[jgmotamedi]

This past weekend I tried to synthesize bromine using the NaBr, muriatic acid, and calcium hypochloride method mentioned in my first post. It clearly produced bromine water as well as a few mls of bromine on the bottom of the flask, but it was not a clean reaction. The calcium hypochloride did not dissolve well into water, and reacted with the muriatic acid to produce a good amount of white precipate, perhaps CaCl? Anyhow, I will abandon this route as the precipitate is too difficult to effectively filter, and I realize now that removing water from bromine is not as easy as I thought. I really don’t want to distill it nor buy a distillation set. I may try to bubble Cl gas through a saturated NaBr solution this weekend, if I can figure out an effective way of producing the gas in one beaker and then bubbling it through another solution.

[jgmotamedi]

I have found the difference between Becquerel developed plates and traditional I/Br/Hg plates to be pretty close to a 2.5 stops (10x). So, to follow Mike’s example, a 3 second I/Br/Hg plate becomes a 30 second Becquerel plate. This basically matches with my very limited use of I/Hg plates, which I have found to be about 5x slower (<2 stops) than Becquerel.

[jgmotamedi]

Indeed, lenses are made of glass and filter out significant portions of UV light. It should be a problem, yet there was an article somewhere (?) about the use of a special Zeiss UV-passing lens with Daguerreotypes. The upshot was, oddly, that this special quartz crystal lens didn’t significantly decrease exposures with Daguerreotypes.

[jgmotamedi]

Oh, never mind, I was just being foolish. Windowpane glass will filter out enough of the UV light so as not to cause any damage. After all, you can’t really get a sunburn through a window can you?

[jgmotamedi]

Ah, I that makes sense. The blue light would certainly decrease squinting, but I wonder if the blue glass could increase the likelihood of Kliegarcsnowdag eye, as it might fool the brain into thinking there was less light than there actually was, and open up the eye’s iris–much like during a solar eclipse.

Or am I being silly?

[jgmotamedi]

I have read also that the 19th century Daguerreian studios had blue tinted windows, but it seems sort of asinine to me. After all, blue glass would just filter out some of the non-blue light, it wouldn’t increase the blue or UV light and certainly wouldn’t decrease exposure time. Bad 19th century science? Or perhaps it aided the operators judging exposure since the irrelevant light was partially reduced?

Anyhow, Klieg eye is the same thing as snow blindness and was caused by carbon arc lights, which are not available any longer. However, a number of light sources, notably high wattage mercury or metal halide, and pulsed xenon do produce enough UV to cause eye or skin damage so one should be cautious in selecting and using light sources.

[jgmotamedi]

Thanks, I have heard about the TechShop and will look into it.

[jgmotamedi]

I built two sets of lights using four (eight total) Phillips florescent 55W 5500K florescent bulbs (the same ones which some of the more expensive photo lights like Gyoury use) which put out a decent amount of UV from an aquarium supply. I could have used 10,000K “black light” bulbs, but I also use these for copy work. Another option would be to buy two or three 750watt metal halide bulbs, ballasts, and reflectors from an “indoor garden” store. These are not terribly expensive and should put out lots of UV.

In an aside a few weeks ago I stripped some parts off a high end 20×24 graphic arts camera which was on its way to the dump. It had an interesting light system which I salvaged but have not yet tried. It uses four 1500 watt pulsed Xenon lights which should put out LOTS of UV light, but may actually be dangerous.

[jgmotamedi]

Andy, is the Becquerel or traditional?

Not that it matters much, as it has been my experience that the effect of bright lights before the final iodine fuming is negligible. Once upon a time I compared a 15 watt compact florescent bulb about 5 feet away from the plate and an 8 watt (?) tungsten night light, and neither produced a perceptible difference in base fog, using the densitometer function on a scanner to judge. From them on I have used pretty bright lights while inspecting. There was an article by John Hurlock in the Daguerreian Annual about the effects of light between fumings, and as I recall (I read it some time back, so perhaps I remember incorrectly) one take-home-point was that a fair dose of light between the bromine and the final iodine increases plate sensitivity.

