Trying to Prevent Filter Glass Oxidation #2

[Andrea B.]

And so, my dear UVP Members, I had yet another AHA! thought. (The audience chuckles.)

 

I got to thinking that if there were some kind of covering which fit right up against the glass, then that would prevent (most of) the oxidation/moisture degradation of a filter. But I was not sure what material would work for this?

 

Paper was an obvious, easy rejection because most paper also deteriorates over time. And besides paper would absorb moisture.

 

So how's about using Saran Wrap I wonder?? You could stick that stuff to the glass easily. But what the heck is it made of? This led me on a merry 2-day chase through the brambles and vines of the Internet where I eventually made an interesting find.

 

As for Saran Wrap I learned that when the its manufacturers switched from making it out of PVC and began using LDPE, the stuff became less clingy. I do not buy Saran Wrap myself, so I did not realize it no longer clang was clingy. If protecting filters, one would want clinginess, don't you think?

 

Of course, the major issue is whether or not Saran Wrap is chemically inert. I learned that it is quite resistant under normal temperatures, but it has some flaws. For example, breaking down under solar radiation to produce methane is really not a good characteristic to have in this time of climate change. We have enough cows already on the planet so I don't want to see Saran Wrap cowing it up even though my Saran Wrapped filters would most likely be in a dark closet. Anyway, forget Saran Wrap, just too many side effects and not complete resistance over time.

 

[side Note: Why are there still people asking the makers of Saran Wrap whether they can use it in the oven? Wouldn't you think people would know by now not to do this? Oh well.]

 

Next question was: Could I cut circles from Ziploc® bags to place over filters? Nope. They are made from LDPE and LLDPE. More cows. So start searching for inert plastics. And let's make this long story short by getting to the point.

 

My Saran Wrap speculation and internet journey eventually led (again) to this:

First Contact ™ Polymer Optic Cleaning Kits. Go check this out !!!

 

See also: https://www.photoniccleaning.com/

 

You can use this red polymer both as a cleaner and as a protector. Swab it on, let it dry to a "robust film", peel the film off and you have a pristine filter. Or swab it on, let it dry and you have a protective coating for stored filters which "provides an excellent barrier to oxygen, sulfur, and water vapor". What's not to like about this!!??

 

OK, perhaps that was slight over-enthusiasm, heh-heh. This stuff is rather expensive? We learn that 1 ml of red polymer solution can clean about (6) flat and smooth 1 inch optics. The basic (US)$161 Optic Cleaning Kit contains 73 ml of red polymer and 30 pull tabs. Using π you can figure out just how far this will go for your particular filter set.

 

I'm going to try some of this stuff. It really seems like the best solution found thus far.

 

What do you think about this?

[Cadmium]

The best way to do that is coating or clad. But I still prefer the simple method of maintaining filters on a regular basis if you are not using them often enough to check on them by default.

Use it or lose it...

[Andrea B.]

Yes, this red polymer is a coating.

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P.S. Before anyone reminds me, I **do** know that I have in the past actually mentioned and linked to the First Contact Polymer Optic Cleaning Kit!!! :lol: But at that time, somehow, it did not register exactly how cool this stuff would be for protection and I just forgot about it.

Linkie from 2016: https://www.ultravio...dpost__p__14203

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Has anyone tried First Contact?

It has been used for cleaning telescope mirrors and you know how fussy astronomers can be about telescope mirrors. So I think we are OK in surmising that First Contact is safe against high quality glass.

 

 

.

[Andrea B.]

So why no comments here? Here is your best solution (so far).

• --> Clean the filter then paint it with the peelable polymer film.
  

 

I've ordered mine. I figure the red polymer expense is OK given the investment many of us have in our filter set.

 

For now, I will use this only on uncoated glass. I need to know more before trying it on any coated filters.

[Andrea B.]

FAQS about First Contact polymer film: http://www.photonicc...m/FAQ-s/107.htm

 

 

Does First Contact™ protect against oxygen?

Yes, First Contact™ provides effective protection from oxygen. The dry, First Contact™ film is impervious to oxygen.

 

 

What will First Contact™ clean from the surface?

First Contact™ can clean any surface that is not soluble in strongly polar organic solvents such as acetone or ethanol,including all types of glass, metals, silica, Si, Ge, KRS-5, NaCl, KBr, and all polar inorganic crystals. It works on frosted glass, diffuse reflective and even many anodized surfaces! First Contact™ even cleans AR and reflective coatings, most commercial first surface mirrors (protected and unprotected), and some plastics, for example nylon and Delrin®, that don’t dissolve in polar organic solvents such as acetone. First Contact™ possesses a perfectly balanced adhesive force to hold the residues without holding onto the many expensive precision coatings in use on today’s optics.

