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Thread: Chemistry 101

  1. #21

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    silver is getting $31.90 / troy oz ...
    dumping your spent fixer down the drain is the same as dumping
    money down the drain, not to mention in some places it is illegal and punishable by a stiff fine.

    if anyone is interested in a silver magnet
    feel free to contact me for the details ...
    i don't do the "hard-sell" but i will give you the facts
    and help you get set up if you decide to make $$ from your spent fixer ...

    thanks matt!

  2. #22
    Rudeofus's Avatar
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    Quote Originally Posted by Monito View Post
    Never pour water into acid when diluting. Pour acid into water, carefully in no hurry. Reason: the dilution is exothermic (gives out heat) and it is worse to have hot slightly diluted acid boiling up than to have hot slightly acidic water boiling up.
    That's a nice rule but if you read what has been posted here just this week you'll realize that this is just a side issue. If you use KCN as fixer, as has been suggested by someone, just imagine what happens if you decide you also "need" an acidic stop bath.

    It's a good thing that most of the really dangerous chemicals are not sold to ordinary people - otherwise the whole photographic community would have qualified for the Darwin awards many years in succession. I commend Gerald for bringing up this important issue here in this forum and call on all experts who post helpful recipes that they also include some information about the hazards their concoctions can bring with them or at least point out that people without experience and proper facilities should stay away from these mixtures.
    Trying to be the best of whatever I am, even if what I am is no good.

  3. #23
    ChristopherCoy's Avatar
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    So basically,

    -dont drink your fixer
    -dont take a bubble bath with your developer
    -and don't go mixing things in manners the instructions don't tell you to.

    Isn't all of that known as common sense?

  4. #24
    artonpaper's Avatar
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    I tell my students that the standard black and white sink line chemicals are comparable to those found under the kitchen sink. Avoid skin contact, keep your face away from the tray and wash up after a darkroom session. Flush any areas that suffer contact with plenty of water. I then explain that mixing household products also have hazards, such as mixing bleach and ammonia which can be fatal and that certain chemicals used in advanced processes can have a similar reaction, such as ferric cyanide and acids. When working with chemicals always proceed with caution.

  5. #25
    K-G
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    Quote Originally Posted by ChristopherCoy View Post
    So basically,

    -dont drink your fixer
    -dont take a bubble bath with your developer
    -and don't go mixing things in manners the instructions don't tell you to.

    Isn't all of that known as common sense?
    Correct , but the total amount of common sense seems to be shrinking at the same pace as the polar caps do.

    Karl-Gustaf
    Karl-Gustaf Hellqvist

    www.heliochroma.com

  6. #26

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    Quote Originally Posted by ChristopherCoy View Post
    So basically,

    -dont drink your fixer
    -dont take a bubble bath with your developer
    -and don't go mixing things in manners the instructions don't tell you to.

    Isn't all of that known as common sense?
    You'd think so, but there's a certain DIY ethic that legitimately clashes with that third bullet point. I mean, the instructions don't tell you to mix coffee and washing soda to make developer, either, but it's pretty well established that nothing bad happens as long as you don't drink the result. So a more realistic guideline might be "don't go mixing things unless you know what to expect", but that's also easier for a reasonable person to mess up ("well, I *thought* I knew!").

    By the way, the mnemonic I learned in chemistry class was "do what you oughter: add acid to water", which is goofy but memorable.

    I like the idea of a sticky "elementary darkroom chemical safety" document.

    -NT
    Nathan Tenny
    San Diego, CA, USA

    The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
    -The Little Technical Library, _Developing, Printing, And Enlarging_

  7. #27

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    Quote Originally Posted by ChristopherCoy View Post
    So basically,

    -dont drink your fixer
    -dont take a bubble bath with your developer
    -and don't go mixing things in manners the instructions don't tell you to.

    Isn't all of that known as common sense?
    Let me add that it is wise to use eye protection when diluting concentrates such as developer and stop bath. Most people have no idea of what to do if a chemical should get in the eyes.

    Darkroom chemicals are not innocuous and many are dangerous if handled incorrectly. Always read the warnings on the label.

    The main problem with common sense is that it is not at all common!
    Last edited by Gerald C Koch; 09-29-2011 at 02:16 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  8. #28
    Vaughn's Avatar
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    It is nice working for a university with a friendly Chemistry Dept. I have a pound of Potassium clorate that is one semi-solid chunk. When I needed a small amount, I gave a call over to the Chemistry folks to 1) make sure that its age would not be a factor and 2) if it was safe to knock off a chunk. I was told it would be fine, and not to use too big of a hammer.

    Kodak Rapid Fixer Part B (hardener) will eat thru your clothes nicely -- lost a pair of jeans that way years ago.
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  9. #29
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    Wait wait wait.....I thought that hypo-clear was great for cleaning my contacts, and pyro is a great base for my Pyro Hot Sauce (copyright pending). I think you're all just being sissy-nannys.
    K.S. Klain

  10. #30
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    Quote Originally Posted by K-G View Post
    Correct , but the total amount of common sense seems to be shrinking at the same pace as the polar caps do.

    Karl-Gustaf
    Nah. I think common sense is receding far faster than the ice caps. Have you seen what's going on in Washington lately? How much common sense can be left?
    Last edited by michaelbsc; 09-29-2011 at 05:53 PM. Click to view previous post history.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

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