you use, if the coating is bad you will rub it off with holy water from the pope.

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