Re: Equipment under rain for 3 hours!


Joe Zeglinski
 

Hi,

A month ago or so, I posted a thread at Digital_Astro group, on something
I accidentally discovered - a really effective way of cleaning fungus from
lenses. I happened to have some Kodak tested and recommended, DSLR CMOS sensor
cleaning solution - Eclipse brand, fairly commonly available in professional
photo stores - and before I tossed out a very badly fungus infested objective
lens, on a very cheap 50 mm department store refractor, I decided to try to
clean it.

Nothing I tried worked - isopropyl, which is commonly used to clean eye
glasses, did clean the lens, but left the "black, pea sized" fungal spot,
absolutely unaffected. Since this was going to definitely be trashed, I
decided to really rub the ISO soaked swab vigorously into the fungus on the
coated objective. Of course, nothing worked, not even scraping it with my
finger nail, to persuade its leaving.

Final shot - I carelessly, and with no due caution, leaked a few drops of
Eclipse onto the fungal spot, and it of coarse streamed across the lens. After
all, I wasn't going to ruin something which now had no value to me, after over
30 years of the scope sitting exposed to moisture in the garage, and later in
the basement. Small wonder that the fungus grew so well!

I briefly turned away from the task, recapping the expensive Eclipse
bottle to prevent loss to evaporation, and in just that half minute or so, I
turned back to the lens, and could not find where the fungus had been. It had
dissolved on its own!

The second shock was that after another couple of minutes, half the
objective lens suddenly clouded over !!!

In despair, at my ruined momentary success, I reasoned that some of this
fluid surely must have gotten between the lenses, since I could not rub the
drops of mist off either side of the objective. With that hope, and in
desperation, I left the lens on the kitchen counter, and when I rechecked it
about an hour later, the lens was perfectly clear, and perfectly clean. I
assume that the quickly evaporating "Methanol" - which is Eclipse's chief (or
possibly only) ingredient, according to their packaging - had rapidly cooled
the space between the lenses by evaporation, condensing the room's (or
basement's) moist air between them, leaving a mist on the inner surfaces. Left
standing a bit, in a warm room, the condensation eventually disappeared on
it's own.

So, my point is that plain but pure, METHONOL, unlike Ethanol, or Ethyl
alcohol, or even commonly used Isopropyl, seems to have a particularly strong
affinity to fungal growth, and might be a good "alcohol" to clean circuit
boards, without leaving a residue, and evaporating quickly, while removing any
lingering fungi under components. Is it safe? Well, Kodak rebrands Eclipse,
specifically for their $6,000 DCS PRO camera's CMOS sensor.

Just a thought - hope it works as well for soaked electronics, as it did for
my lens - and of course, my DSLR CMOS sensor.

Oh yes ... I decided to keep that cheap lens, after that successful
cleaning.
I think the spot might be slightly etched from the fungus eating into the
silicon glass surface, but it is inconspicuous, very hard to find, when I
search for it.

Regards,
Joe

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