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Cleaning optics with polymer lens cleaner, what about liquid masking film?

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#1 UWastronomer

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Posted 12 March 2018 - 12:13 PM

I was intrigued by the First Contact polymer lens cleaner, and noticed it looks an awful lot like a premium fluid mask used in painting models or rc car lexan bodies. I do not know the chemical makeup of either, but it looks to be a similar tacky (physical description not a quality) fluid that dries and peels off clean.

We're not detecting gravitational waves with our telescopes, but we do want to protect our glass and AR coating from debris and scratches.

So, has anyone used fluid mask before? Its a lot better price than $180 a bottle if it will do the job for us, several manufacturers offer variants, here is just one:

http://skycandylight...m-16-oz-bottle/
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#2 TOMDEY

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Posted 12 March 2018 - 12:52 PM

Hi, UWastronomer, I remember we had something like that at work (aerospace optics labs) that we just casually called ~strip-coat~ I'm almost positive it was sold as optical surface protection, but could well be the same generic formula that you are looking at. The techs would flow or paint it on, rather generously, right onto (really good!) mirrors for storage in these huge drawers. It was a sight for us optics guys to drool over (without harming the coatings!) big 2ft x 3ft drawers casually labeled 2-inch, 3-inch, 4-inch, 6-inch, 8-inch... the bigger ones stored in cases up to 16-inch. Even bigger ones slid in crates under the giant Newport tables. And yet gianter ones spirited off using fork lifts, to one of the warehouses. Yikes! I also recall peeling the strip-coat off; came right off in one single, benign sheet with pristine, dust-free surface underneath... ready to use! For some reason, this stuff fell into disuse. Either we were just too busy to bother, or maybe word came down to stop using it. Might also be that the stuff is volatile and considered a fire-hazard?! When liquid, it smelled good, same way that turpentine, carbon tet (?!) or ether smell good... It was bright orange, which probably means nothing. I might get a bottle of your referenced there ~for home use~ I wonder if this might be a way to ~clean~ a telescope mirror in-situ?! Seems it would lift the dust and maybe even other stuff... or ruin the mirror (doubt that). I tried to borrow the CO2 ~snow machine~ from work, to clean my scope in the observatory... they wouldn't let me... sigh. The strip-coat also came in a clear form. Related anecdote: One of the interns complained that all the new 4-inchers had bad wavefront. We checked his interferometer set-up. The (clear) strip-coat was still on the mirrors!  Tom


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#3 havasman

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Posted 12 March 2018 - 01:03 PM

Even cheaper are the proven combinations of a few gallons of distilled water, a drop of Dawn, fingertips, cotton balls, isopropyl alcohol, Kimwipes, cotton swabs, care and patience. Safe, effective and sure.

 

Or you can risk unproven concepts. But it will be bad form to come crying after failure.


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#4 starcanoe

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Posted 12 March 2018 - 01:13 PM

If it is better than Windex for cleaning optical surfaces...I'm all in....



#5 NiteGuy

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Posted 12 March 2018 - 01:41 PM

I tried First Contact on a small 4.5" mirror as a test. Even though it was applied heavily, as per exact instructions, I had a real problem getting it to release, even after several days. Finally, a couple of weeks later, I picked up the mirror again and the First Contact easily peeled right off, all in one piece. Sound great, right? Wrong! The mirror's surface was a terrible mess, the First Contact had done absolutely nothing in the way of cleaning. No difference whatsoever. Yes, I was shocked, after all, this stuff is crazy-expensive.

 

This had me thinking that the mirror's surface might not just be real dirty but maybe the coating's shot. Since this test mirror was not my own, I worried about applying First Contact a second time. Frustrated and disappointed, I got out the alcohol and did it the old fashioned way. To my amazement, the mirror cleaned up quickly and easily and looked like new when I finished.

 

I've read the testimonials, so I know First Contact works well for many individuals and observatories, it just didn't work at all for me. They recommend testing it on a small part of the mirror's coated surface before cleaning the entire mirror. That doesn't sit well with me at all. Something that expensive and your mirror's coating might be at risk by using it? What if it tore a chunk of your coating off with the test? What then? It also has a limited shelf life (several years, if I remember correctly), complicating things more. For what it costs, it should last indefinitely in my opinion.



#6 NiteGuy

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Posted 12 March 2018 - 01:54 PM

If it is better than Windex for cleaning optical surfaces...I'm all in....

You could buy a truck load of Windex for what this stuff costs.

 

Crazy as it sounds, I knew someone once who cleaned our club observatory scope's 16" mirror with Windex and paper towels! I think someone in the club might have actually gotten a lynch mob together. I kept watching the daily newspaper looking for a headline like, "Astronomy Club Lynches Club Member Caught With Windex."


