I believe a previous lab I used (now defunct) used to offer this service (at one's own peril).
If I understand it, it involves a fairly noxious chemical (Mr. Ryser?).
Our current lab just shook their heads sadly at our question, giggling.
Is this done anymore?
Advisability?
Thanks!!!!
I order an anti-reflective remover from Hilco it works well on most of the inexpensive A/R's.
Trish Hammons ABOC
Years ago I was stripping a pair of lenses when I suddenly sneezed over the stripper....burnt my nose! Nasty stuff. I think you'll do more harm than good. Might work on the old AR with CR39 lenses, but with the newer materials, you run the risk of crazing the lenses more and making it worse. Wouldn't risk it. I usually recommend the patient use those as back up glasses and get a new pair. Not worth the risk.Originally Posted by drk
I've used etching cream that I purchased at an arts and crafts store.
Actually the only chemical that removes ...................
Actually the only chemical that removes the glass (Sio2) layer is "Hydrofluoric acid."
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. It is a precursor to almost all fluorine compounds, including pharmaceuticals such as fluoxetine (Prozac), diverse materials such as PTFE (Teflon), and elemental fluorineitself. It is a colourless solution that is highly corrosive, capable of dissolving many materials, especially oxides. Its ability to dissolve glass has been known since the 17th century, even before Carl Wilhelm Scheele prepared it in large quantities in 1771.[2]
Because of its high reactivity toward glass and moderate reactivity toward many metals, hydrofluoric acid is usually stored in plastic containers (although PTFE is slightly permeable to it).
Hydrofluoric acid has a variety of uses in industry and research. It is used as a starting material or intermediate in industrial chemistry, mining, refining, glass finishing, silicon chip manufacturing, and in cleaning.[5]
(above copied from Wikipedia)
I have made and sold our own version of an AR Stripper around the world since 1984 and for many years as the only supplier. It contains only 12.5% of acids, (4.3 % of HF) mixed with 2 other acids, so it will not produce any immediate danger when small parts are absorbed by the skin.
It removes an AR coating in seconds, but works only on CR39 and will damage other lens materials like Polycarbonate and high index. It will turn them into a non reversible milky white.
It will also remove scratched dipped hard coats on CR39 material if left longer in the solution.
Said all this, the conclusion is, that if you use only CR39 material for AR coatings they are easily repairable and can be stripped at any later date.
Last edited by Chris Ryser; 08-17-2016 at 08:16 AM.
I have had nothing but problems with the anti-reflective coatings in terms of how long they last, even when using the correct cleaning methods - so I no longer get them.
When your automobile gets all scratched, dented and nasty looking you get a new one. Why not your lenses. Do you really want these things to last forever like back when we made them from glass. C'mon get with the program. Sell new lenses. It creates jobs and generates profits for the shareholders.
Help make America great again. Sell more lenses and frames.
Our lab will do it, reluctantly. It will ruin poly I know for sure!
Help make America great again. Sell more lenses and frames ..................
Hey Dick..............did you not know that they closed many labs and moved them to China + Mexico.
You should have said:
Help make China and Mexico great again. Sell more lenses and frames
We do strip, but only on the lower-end/basic AR Coatings. When it comes to the higher end coatings, it really doesn't work too well. The lower-end coatings tend to be run with a spin coat, which is softer, so the AR comes off a little easier. With our better coatings, even with the acid, we get patches that don't want to come off, so we don't do it.
That being said, we typically don't have the need in the first place to strip a good coating, as they don't have a crazing/peeling issue like cheaper coatings do.
Salam alaikum kissanime and welcome to Optiboard!
I find the very best AR coats will perform and last much better but are also much more expensive.
The coating is best made in a multi layer stack where the first coat is a hard coat to whatever lens you are using. If the lens is from a company like Zeiss a Zeiss coat should be used. The large international lens companies specifically match their hard coat to be compatible and provide the best adhesion for the AR stack.
Tunisians' may have problems with any AR due to excessive heat. They should not be exposed to temperatures greater than 54C (130F) so left in a car the lenses can craze.
Fester you're a man of the world, like James Bond, Indiana Jones, or Dora the Explorer.
My heartfelt gratitude to the experience and generosity of the posters of Optiboard, and to the site and owner himself.
I wait for the opportunity to return some favor.
Hemingway, but drinking Gordon's Vodka and Schwepps tonic water. Some day we must meet and drink at Harry's in Venice. We can talk about Belmonte. A very brave bullfighter.
If you are interested in high quality AR check out Hoya's substrate matched coatings. They are unbeatable for durability.
We use the acid and it seems to work on all ARs but we never use it on poly. Hi-index is a risk but usually comes out fine.
Have I told you today how much I hate poly?
What I should say is, we strip all ARs, but really it is only the basic stuff that isn't being warrantied. Usually anybody that wants us to strip AR had a set from who-knows-where or the lenses are 10 years old.
Have I told you today how much I hate poly?
http://ggweather.com/heat/heat%20study.pdf
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
My heartfelt gratitude to the experience and generosity of the posters .............
What a nice thank you post, for all the experienced and knowledgeable first class answers on AR coatings removal on this thread.
Hydrofluoric acid is really nasty stuff, deadly in fact. I keep many substances in my shop including many acids. I will not use Hydrofluoric acid, deadly or Hydrochloric acid, the fumes turn all the steel in the shop brown. Keep away from hydrofluoric acid, it crosses the skin barrier , causes tissue necrosis displaces the calcium in your bones and screws up your blood chemistry, then you die.
He has a strong point. Hydrofluoric acid is particularly bad news. I won't work with it either.
After Prop 65 I've come to the conclusion that everything I work with wants to kill me. At least Hydrofluoric acid is obvious about it.
Have I told you today how much I hate poly?
My partner swears by this stuff. Charges $25. Only tried it with poly.
http://www.dynamiclabs.net/chemicals...chemicals.html
Chris, we bought a bottle of OMS Anti_reflex Coating Stripper but it had no effect on the 7-layer halide coating that we use on sapphire lenses. We don't make these for consumption on eyeglasses, but for crystals on watches and lenses for lasers. We have a need to strip about 50 lenses at a time and the only way we have found to do it is by machine polishing, and that is iffy baded on using diamond polish or some polishes just slightly softer than sapphire, and it is rather time consuming. Our lab people have a chemical that they use to clean the deposition chamber but that chemical has no effect on removal of the AR coating on sapphire watch crystals. Could you lead us in an direction that may be more productive for us.
the acid mix dissolves and removes the SIO2 ........................
rnrprof, ...........the acid mix dissolves and removes the SIO2 which is the basic AR layer, but if you have multiple layers of metal oxides you will have to remove them mechanically.
We have a need to strip about 50 lenses at a time and the only way we have found to do it is by machine polishing, and that is iffy baded on using diamond polish or some polishes just slightly softer than sapphire, and it is rather time consuming.
If there is a chemical way to do it it would most probably be another lengthy research program.
It should be possible to use an acid strong enough to attack the metal oxide, the only problem is, anything that can do that will destroy the substrate underneath as well. You'd really need a master of metallo-inorganic chemistry. I wish I could help, but that's way outside my area of expertise in chemistry, in fact, its the exact opposite. My area is bio-organic chemistry.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
Bookmarks