[Andrea B.]

Can First Contact™ clean camera lenses? (Note: do not use on some plastics)

Camera lenses, lens housings, and mounts may be composed of or contain plastics. Caution must be exercised when using First Contact™ to clean camera lenses.

Professional and research equipment lenses are typically made with glass and high quality coatings. First Contact™ is safe to use with these lenses. Many professional grade lenses have metal housings and mounts which will not dissolve in the First Contact™ solvents; it is best not to coat all the way to these edges as the First Contact™ film will be more difficult to remove. Even so, exercise caution and do not coat all the way to the lens housing or lens mount if there is any chance these structures are made of or contain plastics. Optic retaining rings can be protected from the polymer using our Oring Procedures to control polymer flow. Orings are available on our webstore. Photonic Cleaning Technologies will not accept responsibility for damage to an optic or instrument due to dissolved plastic components.

[Andrea B.]

What is the shelf life of First Contact Polymer?

 

Red First Contact Polymer has a shelf life of 9 months. (Don't buy too much!)

 

If stored below room temperature out of direct light, both formulas can last much longer. When exposed to light for long periods of time, the Red First Contact Polymer can begin to lose its color and eventually turn colorless. This in no way affects the polymer’s ability to protect and clean.

[Andrea B.]

Does First Contact™ protect against water and water vapor penetration? (Read carefully!)

 

Yes, First Contact™ provides an effective barrier to water and water vapor.

 

The polymer film will swell in water and, if submerged, will lift off easily in a few minutes, especially with agitation. Some large scale manufacturing customers place a wet cloth/tissue on the dried First Contact film near an edge to release it from the surface then use a peel tab to remove the polymer entirely.

[Andrea B.]

The red polymer film is sold in serveral places. My list here is just the first 3 sites listed when querying Google for "First Contact red polymer".

• www.photoniccleaning.com
  This is the manufacturer's site for First Contact.
  

• https://www.edmundop...solution/14543/
  

• https://www.newport....c-cleaning-kits
  

[JCDowdy]

Has anyone ever tried an oxygen absorbent?

see: Oxy-Guard

[Andrea B.]

It was mentioned in some other recent thread. Thanks for this link though.

 

It's more the water vapor in air than it is the oxygen, per se. The oxidation/reduction reaction leaches ions (of alkaline earth metals) from the glass which form hydroxides (oxidation film) on the glass surface. Water + Magnesium Oxide (in glass) = Magnesium Hydroxide. (I no longer remember how to properly write the electron exchange.)

 

The glass SiO2 bonds can also be broken by atmospheric gasses. I don't think we are seeing that particular phenomenon.

 

I think I should go back and update a comment here and there which over-emphasized oxygen.

I have forgotten way too much chemistry.

[ulf]

This product is excellent for cleaning optical glass surfaces (maybe also sensors?)

I have professionally seen similar solutions for protecting and storing highly sensitive optical metal surfaces with very fine microstructures.

Some types of lacquers caused the most unexpected problems, only visible with a electron-microscope.

 

A few years ago there were a company trying this principle for sensor cleaning.

 

First Contact red polymer might be a modified type of PVA with well chosen additives.

If it works well together with the reactive chemicals in the filter glass types, normally causing problems, it will also be usable for hibernating filters for longer periods of time.

It will quickly become very expensive if used repeatedly for shorter periods of time, as during the more active period of UV-photography.

[SteveE]

OOOH! It's a butterfly.

Quick Honey, peel my U-360

[Cadmium]

Andrea, Looks interesting, hmm... anyone try that yet?

[rfcurry]

Andrea,

 

Have you tried parafilm? You may remember this from your chemistry days. Good ol' paraffin wax.

https://www.spectrumchemical.com/OA_HTML/lab-supplies-products_Parafilm-M-Self-Sealing-Film-2-in-x-250-ft-152-68319_304495.jsp?minisite=10020&respid=22372

 

Not cheap but has plenty of uses. Nice and stretchy, too.

[rfcurry]

Andrea,

 

I include anodized metal stacking caps with each of my filters. These, if used consistently, should reduce corrosion as they greatly reduce air flow over the glass. Do you use the stacking caps? Do they help?

.

[Andrea B.]

I have always stacked and capped my filters or stored them in the typical small boxes when not in use. I don't have any results from personal experiments about which might be the better practice. But it certainly seems reasonable to think that either is a good practice because it reduces exposure long term as you mention. But when the humidity is high, then capping or boxing is going to trap some of that humid air.

 

I love those anodized caps. I've used them since forever to make efficient, low volume (relative to boxing) filter stacks. And always happy to see some arrive with a filter order.