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#7 MrJones

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Posted 12 March 2018 - 02:00 PM

I was intrigued by the First Contact polymer lens cleaner, and noticed it looks an awful lot like a premium fluid mask used in painting models or rc car lexan bodies. I do not know the chemical makeup of either, but it looks to be a similar tacky (physical description not a quality) fluid that dries and peels off clean.

We're not detecting gravitational waves with our telescopes, but we do want to protect our glass and AR coating from debris and scratches.

So, has anyone used fluid mask before? Its a lot better price than $180 a bottle if it will do the job for us, several manufacturers offer variants, here is just one:

http://skycandylight...m-16-oz-bottle/

I haven't used either of these but have used other liquid films. Anyway a possibly difference is the First Contact is supposed to remove oils including fingerprints while I doubt the water based hobby liquid masks would. The First Contact price does seem ridiculous which is why I haven't used it and probably never will.



#8 TOMDEY

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Posted 12 March 2018 - 04:03 PM

Even cheaper are the proven combinations of a few gallons of distilled water, a drop of Dawn, fingertips, cotton balls, isopropyl alcohol, Kimwipes, cotton swabs, care and patience. Safe, effective and sure.

 

Or you can risk unproven concepts. But it will be bad form to come crying after failure.

Yeah, that's a prudent approach! But the converse, "Nothing ventured; nothing gained!" We were ALWAYS doing crazy stuff in the labs. Especially the risky stuff like, "Worst that can happen is we ruin this 1/20 wave sixteen-inch plano... so we just grab another one." Actually, it was Amazing how well our techs could clean up badly-abused optics. I'd always bring stuff in from the shop floor (actually high-bay clean room), and return a couple hours later with it looking brand new, just sitting there on one of the benches. At home, I had a horridly-stained mirror (24-inch class?) Just for fun, I went to the Hardware store and bought every solvent they had: turpentine, kerosene, gasoline, carbon tet, caustic, sulfuric, nitric, furniture stripper, cough syrup, Bengay... the only thing I (prudently) didn't try was hydrofluoric acid [well, I just tried it on a teeny-weeny spot on the side] After that failure, it was a 3-hour drive to EMF, where they stripped, cleaned and coated it with enhanced aluminum! That fix only cost $2K, and I was back in business, no harm done. Understandably, the more conservative scientists called us ~Loose Cannons~ We took that as a badge of honor. And, no coincidence, we were the guys that management came to, when they really really had to get something done, [other scientists scattering like roaches] Probably our military backgrounds... we thrived on risk.  Tom

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#9 starcanoe

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Posted 12 March 2018 - 08:04 PM

You could buy a truck load of Windex for what this stuff costs.

 

Crazy as it sounds, I knew someone once who cleaned our club observatory scope's 16" mirror with Windex and paper towels! I think someone in the club might have actually gotten a lynch mob together. I kept watching the daily newspaper looking for a headline like, "Astronomy Club Lynches Club Member Caught With Windex."

 

In case anyone was still wondering....the windex line was a joke...



#10 starcanoe

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Posted 12 March 2018 - 08:06 PM

I like the sound of "Al stripper"....just saying...



#11 Oregon-raybender

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Posted 13 March 2018 - 12:37 AM

It does work well, it does require training. We used it on special and high cost optics for protection, then it's worth it's cost on a $2K lens or mirror. This type of product has been around for decades, we used a 3M product back in the 70's. I prefer methods used for years, the only change is using 3M's Novec engineering fluid for special solvent cleaning and chalk for stains. A mix distilled water, AL and baby shampoo is all one needs for most cleaning.

 

 

Starry Nights



#12 TOMDEY

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Posted 14 March 2018 - 10:08 PM

I like the sound of "Al stripper"....just saying...

Just what you want to dunk your precious mirror into. At work, we also had Gold Stripper and the nasty Chromium Stripper! And, back when I was with the band overseas, I was the drummer, playing dance routines for exotic dancers. It was heavenly.  Tom


Edited by TOMDEY, 14 March 2018 - 10:09 PM.


#13 bmwscopeguy

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Posted 08 July 2018 - 08:06 AM

There's also something called Rigid Collodian - sometimes marked/sold as 'scarring' fluid used for generating 'scar' tissue as it contracts and pinches the skin when it dries.

 

It also smells like ether, something that TomDey remarked on. 

 

I have used this rigid collodian with good results.  It works the same way as the polymer film, but is a lot less expensive. You can buy it on eBay.

 

Malcolm


Edited by bmwscopeguy, 08 July 2018 - 10:45 AM.

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#14 jwestervelt

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Posted 08 July 2018 - 08:15 AM

Now if only someone made AR Stripper!  :D  Sucks when you have a piece that has a damaged AR coating and no way to re-coat it.



#15 gregj888

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Posted 08 July 2018 - 10:14 AM

Ive used spray Rustolium to protect new gas when lens making.  Ons side polished, then coat it with a couple of coats of paint to protect while working on the other side.  Came from the Newport lens making ap-note.

