RE: Hazards of wet plate collodion ?

MessageDiane,

>From the posts I read, I think Kerik was the only one who explained this
well. I would like to add a few comments however. I just today took 7
students from San Francisco Art Institute through the process for 7 hours so
it is fresh in my mind. BTW, they wouldn't let me use KCN so I had to use
hypo.

Potassium Cyanide (KCN): Let's break down the dangers and strategies:

Dry:
1. Chemical inhalation: when dry, it is highly carcinogenic to the lungs--if
inhaled. Use a simple face mask to make sure you don't inhale any particles.
It is crystalline when dry so not really powder like, but don't risk it. No
need for a big respirator, just a standard surgical mask
2. Chemical absorption: best not to handle without gloves. If you use big
kitchen gloves great. If you use latex, double glove.

Solution: As a fixer, KCN is very dilute. 14gm in 1 liter if my memory
serves me correctly
1. Skin absorption: Best not to handle without gloves. I don't double glove
however when diluted.
2. Solution/fume inhalation: Official guides will tell you to only use if
you have a fume hood, but I use it without a fume hood or even really good
ventilation, but I minimize exposure. KCN SHOULD NOT be used indoors in an
open tray. Generally you fix in an upright wooden box with lid and Plexiglas
liner. You open the lid, lower your plate in with a dipper, cover with lid
again, remove in 1 minute--basically keep the fumes in the box, not in your
darkroom. Since you only work on one image at a time, you'll have to exit
the darkroom after you fix the image and put it in the bath to work on your
next--I just leave my darkroom door open for more air exchange.

Still with me:-) Most people I know are using these same strategies for
their B&W work so I don't see any huge dangers. BUT there is one. If KCN is
mixed with an acid it can produce an odorless poisonous gas--I'm told this
is how it is done in the gas chamber. Bucket of acid and large KCN tablets
are dropped in. I have never validated this however so not sure if it is
true. Technically, your ambrotype developer is an acid. Most wet plate
artists are told that if the two mix they could create a gas. I've been
trying to get to the bottom of this one for months and can't. The two
chemists I've talked to say "officially" it could create a gas, but
"personally" they just don't believe a full bottle of developer dumped
directly into the diluted KCN would cause the gas, but who wants to find
out--don't mix them :-)

Just to be clear. All the written reports I could find about KCN related
deaths in the 19th century literature were due to "accidentally" drinking
it, not a poison gas. So don't drink in the darkroom! I found one report of
a wet plate artist carrying 12lbs of KCN on mules through Yosemite--I wonder
if I could get away with that today.

As Kerik pointed out, the aesthetic qualities that come from using KCN are
at stake. I was distraught all day today looking at images fixed in
hypo--not as bright and the whites are not as creamy--doesn't sound like
much, but I can spot a KCN fixed image from a 100 yards--it makes a big
difference.

Okay, if you use hypo you have two options for "brightening" your
images --no options for obtaining the creamy whites, however. When you
develop a wet plate image you do not dip your plate in a developer, but fill
a shot glass with developer and flow it over the plate--one time use. Before
flowing the developer, you can add a drop or two of your silver nitrate
solution to the shot glass with the developer. The added silver kick will
brighten the image up. Nitric acid will also do this, but it is much more
caustic to manage.

Mark
  -----Original Message-----
  From: Best, Dianne [mailto:dbest@hydro.mb.ca]
  Sent: Monday, August 08, 2005 9:27 AM
  To: alt-photo-process-l@sask.usask.ca
  Subject: Hazards of wet plate collodion ?

  While I am waiting for my books from Coffer and the Ostermans and thinking
about doing wet plate ferrotypes, two things make me nervous:

  #1 using potassium cyanide.

  a) I believe potassium cyanide is a restricted substance in Canada, yes?
What is involved in buying and storing potassium cyanide?

  b) I have seen the damage done by cyanide in the gold mining country of
northern Ontario and I know a little of its history as a medium of
execution - the stuff makes me NERVOUS! It is, from what I understand very
DEADLY. How does one render potassium cyanide solutions safe for disposal?

  c) What kind of handling precautions are required when working with
cyanide solutions?

  d) Is there a safer way to fix collodion images?

  #2 ether

  I understand the wet plate method uses ether. I am a bit more familiar
with ether than cyanide as I have used ether in industrial applications but
ether has two un-nice characteristics - its flammability (explosive vapours)
and its anesthetic nature.

  a) I Would presume that ether is used only out of doors in a well
ventilated area and well removed from sources of ignition?

  I have a lot to learn but I also have an aversion to things that can KILL
me!

  Dianne
Received on Mon Aug 8 21:30:47 2005