Re: cleaning of filters

Posted by Craig Brideau on
URL: http://confocal-microscopy-list.275.s1.nabble.com/cleaning-of-filters-tp3783387p3783985.html

Another problem with using water is if it is not ultra-pure you will
leave residue behind.  The same is true for using any of the alcohols;
they need to be ultra high purity to avoid leaving behind gunk when
they evaporate.  Fingerprints are remarkably stubborn.  It usually
takes me two or three wipes with methanol to get them off.
Dan's comment about using compressed clean air first is also very
important.  This takes the big particulate off the filter before you
try to wipe it.  That way you are not dragging 'gravel' over the
surface of your optic when you wipe with lens tissue.
Also, Kimwipes are not lens tissue.  Use real lens tissue.

Craig

On Wed, Oct 7, 2009 at 12:20 PM, Dan Osborn <[hidden email]> wrote:

> I would agree with Craig on this.  Whether it is a filter or a dichroic
> mirror, "soft-coated" or "hard-coated" filter, the preferred method is first
> with compressed dry air and perhaps a soft lense cloth.  If that fails to
> remove the smudge(s) a small amount of MeOH, EtOH, or even Acetone will not
> affect the coating if it is not repeated a multitude of times.  Remember,
> "soft-coated" filters are not exposed coatings, so there is either just
> glass on the filter surface, or an AR coating.  "Hard-coated" filters many
> times are exposed but are more resistant to solvent attack.  At least by the
> ones mentioned here.
> Water cleaning can also damage filters and as water does not evaporate as
> quickly as the organics, if any gets behind the filter ring it will hang
> around  longer.
> However, some grime does come off better in aqueous solvents, and it is OK
> to use a good breath of air on the filter surface and either a Qtip or wipe
> to clean it.  A water dampened Qtip or cloth followed by a dry wipe should
> be fine as well.
> -Dan
>
>
>
>
> Dan Osborn
> Product Marketing Manager
>
> Omega Optical, Inc.
> Delta Campus
> Omega Drive
> Brattleboro, VT 05301
> Phone: Direct line: [phone]  or Toll Free: (866)-488-1064
> Fax: [phone]
> Email: [hidden email]
> Web: www.omegafilters.com
>
>
>
>
>
> Celebrating 40 Years
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]] On
> Behalf Of Craig Brideau
> Sent: Wednesday, October 07, 2009 1:53 PM
> To: [hidden email]
> Subject: Re: cleaning of filters
>
> I usually clean coated optics with a single swipe of methanol on a lens
> tissue.  Take a lens tissue and fold it a few times, put a drop or two of
> methanol on it, and do a single swipe across the surface.
> If the fingerprint refuses to come off, refold the tissue you just used to
> expose a clean surface, add another drop of methanol and swipe again.  If
> you are uncertain that your particular coatings are Methanol-compatible then
> test a tiny corner of the optic first!
> Also, make sure to use 'molecular grade' or ultra-high purity methanol, as
> standard stuff contains things that will contaminate your optic.
>
> Craig
>
>
> On Wed, Oct 7, 2009 at 11:42 AM, Carl Boswell <[hidden email]>
> wrote:
>> Hi all,
>> I have some emission filters with dust that will not blow off, and one
>> with an obvious fingerprint, all of which show up as blurry smutz in
>> the image. I appreciate the need for caution when cleaning filters
>> with soft coatings; e.g. no organic solvents, no touching, etc.  But
>> what about a simple soak in dilute soap and water, followed by dH2O
>> rinse?  Or, will a polymerizing cleaners, such as Photonic's First
>> Contact work?  Obviously there is a solvent in this to keep the material
> liquid until applied.
>>
>> Thanks,
>>
>> c
>>
>> Carl A. Boswell, Ph.D.
>> Molecular and Cellular Biology
>> University of Arizona
>> 520-954-7053
>> FAX [phone]
>>
>