cold mercury development and safety rules

[Bakody]

Hi,

My name is Máté Bakody. I’m new in the world of daguerreotype. At the moment I’m studying how to make Becquerel and Mercury daguerreotype. Before I will make the first one, I would like to make sure about my, others and the environment safety.

So I would like to ask a few question in this topic and please correct me if something missing:

-Iodine: proper gas mask with iodine/ halogen filter + glasses + gloves

When I’m not using it, I need to put it back in to the iodine container.

-Bromine: proper gas mask with bromine/ halogen filter + glasses + gloves

What to do with it when I’m not using it? Just a few drops and most of the bromine will be vapour.

Am I need to clean iodine, bromine fuming box after each use?

-Mercury: proper gas mask and fume hood!!! At the moment fume hood would be expensive for me. Because of this I started to refuse the ideal to make mercury daguerreotype, when I found “WARMING UP TO COLD MERCURY” in the resources. John R. Hurlock was using vacuum desiccator. I think a vacuum desiccator will be less expensive then a fume hood.

Are daguerreotypes have the same tones like in traditional mercury development?

I think, I still need to wear a proper gas mask with mercury filter when I start the process. But what about when the process finished and need to take out the daguerreotype. Is the air more toxic then before?

And when the vacuum pump is working? How to handle the air which coming out from the pump?

I saw somewhere, that over 20 C mercury vapour in the air will highly increase. So if I keep the temperature between 15 and 20 C and wear gas mask, am I in safe? Which one is safer: vacuum desiccator or fume hood?

The vapour in the air will go out in the garden where vegetables, fruits are. Who far I need to be from them?

I’m Hungarian. Sorry if my English is incorrect in a few places.

Thank you.

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

Hi Máté,

Welcome to the confusing world of modern Daguerreotypy.

I say confusing because there are many ways to make Dag and even more rules about safety. Since you are just beginning, I would suggest that you first read more of the posts and articles in the resources section of this website to give you a running start.

First the Iodine: In the proper quantities, an essential element in the human diet to prevent goiter. Iodine tablets are widely used in Africa to disinfect polluted water. Works like chlorine to prevent cholera only far safer to handle.

The generally accepted method of handling Iodine is to keep it in your well sealed fuming box between uses. Transferring it in and out of the box is messy, and unless there is some risqué the box will break while you are transporting it, unnecessary.

If you have a good fuming box you will not smell or otherwise be exposed to iodine fumes while you are fuming plates.

Second Bromine: Bromine is now replacing chlorine to disinfect swimming pools. It is also present, as bromide salts, in the air above the Dead Sea, which many tourists visit for their health.

Daguerreotypists usually mix the liquid bromine with calcium hydroxide, silica gel or even water in a well ventilated area or better yet, outside. Then put this mixture in your fuming box and leave it there. Glasses and gloves are advisable and mask may be needed during mixing unless the ventilation is extremely good.

As with Iodine, the odor or exposure to bromine from a well constructed fuming box should be negligable during plate fuming.

Cold Mercury: Unlike the halogens, the once widely used medical applications of mercury for everything from skin rashes to syphilis are now in the dustbin of history.

First, familiarize yourself with the use of glass vacuum desiccators. You only have to pump out the air once each time you develop a plate. When the dessicator is sealed, the vacuum stays constant until you let the air back in.

The air you suck out contains the same low level of mercury as the air remaining in the dessicator, not more. If you are at all concerned about your fruits and vegetables, I recommend passing the discharged air from the pump through a coil of copper tubing or a bed of mossy zinc. The amount of discharge will be far less than from a fume hood which your neighbors should appreciate.

To develop at plate, I recommend a temperature of 20c and a vacuum of 50 to 75 torr for 2 hours.

Good Luck,

John Hurlock

[Bakody]

Hi John,

Thank you so much for your answer. I will need a few more month to make my first daguerreotype. Until that I keep studying.

I will post the first results in this forum.

Máté

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[Bakody]

Hi,

Which one do you use? Bromine or bromine water. Maybe bromine water is safer to use.?

If I wont use bromine, is anything will change in the final picture, like tonality? (I know, that need to use it because of shorter exposure time, but what about tones?)

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

I use bromine mixed with calcium hydroxide.

