Damaged coating on lens after camera repair

FrancoD said:

On previous threads about this the advice (for recent lenses...) was to replace the element. Of course this does not work for your situation but the point is that in general re-coating is not a practical solution.

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aenoether said:

Hi all,

A while ago I bought an Agfa Isolette II but it suffered from the dreaded Agfa green grease issue...ie the lens was stuck and wouldn't focus.

I've managed to loosen, remove the lens and clean the grease off the threads with the help of lighter fluid. Good news is the lens can now turn to focus. Bad news, as you can read from the title, is that it damaged the coating on the rear lens group. Now the lens is hazy. At first I thought it was residual grease on the lens so I hit it with more lighter fluid followed by lens cleaning solution. Unfortunately it hasn't cleared the haze. It appears I've damaged a lens coating.

Does anyone know if this can be fixed or will I just have to live with it?

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flektogon said:

aenoether said:

Hi all,

A while ago I bought an Agfa Isolette II but it suffered from the dreaded Agfa green grease issue...ie the lens was stuck and wouldn't focus.

I've managed to loosen, remove the lens and clean the grease off the threads with the help of lighter fluid. Good news is the lens can now turn to focus. Bad news, as you can read from the title, is that it damaged the coating on the rear lens group. Now the lens is hazy. At first I thought it was residual grease on the lens so I hit it with more lighter fluid followed by lens cleaning solution. Unfortunately it hasn't cleared the haze. It appears I've damaged a lens coating.

Does anyone know if this can be fixed or will I just have to live with it?

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Damaged coating should not blind (i.e. to leave hazy) lens. Try to clean its surface with a high concentrated (isopropyl) alcohol. But be careful, especially if that lens element is glued (balsamed) with another one. If alcohol penetrates between them, they could separate! So keep the lens (camera) downward, and wet a microfiber cloth with the alcohol, and then carefully clean the surface. Good luck!

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Overrank said:

Out of interest how did you loosen the grease ? I’ve got a Agfa Standard where the grease has gone solid. I’ve seen recommendations of hairdryers and leaving it in the sun to loosen it enough to be able to take it apart. My solution was to buy another but at some point I would like to try and fix my original camera.

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flektogon said:

Damaged coating should not blind (i.e. to leave hazy) lens. Try to clean its surface with a high concentrated (isopropyl) alcohol. But be careful, especially if that lens element is glued (balsamed) with another one. If alcohol penetrates between them, they could separate! So keep the lens (camera) downward, and wet a microfiber cloth with the alcohol, and then carefully clean the surface. Good luck!

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aenoether said:

flektogon said:

Damaged coating should not blind (i.e. to leave hazy) lens. Try to clean its surface with a high concentrated (isopropyl) alcohol. But be careful, especially if that lens element is glued (balsamed) with another one. If alcohol penetrates between them, they could separate! So keep the lens (camera) downward, and wet a microfiber cloth with the alcohol, and then carefully clean the surface. Good luck!

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"Hazy" is probably the wrong term since I know it has a specific definition for damaged lenses. The surface of the lens looks like it has a mat, slightly cloudy finish. It's still somewhat transparent though not crystal clear as it was in the beginning.

Question: Will lighter fluid also effect the balsam? I wasn't being careful which direction I held the camera while I was cleaning the rear group.

NB I don't know if each of the two groups are single element or muli-element lenses glued together.

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Overrank said:

Out of interest how did you loosen the grease ? I’ve got a Agfa Standard where the grease has gone solid. I’ve seen recommendations of hairdryers and leaving it in the sun to loosen it enough to be able to take it apart. My solution was to buy another but at some point I would like to try and fix my original camera.

Click to expand...

aenoether said:

Overrank said:

Out of interest how did you loosen the grease ? I’ve got a Agfa Standard where the grease has gone solid. I’ve seen recommendations of hairdryers and leaving it in the sun to loosen it enough to be able to take it apart. My solution was to buy another but at some point I would like to try and fix my original camera.

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I don't know if this applies to your camera but here's my tale of joy and woe.

I unscrewed and removed the front plate (that has the distance markers on it). Then I dripped Zippo lighter fluid where the thread was and tried to work it back and forward...it didn't budge. Tried that a few more times then gave up. I left it hoping that any residual solvent seeped into the thread and would continue to loosen the grease overnight.

Next day, with the help of more lighter fluid, a multi-grip tool and my husband's brute strength and ignorance, we managed to loosen and unscrew the front group. The metal sustained some cosmetic damage. I cleaned the remaining grease from the thread of the metal encasing the front lens group with more lighter fluid and a toothbrush. I sacrificed a new toothbrush to the repair gods for this task

The lighter fluid didn't affect the front lens elements so I got to work on the thread around the rear lens group. That's when I noticed the lens element on the rear group became foggy. Thinking I got green grease on the lens, I hit it with more lighter fluid followed by lens cleaning solution. The surface of the lens became rough and since I'd used lens cleaning cloth to avoid scratching the lens, I realised that the lighter fluid must have damaged a lens coating that was on this lens (it wasn't present on the front group).