 

A little warm water loosens and it comes off in a sheet.

 

Edit: would be real careful with this on a coated optic...


Edited by gregj888, 09 July 2018 - 09:53 AM.


#16 ccaissie

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Posted 09 July 2018 - 06:15 AM

One member wanted to try collodion on Dr Gerritson's 18" mirror.  Must have been the "wrong collodion"....total miserable mess...needed recoating.

 

Any ideas on why that was a mistake?   What are the varieties in "collodion"?



#17 bmwscopeguy

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Posted 09 July 2018 - 06:58 AM

 We'd need to know what was meant by total miserable mess? 

 

How thick did they put it on?, how long did they let it dry before attempting removal..?? What condition was the 18" optic in before attempted cleaning? Had the member ever used colloidal in a smaller optic?

 

I'm sure that there are different 'classes' of colloidal - but it terms of what is available to we amateurs - there only seems to be the one source.



#18 Oregon-raybender

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Posted 09 July 2018 - 11:56 AM

Professionals stopped using colloidal based materials decades ago, do to the chemicals used and the learning curve. It was not cost effective or worth the risk and health of our employees or the optics. We saw no reason to use it, because simple cleaning methods and materials are available that work better.

 

Yes, we do use a protection lacquer or paint on side one optics when the other side is in process or a secondary process (like edging)

 

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#19 Oregon-raybender

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Posted 12 July 2018 - 02:09 AM

SDS sheet on collodion. You can see why professionals stopped using it. Safety first graduate.sml.gif

 

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https://www.delasco....df/collodio.pdf



#20 don clement

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Posted 12 July 2018 - 10:13 AM

Collodion USP works well for me. IMO the dangers  of using collodion USP are blown out way of proportion to promote the very expensive commercial polymer replacement product. The next thing we will hear are the dangers of grinding mirrors. Remember Bob Cox died from emphysema due to grinding mirrors.  

 

Don


Edited by don clement, 12 July 2018 - 10:18 AM.


#21 bmwscopeguy

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Posted 12 July 2018 - 10:51 AM

I agree - Collodian is highly flammable, and it's fumes are potentially dangerous.....but the same can be said of gasoline or enamel spray paint - both things we give absolutely no thought to using...

 

Observe the same precautions as when fuelling your car (ie: don't smoke and don't inhale the fumes) and you'll be fine.

 

I have found that collodian works better if it put on fairly thick. Too thin and it tends to come off in pieces instead of a sheet.

 

Malcolm


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#22 ed_turco

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Posted 12 July 2018 - 11:37 AM

Collodion USP works well for me. IMO the dangers  of using collodion USP are blown out way of proportion to promote the very expensive commercial polymer replacement product. The next thing we will hear are the dangers of grinding mirrors. Remember Bob Cox died from emphysema due to grinding mirrors.  

 

Don

Bob Cox died from rapid grinding of exotic optical glasses.  No setups with safety in mind; they should have known; the philosopher, Spinoza died from inhaling the particles in the air from his lens grinding which was a sideline to his philosophizing.  What was that;  three hundred and fifty years ago?


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#23 don clement

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Posted 12 July 2018 - 12:44 PM

Exotic optical glasses like Pyrex? Oh the dangers involved with mirror making. Next will be the danger of silvering one's own mirror as shown in the ATM books.  BTW there is a current thread on the drill press which is a very dangerous machine tool. Being a TN is very dangerous.

 

 

Don


Edited by don clement, 12 July 2018 - 12:51 PM.


#24 bmwscopeguy

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Posted 12 July 2018 - 01:19 PM

Come on guys - we live in an overcautious society.  Any requirements to observe basic common sense has been bred out of a lot of people.... So it doesn't hurt to remind them of potential hazards - just so we don't dwell on them.

 

I have a old Lindsay book reprint at home - I think it's called the 'Boy Mechanic' or some-such and it makes for fascinating reading. Back then, asking a 10 year old boy to go out and procure a litre of Sulphuric acid was given the same amount of caution as if you were sending him out for a loaf of bread. It was expected back then that he knew how to weld and work a drill press too. Somehow we all survived.

 

As a counterpoint to this, I have a current Meade GOTO scope and the manual specifically cautions not to get too close to the scope in case of 'sudden unexpected movement' (all of 5* per sec.....) The lawyers no doubt had visions of ears and noses being lopped off be a frenzied Ginzu GOTO mount...lol

 

Also interesting is the fact that the main retail use for collodian is to brush it on your skin to create puckers that approximate scar tissue for Halloween makeup purposes. (and yes, I am aware that tetraethyl lead was used as food flavour enhancers, and early cosmetics used radium before the dangers were appreciated...)



#25 don clement

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Posted 12 July 2018 - 01:41 PM

One should take precautions when making a telescope like this from the Henry Ford Machining book. 

Adding text to the numbers is left up to the TN.

 

henry-ford_zps46ebc3a6.jpg




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