Formalin

What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?

Alan Smithee spake thus:

What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?

I don't know; can you use it to kill yourself if your prints turn out
****ty?


--
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(http://counterpunch.org/avnery08032006.html)

In article 3gTEg.410886$iF6.395032@pd7tw2no,
"Alan Smithee" wrote:

What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?

Usually as a color stabilizer.
--
Reality-Is finding that perfect picture
and never looking back.

www.gregblankphoto.com

I'm speculating here, but based on its chemistry formalin
(formaldahyde) might be useful as an emulsion hardener.


Alan Smithee wrote:
What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?

Alan Smithee a écrit :
What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?

http://en.wikipedia.org/wiki/Formalin

It was used in color processes in the final bath as color stabilizer.
It may probably be used in B/W as biocide with a wetting agent.

As it is considered carcinogen, it is replaced now by other chemicals.

Claudio Bonavolta
http://www.bonavolta.ch

In article ,
Claudio Bonavolta writes:

Alan Smithee a écrit :
What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?
....
As it is considered carcinogen, it is replaced now by other chemicals.

Not entrirely. Kodak still sells stabilizer that includes formaldehyde,
and I believe they still sell a few films that require its use for good
long-term storage, although they now recommend a formaldehyde-free final
rinse product for their newer films. I don't know what works best with
most non-Kodak films; some might still require a formaldehyde-containing
stabilizer for best results. I've seen some claims that the newer
processes just move the formaldehyde to other steps, but these have been
raw claims with no substantiation, so I consider them rumor rather than
fact. All told, this is one of the more mysterious parts of color film
processing, at least to me.

--
Rod Smith,
http://www.rodsbooks.com
Author of books on Linux, FreeBSD, and networking

On Thu, 17 Aug 2006 05:37:03 GMT, "Alan Smithee"
wrote:

What is formalin used for in a darkroom. Found a bottle of it. Does it have
any use in black and white photography?

Used to preserve and stabilize dyes in color negative and slide films.
Not useful in B&W processing, AFAIK.
--
Central Maryland Photographer's Guild - http://www.cmpg.org
Strange, Geometrical Hinges - http://sgh.rnovak.net

"Rob Novak" wrote in message
...
On Thu, 17 Aug 2006 05:37:03 GMT, "Alan Smithee"
wrote:

What is formalin used for in a darkroom. Found a bottle of
it. Does it have
any use in black and white photography?

Used to preserve and stabilize dyes in color negative and
slide films.
Not useful in B&W processing, AFAIK.
--
Central Maryland Photographer's Guild -
http://www.cmpg.org
Strange, Geometrical Hinges - http://sgh.rnovak.net

Formalin is an aqueous solution of Formaldehyde, 40% by
volume or 37% by weight. Formalin was formerly used as a
hardener preceding some treatments that significantly
softened emulsions. An example is Kodak Special Hardener
SH-1
Kodak SH-1
Water 500.0 ml
Formalin 10.0 ml
Sodium Carbonate, dessicated 5.0 grams
Water to make 1.0 liter

The crystalized form of Formalin, called Paraformaldehyde,
is used in some lithographic developers but Formalin can
also be used in them. In these developers the Formaldehyde
acts as a source of Hydroxide rather than as a hardener. It
encourages what is called infectious development, which is
desirabel in a lithographic developer but not in standard
developers.
Formaldehyde, in various forms, was and is used as a part
of a final rinse for color films as a dye stabilizer. More
modern formulas have substituted other substances because
Formaldehyde is quite toxic and has an unpleasant odor. It
is still supposed to be a superior stabilizer.


--
---
Richard Knoppow
Los Angeles, CA, USA

In article . net,
"Richard Knoppow" wrote:

because
Formaldehyde is quite toxic and has an unpleasant odor. It
is still supposed to be a superior stabilizer.

Wasn't that one reason alcohol burning engines were stated
to be a problem,...formalin come out the exhaust? Isn't Formalin what
ants spray to kill each other?
--
Reality-Is finding that perfect picture
and never looking back.

www.gregblankphoto.com

"Greg "_"" wrote in message
...
In article . net,
"Richard Knoppow" wrote:

because
Formaldehyde is quite toxic and has an unpleasant odor. It
is still supposed to be a superior stabilizer.

Wasn't that one reason alcohol burning engines were stated
to be a problem,...formalin come out the exhaust? Isn't Formalin what
ants spray to kill each other?

I think you're thinking formic acid. I think they're close but not quite the
same. CH2O (formalin) and CH2O2 (methanoic acid). I think the latter I've
used in bee keeping.