Bromine water is sometimes the only form of bromine available in some countries.

but water in any form in the fuming box can cause blue tones on the plate.

Bromine fuming not only makes the plates 60 times more sensitive, but when used in the proper ratio with iodine, it can also reduce excess contrast and solarization. Too much bromine can cause fog.

[newone2010]

Hi,

Glad to see new practitioner as me.Making dags is really hard work.I tried hard to get good results but failed,but I will keep trying.

Hope to see your results soon.

best,

Li

[Bakody]

Hi Li,

I always check your posts. I can study a lot from them.

Máté

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[Bakody]

Dear John,

Can you post here a picture about your vacuum desiccator? What kind of vacuum pump do you have?

Thank you.

Máté

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

I use a 2-stage rotary vane vacuum pump commonly used to evacuate cooling systems prior to adding new refrigerant.

http://cgi.ebay.com/JB-DV-142N-5-CFM-2-STAGE-1-2HP-VACUUM-PUMP-/290562964099?pt=BI_Pumps&hash=item43a6e6fa83

 

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[Bakody]

Thank you!

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[Bakody]

Hi!

I wont have money to buy fume hood, so I want to use gas mask for my protection. Is it enough?

Is anyone else using just gas mask and no fume hood?

How can I know, that I need to change the filter in the mask? or how often I need to change it?

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[christian_rice]

Here’s a web page for 3M cartridges to protect from mercury vapor and chlorine gas. It has some detailed instructions. I just googled “respirator with mercury filters.”

Click to access mediawebserver

Note that the cartridge says it is only useful up to certain concentrations–above which you are in trouble. If you don’t have adequate means of keeping mercury levels below the required level, wandering into a space full of mercury will be bad for you.

You can make a fume hood out of a large plastic storage container and a decent exhaust fan. I’m sure something passable could be done cheaper than buying a professional hood. I’m planning to build my own from raw materials–probably acrylic sheets, but I, like you, am open to suggestion.

[Bakody]

Thank you for your reply.

Yes, it’s a good ideal to build a fume hood (without filter) and it wont be expensive. On the internet I found some articles about this.

I hope my neighbours and my family will be in safety as well…

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[Dafna Gazit]

Hello all,

I am also about to make my first Mercury Daguerreotype with vacuum desiccator!

I have pure bromine. How do I use it for sensitizing the iodized plate?

Photolytic, you mentioned that “Daguerreotypists usually mix the liquid bromine with calcium hydroxide”, what amount of calcium hydroxide do I have to use? Do I have to add anything else for the Bromine? Can I make a re-use of it for later Dags?

Can I use the Bromine without the Calcium Hydroxide?

Another question:

You mentioned above that you use vacuum of 50 to 75 torr for 2 hours.

In his article “WARMING UP TO COLD MERCURY”, John R. Hurlock writes about “25 mm Hg” for 24 hours. I am confused of the differences between units of vacuum measurements. Is “”25 mm Hg” is the same meaning for 25 torr?

Thank you

[greg7mdp]

Hi Dafna,

Yes, mm Hg and torr are about the same, you can use them interchangeably. It is reassuring that Photolytic agrees with John Hurlock, since they are one and the same person, a master daguerreotypist living near Chicago, ILL.

About the bromine, you need to (carefully, wearing safety glasses and other protection, preferably outdoors) mix a few drops with a small quantity of calcium hydroxyde (200g for example, more if you have a large box), and put the powder at the bottom of the bromine box. The resulting powder should have a light orange color. Be quick because the bromine evaporates quickly. You can reuse it many times if your bromine box doesn’t leak. Next time check the color of powder. If it white all the bromine is gone and you will have to add some more.

Good luck,

greg

PS: From wikipedia: Torricelli attracted considerable attention when he demonstrated the first mercury barometer to the general public. He is credited with giving the first modern explanation of atmospheric pressure. Scientists at the time were familiar with small fluctuations in height that occurred in barometers. When these fluctuations were explained as a manifestation of changes in atmospheric pressure, the science of meteorology was born.

Over time, 760 millimetres of mercury came to be regarded as the standard atmospheric pressure. In honour of Torricelli, the torr was defined as a unit of pressure equal to one millimetre of mercury.

