Cleaning Solvents

On 19 Aug 2004 00:43:34 GMT, (Jb2269) wrote:

Started cleaning the corrector on my MN-71 and ran into some problems.
Using windex from a fresh spray bottle and cotton balls the debris was easily
removed but after multiple swabs with fresh solvent a spotty film appears as
the surface dries.
At this point I am baffled and start evaporating a bulk sample of Windex
down and to my surprise lots of spots formed and there was some low volatiility
gunk that took ~12 hours to evaporate! BTW during this testing I found a #14
welding glass was the best substrate to find residues, the deposit stands out
clearly.
Now two samples of 91% CVS IPA were evaporated down and they both left
residue but different levels. Almost perfect results were obtained with
distilled water, only a vanishingly small trace of a deposit.
On the basis of this data it seems a precleaning with Windex followed by
distilled water is the way to go. Does this seem reasonable?

Yes. My system of cleaning most coated optics is to use Windex followed by
breath moisture (which is quite pure if you don't breathe so hard that it
becomes disgustingly impure!)

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Why would anyone "experiment" like this on a MN71 ? I guess it's
self evident. Makes me cry.
.....................




Jb2269 wrote:

Started cleaning the corrector on my MN-71 and ran into some problems.
Using windex from a fresh spray bottle and cotton balls the debris was easily
removed but after multiple swabs with fresh solvent a spotty film appears as
the surface dries.
At this point I am baffled and start evaporating a bulk sample of Windex
down and to my surprise lots of spots formed and there was some low volatiility
gunk that took ~12 hours to evaporate! BTW during this testing I found a #14
welding glass was the best substrate to find residues, the deposit stands out
clearly.
Now two samples of 91% CVS IPA were evaporated down and they both left
residue but different levels. Almost perfect results were obtained with
distilled water, only a vanishingly small trace of a deposit.
On the basis of this data it seems a precleaning with Windex followed by
distilled water is the way to go. Does this seem reasonable?
Bill Bambrick
41 N, 73 W, 95 ASL

On 19 Aug 2004 00:43:34 GMT, (Jb2269) wrote:

At this point I am baffled and start evaporating a bulk sample of Windex
down and to my surprise lots of spots formed and there was some low volatiility
gunk that took ~12 hours to evaporate! BTW during this testing I found a #14
welding glass was the best substrate to find residues, the deposit stands out
clearly.

Windex as from the bottle does have some solid or semi-solid
impurities. Filter it through a paper coffee filter paper first into
a clean sealable container.

(HAVRILIAK) wrote in message ...
Windex
down and to my surprise lots of spots formed and there was some low
volatiility
gunk that took ~12 hours to

Based on my results the gunk come from the oils on your skin. Rubber
gloves were the answer for me. You can find a cheap box of gloves in
supermarkets or drug sores. These gloves are of the surgical variety and not
the heavy duty type.

Make sure the gloves are the ones WITHOUT the (talcum?) powder.

Costco recently had a good deal on gloves and I bought some 10 boxes of the
Kimberly-Clark Safeskin PF Preferred Powder-Free Textured Latex Exam Gloves
which I use when cleaning optics and also in my machine shop.

Thanks for the comments. Precautions were taken to prevent he Windex gunk
from being contaminated with skin oils. Perhaps it was a bad day at the
manufacturing plant, I do not know.
The MN-71 corrector was spared all these experiments save the initial
Windex treatment, sorry for the misunderstanding. The results described were
obtained using a sacrificial #14 welding glass filter as the substrate.

Bill Bambrick
41 N, 73 W, 95 ASL