[jgmotamedi]

I too would worry about the sulfur in the solution and prefer the you-tube solution you posted which uses KI with H2O2 and HCl. Like the bromine synthesis above, this would replace the I- in KI solution with Cl-, and precipitate out the I2. I guess that this would produce KI, I2, Cl2, and water. Since I2 has limited solubility in water, you should be able to filter it, and wash a few times with distilled water then filter and dry. You could also sublimate it to further purify it, but I am not sure that would be necessary. One warning however, that H2O2 plus any sort of acid makes a very exothermic (HOT!) reaction which could be dangerous. Using concentrated HCl or H202 could be dangerous, so use diluted chemicals or easier yet, use hardware store muriatic acid (~30% HCl) and the 3% (?) hydrogen peroxide from a drug store. In any case, be absolutely sure that you never directly mix the hydrogen peroxide with the acid.

A big caveat, I also am not a chemist…. Are there any chemists on board? I usually ask a friend to go over reactions with me.

[jgmotamedi]

Hi Brenton, nice to meet again! I have never used bromine water, although I suppose there is no reason I couldn’t try.

It seems that nearly anything can be used to make meth. In any case, I will also look into making iodine, although for the moment I have more than enough. Did you have a method in mind Andy?

For what ever it is worth, I stopped by Alaskan Copper and Brass this afternoon (a major manufacturer and distributor of metals, at least on the left coast of the US), looking into new sources of copper. While they didn’t have any of the old mirror finish copper I used to use, their prices for a 36″x96″ sheet of .04″ copper with a milled finish was $240, and 18 gauge brass was $175. That seems pretty cheap, and would make quite a few plates. They had remnants too, which were very cheap, but in odd sizes and a bit banged up. Of course, the problem is they won’t cut to size (anybody know a cheap source of plate guillotines?) and the milled finish will take a lot of work to get to a nice polish.

[jgmotamedi]

Thanks for the responses.

Ken, I didn’t know you were in Seattle. Although you don’t know it, I am indebted to you. Your 1977 manual–along with Levi Hill, SD Humphrey, and advice from Irv–was my guide to mercury developed plates and remains an important reference for me. So belated thanks. I get up to Seattle with some frequency for work, so perhaps we can meet there sometime.

The idea is that most of the bromine, once it saturates the K/NaBr solution, will settle below the solution. I assume there will be some loss to vapor, but I am guessing that the pressure of the solution will hold most of the bromine in liquid form.

Andy, I don’t know about how pure the bromine must be. Does a bit of water in it change its reactivity? According to a few posts on various online forum you can remove most of the water by stirring in some concentrated sulfuric acid. The acid doesn’t react with the bromine and absorbs the water. Of course, an easier method might be to simply distill the bromine, which if done at a low enough temperature should remove the water and any other impurities. I haven’t thought about iodine, since it is still pretty easy to buy. Mercury also seems to be relatively easy to purchase, but I have enough of that to last a lifetime (and cut my lifetime significantly shorter).

Before I do this, does anyone have a good source for bromine?

best regards

jason greenberg motamedi

[jgmotamedi]

Greetings all.

I know some of you and know of many of you. I have been making Daguerreotypes–both Becquerel and traditional–on and off since 2001. However, I haven’t made a plate for more than a year after moving, because my darkroom and studio came second to a functional kitchen and bathroom. However, two days ago I finally hooked and tested my fume hood, and I am just about ready to go.

It is wonderful that this forum exists. Even a few years ago I had to bug Irv and Jerry to get my questions answered. They were always gracious and quick with their answers, but it is so much nicer to share with a whole community than bother one person. I also notice in the short time that I have been gone that it has gotten harder to find supplies. Rembrandt graphic, where I used to buy copper seems to be gone, and the local lab supply house quoted me $375 for 100ml of bromine! Anyhow, I see lots of links here to new suppliers, which I will have to investigate.

In the meanwhile, I look forward to exploring the forums.

jason greenberg motamedi

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