Author Topic: How to remove the coating from a lens?  (Read 4484 times)

Macro_Cosmos

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Re: How to remove the coating from a lens?
« Reply #15 on: May 15, 2018, 06:15:00 »
Image quality will be drastically reduced if you do that. I suggest buying a lens that works well in the UV range. Bjorn's site has an excellent list  ;D

If you don't mind, it's still a fun project. Keep in mind that some glass elements are actually doped with various substances, rather than coated. These doped glass could affect UV transmission as well.
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Steven Paulsen

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Re: How to remove the coating from a lens?
« Reply #16 on: May 16, 2018, 18:19:50 »
I worked as an optician for many years & I discovered this trick on my own. (Use at your own risk, & this applies to plastic & glass eyeglass lenses.)

The coating always scratched & even flaked off on earlier applied coatings. I removed the lenses from the frame & soaked them for a few hours in common drain cleaner, a mild version of sulfuric acid. It did not effect the hardened scratch coating on common CR39, (plastic,) and no issues on glass, either.

This may work, if you can remove a lens element of your photo lens. I would be cautious of "wiping a lens' If you have a pair of glasses with damaged anti reflective coating, you can bring them back service using the above method.

pluton

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Re: How to remove the coating from a lens?
« Reply #17 on: May 16, 2018, 22:55:17 »
I removed the lenses from the frame & soaked them for a few hours in common drain cleaner, a mild version of sulfuric acid. It did not effect the hardened scratch coating on common CR39, (plastic,) and no issues on glass, either.
While your experience with using drain cleaner to remove AR coatings is useful knowledge, in the interests of safety and accuracy, I submit to the forum that in the USA, the common drain cleaners are not acidic but strong alkalis, in most cases sodium hydroxide.
MSDS's from two common brands:


Keith B., Santa Monica, CA, USA

ArthurDent

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Re: How to remove the coating from a lens?
« Reply #18 on: May 16, 2018, 23:42:24 »
While your experience with using drain cleaner to remove AR coatings is useful knowledge, in the interests of safety and accuracy, I submit to the forum that in the USA, the common drain cleaners are not acidic but strong alkalis, in most cases sodium hydroxide.
MSDS's from two common brands:

This is correct. I don’t know how it is done elsewhere, but in America, drain cleaners work by reacting the built up grease with a base (NaOH) in a saponification reaction to form a soap which is easily dissolved with water and flushed down the drain.

Steven Paulsen

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Dear Drano Police
« Reply #19 on: May 17, 2018, 04:45:16 »
Sorry. I assumed it was all the same. I buy the expensive stuff that is only carried in a few hardware stores. A one quart plastic bottle, with a heavy plastic bag, over wrap. It costs Around $15.00, and lists the active ingredient as sulfuric acid.

I have a mix of copper, iron & pvc in my home. A couple times upon dumping in a small healthy dose, I've gotten a rise of smoke. I am an old, photographer, musician, (long hair, hippy type.) The stuff takes care of hair clogs quickly. (Dump, vacate, wait a minute or two & rinse with cold water. I'll also add, the low cost domestic stuff does the job, on lenses, but not near as fast. (Usually an overnight soak & is fairly useless on bath tub, shower clogs.)


My apologies, and/or, GFY
 8)

Dr Klaus Schmitt

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Re: Dear Drano Police
« Reply #20 on: May 22, 2018, 08:47:56 »
I still think this approach is not a valid one, gettting a (cheap) UV capable lens does the trick much better....
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