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Coating damage from cleaning?

Started by bartine, 11/30/2014 08:23PM
Posted 11/30/2014 08:23PM Opening Post
I sold a 22mm Nagler to a newbie here on Astromart.

When I sent it, it looked good. No issues. I didn't really see any dust.

Then - the guy sends me back a picture - claims " I thought the Nagler 22 just needed a cleaning, but turns out it appears to have major coating issues." and he sends me back this picture.

I feel horrible, and offer to give him his money back.

Attached Image:

bartine's attachment for post 58913
Posted 11/30/2014 08:27PM #1
I asked "What did you do" and he says -

" If you are wondering, it was cleaned the same way I clean all my TV EPs, using alcohol and cotton swabs per the instructions on the TV website. "

Realize - I didn't think it needed cleaned at all. But thought maybe I just missed it. Then in a later email he gives this thoughtful reply:

" However, I can promise you that I took the utmost care when cleaning, didn't do any hard rubbing on it, and stopped as soon as I realized the marks weren't from dew. "

I start thinking - how much did he "clean" it? Am I wrong to think he destroyed this eyepiece?

Ben
Posted 11/30/2014 08:36PM #2
I do not know about your issue, but once I loaned an eyepiece to another club member in order for him to see if he wanted one for himself. He later returned my eyepiece not to me direct, but to my place of employment & when I got it, it was not my eyepiece but one with a seriously scratched eyelens. Of course there was no proof of this exchange but I learned my lesson and also decided future club membership was not for me (an earlier event with another club one of my eyepieces was stolen out of my scope when I was not attending it). I'd suspect the new owner exchanged his for yours and is attempting to bilk you. What is one bad rating worth vs your otherwise excellent ratings?
Posted 11/30/2014 08:45PM #3
Hard to tell from the picture, but I much doubt the coatings are damaged. Coatings on these eyepieces are tough, camera lens tough.

Uncle Rod

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Posted 12/01/2014 04:30AM #4
Ben, it looks like the buyer MIGHT have got liquid between the lens while cleaning it. Years ago I cleaned a lens, and poured lens cleaning fluid on the top lens, the liquid went in between the lens, learned a lesson here. I was able to take it apart and clean and put the lens back together, This eyepiece was a simple four glass design, not like the complicated eyepiece of today.
If you have any marks you can recognize on the 22mm, I would have him to agree to send it back, You pay the shipping and not send any money until you have received and taken the time to examine it. I also fully agree with RON and ROB in their postings.
Posted 12/01/2014 06:13AM #5
The photo he sent is so bad it is hard to tell what is wrong here due to poor focus. But I agree that if you let him send it back you should identify both the EP and the problem before refunding.

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Posted 12/01/2014 08:40PM #6
Don't know what to tell you about what to do, but I would say that he's likely been playing around with cleaning.

What would I do? I'd tell him if that is what it turns out to be, I will refund him his money MINUS what TV charges to clean it and reassemble it plus shipping. wink

Uncle Rod

Time on your hands?
Waste it with Uncle Rod's Astro Blog!

http://uncle-rods.blogspot.com/
Posted 12/02/2014 05:41PM #7
Tough one. I was a vac-coating engineer for 10 years, among myriad other things and know enough to keep hands off. I have myriad old TeleVues (including the original 20mm Nagler!) with coatings still wonderful. FYI, most all MARC coatings are many layers of alternating TiO2, SiO2 which are considered "hard" coatings AKA as hard as the glass and able to withstand moderate cleaning. Preferred sequence is (as needed) DI H2O, isopropanol, acetone. On eyepieces I go right to the iso to dampen a Q-Tip, and have never had to go beyond that. All it takes is one aggressive "cleaning" by someone who thinks he's scrubbing eyeglasses with a T-shirt and can ruin it. But the customer sounds sincere. I would take it back and eat the loss even though it might be his fault. If you could look at the PMs at the BIG professional observatories, you'd be amazed! Most all are FILTHY from use yet perform well. Recommended coating houses for readers: Cary at OWL and Evaporated Metal Films for really big stuff. I'm drifting off topic so will bid adieu. Tom Dey

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