At 7:31 AM +0000 2/1/02, olympus-digest wrote:
>Date: Thu, 31 Jan 2002 19:59:20 -0800
>From: Jim Brokaw <jbrokaw@xxxxxxxxxxx>
>Subject: Re: [OM] Cleaning oily films off of glass; washing wineglasses
>
>on 1/31/02 1:04 PM, Joe Gwinn at joegwinn@xxxxxxxxxxxx wrote:
>
> > Yes. It's very hard to get glass (or china) really clean by hand washing,
> > because one cannot use hot enough water if one uses bare hands. I have had
> > great success wearing medium-thick cotton-lined rubber gloves (Bluettes in
> > the
> > US, available only at hardware stores) and using water at 60 degrees
> > centigrade (140 degrees farenheit), which is scalding hot, hot enough so the
> > grease just vanishes. A hot rinse is required to get all detergent residue
> > off.
> >
> > In the US, many hot water heaters have been turned down to 120 degrees
> > farenheit (49 degrees centigrade) "for safety", making it almost impossible
> > to
> > get glass clean. The traditional setting was 140 degrees farenheit, and
> > restaurants set the temperature to 150 or 160 degrees farenheit, to cut the
> > grease. I've heard of 180-degree hot water sprayers at special stations
> > intended for cleaning deep-fat fryers. With water this hot, one must be
> > very
> > careful.
> >
> > Bosch dishwashers wash and rinse at 140 to 160 degrees farenheit (60 to 72
> > degrees centigrade), depending on the wash cycle chosen. The rinse is often
> > hotter than the wash. The dishwasher heats the water itself, so the inlet
> > temperature has no effect other than slowing things down if the inlet water
> > is
> > cold.
> >
> >
> > I don't know that a lens would survive this kind of treatment, but it works
> > great for 24 0.000000e+00ad wineglasses and the like.
>
>I have a small amount of Waterford glass (different pieces) and the advice I
>got was never wash these pieces in a dishwasher... the harsh soap and high
>heat will leach the glass. I don't think I would risk a $30 glass in a
>dishwasher...
I see I confused the issue above. Nor would I wash Waterford in a dishwasher,
as Waterford glass is generally thick. I usually hand-wash the Reidel
wineglasses, but I once machine-washed them as well, more from cussedness than
necessity. Being thin, Reidels are fairly resistant to thermal shock. The key
is ensuring that they cannot bang around during the machine cycle.
Both Waterford and Reidel use 24 0.000000e+00ad glass, which is mechanically
quite strong. I bet that both factories use industrial dishwashers to clean
their wares before shipment, but if something at the factory breaks it's not a
big disaster for them. Just throw the shards back into the glass furnace,
along with all the other mistakes.
>For oily film or grease on an element I think I would look for a solvent
>suited for oil or grease i.e. some kind of hydrocarbon distillate (naptha?
>toulene? xylene?) although these might be difficult to find and require
>special handling vis-a-vis fumes and skin contact and eye exposure. Remember
>that many chemicals can be absorbed through the skin, with unforeseeable
>consequences, and common rubber gloves might not offer protection for some
>solvents.
Toluol (another name for toluene, actually) is easily available from paint
stores in the US, and I've seen Xylene as well. Ordinary rubber gloves won't
stand up, but (if memory serves) Nitrile Rubber gloves will. There are many
kinds of rubber used for gloves, and one can generally find a glove to resist
any common solvent. Except Methylene Chloride, which will soften just about
any plastic or rubber, given the chance. Glove manufacturers generally publish
a table showing which kinds of gloves will resist which chemicals.
Naptha is also available at paint stores by the gallon, or in small quantities
as Zippo lighter fluid, and may well work. Short exposures to Naptha will not
remove paint or damage plastic, and is also quite useful for removing
self-stick adhesive residue. Mineral spirits are similar to naptha, but
somewhat less aggressive. Gloves are not required for either, unless the usage
is extensive.
At 7:31 AM +0000 2/1/02, olympus-digest wrote:
>Date: Thu, 31 Jan 2002 23:47:10 -0500
>From: "Charles Monroe" <chasmnro@xxxxxxxxxxx>
>Subject: Re: [OM] Cleaning oily films off of glass; washing wineglasses
>
>- ----- Original Message -----
>From: "Jim Brokaw" <
>Subject: Re: [OM] Cleaning oily films off of glass; washing
>wineglasses
><<snip>>
>
> >>> For oily film or grease on an element I think I would look for a solvent
> > suited for oil or grease i.e. some kind of hydrocarbon distillate (naptha?
> > toulene? xylene?) although these might be difficult to find and require
> > special handling vis-a-vis fumes and skin contact and eye exposure.
> > Remember
> > that many chemicals can be absorbed through the skin, with unforeseeable
> > consequences, and common rubber gloves might not offer protection for some
> > solvents.>>>
>
> Easy enough to find in US hardware stores but real nasty stuff.
> Xylene will rot your rubber gloves off in minutes.
Yes, as discussed above.
All this is why I suggested a series of increasingly aggressive solvents. One
starts with alcohols, which are pretty tame, and works one's way up the list
until the film is removed. A mixture of methylene chloride (50%) and methyl
alcohol (50%) will strip just about any oily, cured oily, paint, or plastic
film off of glass without damaging the glass or any anti-reflection coatings.
But it's bad for you, and gloves don't last long, so use lots of Q-Tips (cotton
buds).
An alternative to a Q-Tip is a sterile cotton ball held using a stainless steel
haemostat clamp, which serves as the handle. This is suitable for cleaning
larger optics, but requires care to keep the metal clamp away from the optical
surface. On glass, being touched by the clamp isn't a disaster, but it will
surely scratch the aluminium or silver surface of a first-surface mirror.
Water-based cleaners don't seem that suitable for taking oily films off of lens
surfaces, especially if those lenses are built into a lens assembly of some
sort. That said, Windex (detergent, alcohol, and ammonia in water) is suitable
for getting the whitish film left by some solvents off the glass, after the oil
is gone, and may succeed on lightly-oiled optical surfaces as well; there's no
harm in trying it. One can always resort to the solvents.
Joe Gwinn
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|