I use the stuff myself and have encountered the tearing problem you
mentioned, as did Lee Hawkins. I am going to repeat his original post
below. I have gone to using a second coat to make the film more tear
resistant. I think instead of the stickers it is a better idea to paint
on one coat, let it mostly dry then do a second coat but have a small
piece if cloth near the edge which one wets the end of so it becomes part
of the film, then use the cloth as a tag to pull the whole film off. I am
very careful to try and avoid the very edge ;-)
Giles
>>>
To: olympus@xxxxxxxxxxxxxxx
Copies to: lhawkins@xxxxxxxxxxxxxxxxxxxxxx
Subject: [OM] Opticlean: The long-awaited review.
Date sent: Fri, 23 Jul 1999 21:10:50 -0400
From: "R. Lee Hawkins" <lhawkins@xxxxxxxxxxxxxxxxxxxxxx>
Send reply to: olympus@xxxxxxxxxxxxxxx
The masses (or at least Giles and Mahlon ;) have spoken. Here it is.
Actually, I wasn't being a slacker, I was just waiting until we cleaned our
24" to see how the stuff worked there. Enjoy!
Cheers,
--Lee
Review of Opticlean Polymer
By
R. Lee Hawkins
Whitin Observatory
Wellesley College
Opticlean is a polymer that you brush onto optics, allow to
cure, and then remove with sticky-backed "pull tabs" that look
suspiciously like mailing labels. It is used for cleaning both lenses and
mirrors (coated or uncoated). It is available from Dantronix
(www.opticlean.com).
I, like many of you, was thrilled when I first heard of
Opticlean Polymer. This magical polymer, which you brush onto your
optics, allow to dry, then peal off is advertised as leaving optics
"molecularly clean". While I have found it useful in cleaning optics, it
does have limitations, which I'll outline below. In most of the tests
below, I purposely put lots of greasy fingerprints on the optics before
cleaning them (but didn't allow the fingerprints to harden).
My first day of testing Opticlean was a dismal failure. I tried
the solution on 3 different optics: a Meade corrector plate, an old wide
angle Nikon lens, and a Zuiko 50/1.8. On the Meade, I had lots of problems
with the film tearing on removal, and leaving little patches of Opticlean
behind. On the Nikon (which has a fairly flat front element), it seemed to
work fine, but didn't clean off some old water spots. On the much more
steeply curved Zuiko, I had major problems getting the Opticlean to come
off at all. Needless to say, this experience left me wondering if
Opticlean was really all that it was advertised to be.
The following day, I contacted Jim Hamilton of Dantronix, the US
distributor of Opticlean, and he gave me some good hints to solve the
problems I was having. First, my coats of Opticlean were too thin,
leaving a film that was weaker than the film's bond to the optic.
Secondly, I was waiting for the recommended 2-5 minutes for the polymer to
cure, thinking that if I waited longer the polymer would set on the optics
and be difficult or impossible to remove. It turns out that just the
opposite is true: as Opticlean cures, it shrinks, and the bond to the optic
weakens somewhat. Jim indicated that for large optics with thick coats,
more time was necessary. Finally, Jim reports that Opticlean cannot deal
with such things as dried and hardened water spots, very old finger prints,
and the like. Those have to be softened first with methanol or some other
solvent.
This brings us to my second day of testing Opticlean. My
results on the Meades were much better. I both put on a thicker coat
and allowed the polymer to dry for about 30 minutes before pealing it
off. However, I still had problems with small patches being left behind
where I wasn't careful enough to get the coating on uniformly. Also,
Opticlean still didn't get my corrector plates "as new" clean. Dried
condensation is the bane of my existence here in the East US, and dried
condensation tends to "glue" small particles to optics when it dries. The
best way to remove these particles (and any small patches of Opticlean left
behind) is with Eclipse lens cleaner and PEC-Pads.
Next, I tried Opticlean on the edge of a 60+ year old front
surface mirror that is in the optical path of our spectrohelioscope.
This mirror has a hazy film on it, which I was hoping Opticlean would
remove. While I didn't have any problems this time with little spots
being left behind, Opticlean also did nothing to remove the hazy film! The
area I cleaned was indistinguishable from the surrounding area. Once again,
it was Eclipse lens cleaner to the rescue, and now the mirror is bright and
shiny.