Anyway, the front group now screws into the rear group, more or less easily, so I can adjust focus. I just need to calibrate the lens to infinity focus so I can test how much loss in contrast I have from the damaged coating.

Sorry for the long post. Hope there's some info that applies to your situation. My only advice is that unless you know for certain that your camera's lens doesn't have any lens coatings, then lighter fluid, as a solvent, should be your last resort.

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Ulrik Christiansen said:

Overrank said:

Out of interest how did you loosen the grease ? I’ve got a Agfa Standard where the grease has gone solid. I’ve seen recommendations of hairdryers and leaving it in the sun to loosen it enough to be able to take it apart. My solution was to buy another but at some point I would like to try and fix my original camera.

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I have fixed 2 of such lenses in Isolette cameras by dropping them in a small jar of Isopropyl alchohol (isopropanol, 2-propanol or propan-2-ol). After 24 hours I had luck taking them apart, though they were still pretty well glued together.

They work now and take fine pictures, so I don't think the chemical has done any harm.

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KCK14 said:

Old lenses sometimes had very soft coating on interior surfaces. As suggested your only real solution is to polish it off. That is better than leaving it damaged, (if the alcohol cleaning does not work)

Also a general note on solvents. I found that some lighter fluid seemed to not be pure naphtha and might have some lube mixed in. In my shop I used Coleman lantern fuel as it seemed. to leave no residue.

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Ulrik Christiansen said:

Overrank said:

Out of interest how did you loosen the grease ? I’ve got a Agfa Standard where the grease has gone solid. I’ve seen recommendations of hairdryers and leaving it in the sun to loosen it enough to be able to take it apart. My solution was to buy another but at some point I would like to try and fix my original camera.

Click to expand...

I have fixed 2 of such lenses in Isolette cameras by dropping them in a small jar of Isopropyl alchohol (isopropanol, 2-propanol or propan-2-ol). After 24 hours I had luck taking them apart, though they were still pretty well glued together.

They work now and take fine pictures, so I don't think the chemical has done any harm.

Click to expand...

KCK14 said:

Old lenses sometimes had very soft coating on interior surfaces. As suggested your only real solution is to polish it off. That is better than leaving it damaged, (if the alcohol cleaning does not work)

Also a general note on solvents. I found that some lighter fluid seemed to not be pure naphtha and might have some lube mixed in. In my shop I used Coleman lantern fuel as it seemed. to leave no residue.

Click to expand...

flektogon said:

KCK14 said:

Old lenses sometimes had very soft coating on interior surfaces. As suggested your only real solution is to polish it off. That is better than leaving it damaged, (if the alcohol cleaning does not work)

Also a general note on solvents. I found that some lighter fluid seemed to not be pure naphtha and might have some lube mixed in. In my shop I used Coleman lantern fuel as it seemed. to leave no residue.

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Oh, never ever use naphtha based solvent (even acetone) on lenses!!! Only and only pure alcohol.

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momotus said:

flektogon said:

KCK14 said:

Old lenses sometimes had very soft coating on interior surfaces. As suggested your only real solution is to polish it off. That is better than leaving it damaged, (if the alcohol cleaning does not work)

Also a general note on solvents. I found that some lighter fluid seemed to not be pure naphtha and might have some lube mixed in. In my shop I used Coleman lantern fuel as it seemed. to leave no residue.

Click to expand...

Oh, never ever use naphtha based solvent (even acetone) on lenses!!! Only and only pure alcohol.

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I agree. I never use anything stronger than Isopropyl alcohol, and have never seen the need for anything else.

There are some YouTube type recommendations for lighter fluid-- like using it to dissolve old grease in helicoids without disassembly and things lke that, but I'd never go there. Better to disassemble properly and clean up with Isopropyl.

Also be careful with cleaning cloths and brushes-- I stick to Kimwipes and cotton swabs, if possible.

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flektogon said:

momotus said:

Also be careful with cleaning cloths and brushes-- I stick to Kimwipes and cotton swabs, if possible.

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Careful with cotton swabs! They can cause micro scratches.

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momotus said:

flektogon said:

momotus said:

Also be careful with cleaning cloths and brushes-- I stick to Kimwipes and cotton swabs, if possible.

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Careful with cotton swabs! They can cause micro scratches.

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Yep! Point taken. Probably should avoid using on glass or mirrors...

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