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  1. #21

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    Bob are you talking of low pressure sodium SOX lighting as a safe light and what wattage do you use please? is 35w sufficient in a 7x10 foot darkroom?
    I ask as high pressure sodium SON lighting gives a white ish light rather than orange.
    A lot of public authorities are moveing to SON street lighting for its better light output hence fewer lights and cost saveings so that low pressure SOX lamps will become harder to get and more expensive as time goes on.
    It may be possible to get an old 35 SOX lantern from the local council when they upgrade their lights to SON ones.
    Regards Paul.

  2. #22
    Bob F.'s Avatar
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    Quote Originally Posted by Paul. View Post
    Bob are you talking of low pressure sodium SOX lighting as a safe light and what wattage do you use please? is 35w sufficient in a 7x10 foot darkroom?
    I ask as high pressure sodium SON lighting gives a white ish light rather than orange.
    A lot of public authorities are moveing to SON street lighting for its better light output hence fewer lights and cost saveings so that low pressure SOX lamps will become harder to get and more expensive as time goes on.
    It may be possible to get an old 35 SOX lantern from the local council when they upgrade their lights to SON ones.
    Regards Paul.
    Nope, sorry: I'm talking about ones made specifically for the Darkroom such as the Duka 50 and Thomas in the US. I have a Duka 50 and replacing the lamp would cost me over 120 GBP - call it $250 US... Big surprise: I made my own LED lamps instead!

    Cheers, Bob.

  3. #23
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    Quote Originally Posted by Vaughn View Post
    More important than ventilation air exchange is the location of the intake and exhaust vents.

    If your head is in the path of the exiting fumes, then one might as well not have ventilation. Ideally, one has the fumes sucked up right above or behind the trays, and fresh air comes in pass one's head.

    I silver printed for 15 years in a darkroom with poor ventilation -- no problem at all. Some others (we did a survey...we have 150 students/semester) experienced headaches, etc in a relatively short period of time. Some student (and myself) can just about bathe in Dektol -- other students' hand will show signs of contact dermatitis the first time they touch Dektol. One can never tell.

    After 5 years of platinum/palladium printing I have developed a very bad reaction to pd/pt dust.

    If one uses an acid stop bath and/or fixer...and has asthma, then excellent ventilation is a must.

    Vaughn
    In a classroom setting I would over emphasize safe darkroom practices. Always glove up and wear a respirator when ever applicable. When mixing dry chemicals I would shut the fans off and wear a respirator. I always run hot water in the sink to bring the humidity up before I ever get the palladium and ferric oxalate out of the cabinet. Or any of the dry chemicals that I'm working with. This will help settle any dust and particles in the air. I always wear surgical gloves but then again I have an endless supply of them. Just remember to turn the fans back on once you get everything into solution. You can always make the MSDS required reading and take the fun out of the photography class too. (just joking) I've seen a bad case of dermatitis from a metol reaction and it is not a pretty site. And once you react you will never be able to use that developer again. If you're having bad reactions to palladium I would suggest all the above. Respirator, gloves, long sleeves, maybe even a baseball hat/ hair net. It is virtually impossible to weigh and mix palladium powder without some getting airborn so a full-face clear shield would probably be a good idea also. I know this all sounds like a lot to be able to work and be comfortable at the same time. But it's like wearing a seat belt, once you are use to it you'd be surprised how tolerable it is. You're right on about the direction of air flow. You definitly don't want to pull the fumes into your face. Most of the darkroom fans you buy come with a pretty good diagram showing the proper ventilation flow and how to rig your exhaust fans and passive intakes. There's probably numerous diagrams and designs in books and on the internet about darkroom design. If handled properly any of the chemicals we use can be used safely. The only one that still makes me a little nervous is the potassium cyanide used for fixing wet plate. That's one where a mistake could prove costly. So the nerves seem to make my focus a little sharper when handling it.

  4. #24

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    13 hours! Do you wear a catheter?

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