[Dafna Gazit]

Greg,

Thank you so much for the information and for opening my eyes about the true identity of Photolytic!

[photolytic]

HI Dafna,

Yes, I am John Hurlock and I live in my Dagcave with my faithful four footed sidekicks Squeaky, Boadicea, and Lisel. No great secret here since I signed my name in the second post of this topic but thanks to Gregory for clearing up any remaining confusion.

I sometimes use the term torr which is a measure of absolute pressure in mm of mercury commonly found in scientific articles, rather than the term mm of vacuum since the latter requires some prior knowledge that the standard atmospheric pressure here on Earth is 760mm of mercury. Those of you who have been following the recent presidential debates can appreciate the confusion among future Daguerreotypists living on moon base Gingrich.

The quotation “24hours at 25 torr” is a bit misleading, since only 1 hour at 25torr is enough to develop a Dag at 20C.

Gregory is correct in that only a few drops (0.2ml or a little over half a gram) of liquid bromine in 200 grams of calcium hydroxide is enough to turn it a light orange color, but unless your fuming box is sealed very tightly, you may need to replenish this weekly to maintain constant fuming times.

Also don’t store your bromine and/or iodine fuming boxes in the same hood where you are developing Dags as even a small amount of halogen is enough to erase the latent image of a Dag. Yet another reason to rely on a well sealed fuming box rather than a hood for long term storage of fuming mixtures.

John Hurlock

[Dafna Gazit]

Hi John,

Thank you for clearing up a few things.

I will upload and share with you guys my next (and first) cold mercury developed Dag

🙂

Dafna

 

[Dafna Gazit]

Hello again

I have this Gauge connected to my vacuum pump, but I am not sure how to read it for my cold mercury development… maybe one of you can help? It is the only gauge that the experts here could find for this purpose. In the second photo you can see that I marked the units that I think I will need to use, am I right?

thanks

Dafna

 

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[photolytic]

Dafna,

You are right.

The units on your gage are 0 to -760mm (-29.92inches) of mercury which is a “perfect” vacuum.

A vacuum of -27in or -658mmHg is best for vacuum cold mercury development.

To use the gage turn on your vacuum pump and open the ball valve below the tee.

Wait until the gage needle rotates counter-clockwise almost to the -700mm position.

Then while the ball valve is still open and the pump still running, close the valve on the top of the vacuum desiccator (not shown) and disconnect the rubber tubing from the desiccator so you can place it in a large box away from the light during development of the Dag.

At this point you may turn off the pump.

Digital vacuum gages are also available.

They are somewhat easier to read.

[Dafna Gazit]

… so if I understand you correctly than I was’nt right and I should use the paremeters like I marked in the photo below….right?

 

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[photolytic]

Yes, the vacuum you need is on the left, inside your red circle. Any vacuum higher than 685mmhg will also work but timing development is more difficult since the air pressure needs to be restored slowly to avoid spraying dust or drops of Hg on the Dag. The pressure restoration time depends upon the volume of the desiccator. Always face the Dag away from the desiccator inlet to minimize Hg droplet spots.

[Dafna Gazit]

Thank you!

Wish me luck!

🙂

 

[Dafna Gazit]

One more question:

How much mercury should I put inside the container?

and, do I need to filter the mercury in order to clean it from dust and other foreign substances that may be in it?

[photolytic]

For wholeplates, use enough mercury to cover the bottom of a 5 to 10cm dish. The dish should be deep enough (1cm) to prevent the mercury from sloshing out when you move the desiccator. To prevent the dish from sliding around, nest the dish in a thin layer of silica gel on the bottom of the desiccator.

If your mercury has a grey oxide coating on the surface, filter it though a funnel made from a small (5cm) circle of filter paper folded in quarters. Poke several pinholes in the bottom of the funnel to allow the mercury to flow through. The oxide particles will stick to the sides of the paper funnel. To faciliate flow of the last of the mercury at the bottom of the funnel, gently pick up the funnel wearing latex gloves, fold the top of the funnel to close the opening, and squeeze from the top until the last drop of the mercury is filtered. If there is still oxide left in the mercury, repeat the filtration with a fresh paper funnel.

To prevent lampblack or other polishing residue from accumulating in the mercury, wipe the back of your Dag plates with a tissue before fuming.

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