Finally, I revisited the Zuiko lens. This time, with a thicker
coat of Opticlean and a longer curing time, I had no trouble removing
980f the polymer, but there were still a few spots that remained.
These results prompted further discussions with Jim, and we
determined that perhaps I had a bad batch. He sent me a replacement
kit, and on trying it with the Meades, I had much better luck. A thick
coat kept the polymer from tearing on removal, and I had none of the
problems described above.
Finally, I used Opticlean as part of a 3-step process to clean
our 24" mirror. This time, I used a 1" paintbrush to spread the
Opticlean (we bought a pint for this larger area), used a thick coat,
and allowed it to cure for about 2 hours. On this larger optic, with
only one coat, I did have problems with patches that didn't come off.
It was also much easier to see why on the larger optic. If the
thickness of the coat is not controlled pretty well, you get thin spots
which are weaker than the surrounding film, and they tend to tear out.
After speaking with Jim some more, and thinking about what was going on
myself, I have come to the conclusion that 3 thin coats (or even more for
large optics) are much better than one thick coat. Using several thinner
coats tends to even out weak spots in the polymer.
What are my conclusions? Well, in all cases Opticlean removed
the larger gunk and fingerprints perfectly. It also removed some sticky
stuff from one of the pull tabs that I inadvertently got on the Zuiko, so
it is a useful tool in your cleaning supplies. However, it won't remove
particles glued on by condensation, spots caused by condensation, or old
finger prints. Thus, I see Opticlean as part of a two-step process in
cleaning our optics here at the Observatory. I first use Opticlean to
remove all the big stuff that would tend to scratch the optics, then use
Eclipse cleaner and PEC-Pads from Photographic Solutions (www.photosol.com)
to bring the optics to as-new condition. Finally, for optics over about
4-5" in diameter, I suggest you get some of the larger pull tabs from
Dantronix (supposedly "bumper sticker size") and use them as is or cut them
down so that you have the pull tab supporting the film as you remove it. I
think this would have resulted in fewer left-behind spots when I was
cleaning our Meades and the 24". I also wonder if putting a layer of
cheesecloth between to layers of Opticlean would work better than the pull
tabs for removing the cured polymer.
Final word: Is it worth $95 for the kit? My answer is a guarded
"yes". Opticlean will remove big gunk that would tend to cause you to
scratch your optics if cleaning them in a conventional manner, but if you
want pristine optics, you're still going to have to use some sort of lens
cleaner. Based on my experience, the $95 kit will clean an 8" Meade
corrector plate perhaps 6 times for each of the two larger bottles in the
kit. This translates to a *lot* of 35mm camera lenses, and there is a
smaller nail-polish like bottle of Opticlean in the kit that probably
contains sufficient polymer to clean an 8" Meade corrector plate another
3-4 times. If Opticlean saves you from scratching your optics, it is
definitely worth it. With that said, I've been cleaning astronomical
optics and camera lenses for about 15 years, none of it with Opticlean, and
I've seldom scratched or sleeked an optic. As with any method, you have to
be careful when cleaning optics with Opticlean, and understand its
limitations. There are no "magical" cures (no pun intended :).
For more quantitative tests of Opticlean by ESO on their 8-m VLT
mirrors see _Reflecting Telescope Optics Volume 2_ by R.N. Wilson.
Available from Springer-Verlag (www.springer-ny.com in the US). The
gist of the tests was that Opticlean brought the reflectivity of a dirty
mirror back to almost the same as a new coating.
Cheers,
--Lee
(By the way, Step 1 in cleaning big optics for us is a C02 "Snowclean
Machine" which gets rid of any loose dust before Opticlean is used. As
these cost over $1000 without a cylinder of C02, I doubt many camera buffs
will find them worth it).
<<<
C.H.Ling wrote:
> I have ordered a set of Opticlean last year, the price was USD95, as
> it advertised, it can clean hundreds of small lens surfaces. But it is
> very hard to work on, the coating is very difficult to peel off. You
> have to use a sharp point tool to peel off an edge before the whole
> coating can be removed easily. The tape that come with the kit for
> removing the coating does not work well, most of the time it cannot
> lift up the coating and it will leave residual on the lens surface if
>
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