how to handle bromine

[brunoinbelgium]

hello everyone
it has been a year i have been shooting and developping dags whenever the Belgium weather gave enough sun
– Marc Kereun in France taught me how to get started with iodine and mercury : i really recommend his coaching
and as i want to step up in the technique , i would like to begin to sensitize with bromine in order to make portaits
i did get a few milliliters of pure bromine and i build a box ( the same as for iodine )but the 2 times i tried , i just suffocated with the fumes even though i have a professional chemistry hood working and exhausting everything out of the room
so my question is when we need to handle bromine either diluted in water or in lime ,how is it possible to keep the red vapors confined at all time and keep safe ?
i have made a fume box (the drawer type ) with a pvc sheet pressed tight on a pyrex but there are always leaks and when i put a plate to react , the few seconds i take it away to check the progression , make the vapor leak and make the whole room irritating to breathe
i do have a chemistry degree so i realize the dangers to avoid and this is why i ask you all more experienced people what solutions are possible
thanks in advance
Bruno

[jgmotamedi]

I don’t understand how you could have a fume hood which is “working and exhausting everything out of the room” and still smell the fumes. Could you explain this? With a properly functioning fume hood nothing should escape.

Is the bromine not inside the hood?
Is the hood not sucking properly? Did you measure with an vaneometer?
Is the hood leaking fumes back into the room? Did you test with a smoke bomb?
Perhaps the fumes are being sucked back into the room because the hood doesn’t exhaust it far enough away? (another reason to test with a smoke bomb)

Also, if your room smells every time you put in a slide, I would say that your bromine is way too strong and your fuming box is not well made. Note also that PVC is not a good material for bromine. PTFE (Teflon) or glass is much better.

Finally, if your bromine fumes are escaping, perhaps mercury is too… Of course, you can’t smell mercury.

[brunoinbelgium]

Hi
thank you for your reaction -it helped me to figure out where the problem is
the hood is not a sliding one and as i need to work in it , it is a flipping up plexyglass pane opening too wide
i will try to get a smoke bomb to test it (do you have an address where to get this ?)
obviously what is working for iodine must be done much tighter for bromine and i will take some time to rebuild a fuming box using ptfe sheet
could you indicate me what dilution of bromine is working best ? and what is the less aggressive lime or water ?
for the mercury , i use a vacuum pump and a dessicator so i think i am on the safe side
thanks again
Bruno

[Mike Robinson]

Bromine in water according to the old manuals is 1 drop in 40 of water.

lime (calcium hydroxide) should be a medium pink through and through. see picture “bromine in lime”

I find silica gel 6/16 mesh the best medium for controlling bromine. I call it Robinson’s Quick.

I discovered this in 2003 and have been using it ever since. Bromine in silica gel should be yellow.
see picture stock/vs/working. When bromine works too slow, add a small amount of stock.

the picture shows how the silica gel is charged.

Mike Robinson

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[photolytic]

Thanks Mike – Excellent post!

Back to Bruno.

I assume from your mention of a vacuum pump that you are using vacuum cold mercury developement. 

Your feed back is important. How is that working for you?

What vacuum, temperature and times work best for you?

Do you vent the fumes from your vacuum pump outdoors? 

Are you planning to attend the Daguerreian Society meeting in France in October?

 

 

[jgmotamedi]

I am still not sure why your hood is not working properly. Is the opening too big for the pull of the fan when you open the acrylic door? A professionally built fume-hood should have a motor with more than enough pull (>100 feet per minute) to keep the fumes inside. Did you replace the motor? Maybe you have too much pipe?

Seriously, it is time to stop and solve this before you do anything more. You are putting your health in danger. There is no reason you should ever smell bromine.

Buy a vaneometer. I dont know where to buy one in the EU.

I don’t know where to buy a smokebomb, as these are considered fireworks and aren’t usually shipped. You can make one out of sugar and potassium nitrate, look on the web for instructions, but be careful as these spit a lot of sparks.

[brunoinbelgium]

hello everyone
i am very grateful for all the messages and I appreciate very much your support:

For Mike : MANY thanks to show a better way to handle bromine – i am ordering silicagel asap and will try that method as i get a new tighter fuming box build ( with ptfe this time)

for Photolytic : thanks for your attention and yes i am using a vacuum cold mercury method
the temperature is around 15°C to 18°c and a 5 hours time is common – i check with a red light (rubylith around a bulb) till i think it is enough
the pump i use has an outlet ballon which i filled up with zinc and copper scraps so the remaining mercury vapor should react with these and the outlet last pipe is in the fume hood
i was not aware of a Daguerreian Society meeting in France please let me know the details and i will work my schedule
i was not a member so far but i would happily do so if they are organizing events on this side of the ocean

for Jgmotamedi : you are right about i have to solve the problems and i am rethinking about other way to handle bromine safely : that is why i addressed the first help message to the forum .I did try a way that i realize is not working and i wanted to know how other fellows were doing it
thank you very much again for your reaction and be sure i do as much possible to stay on the safe side
Bruno

[pruts]

Hello ,
Nice to hear from a collegue working in Belgium.

Marc Gommé

[Author]

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