[jgmotamedi]

John,

The temperature in the fuming area is in my basement and is pretty consistent through the year, about 66F/19C. In my previous darkroom there was a lot more variation. My developing area (in a converted garage) is not consistent, although my mercury pot is electronically controlled, and keeps the temperature very accurate, usually within .5 degrees Celsius.

I will certainly take my 2nd iodine time down to increase the contrast and reduce my mercury temperature to increase control, however I don’t understand the second part. Yellow-magenta after the 1st iodine or the bromine yields the highest sensitivity?

Sorry for the typo earlier; I am using one strobe head with 9600w/s at about 32″/81cm from the subject.

jason

[jgmotamedi]

Auric Chloride (AKA Gold III Chloride or AuCl3) is what I have always used.

[jgmotamedi]

Right you are! I will create another topic.

[jgmotamedi]

I will note for the record that I used a Speedotron 105 four cable head in a 22″ “Beauty Dish” reflector with a 4800w/s and a 2400w/s box. The rim of the reflector was about 32″ from subject, and was placed above and to the right of the camera.

I would love to hear about other people’s set-ups (Rob?), but am more concerned right now about my plate. Any comments on that?

[jgmotamedi]

I love the composition BTW.

Thanks for the compliment Andy, but composition with a 4 year old? Negotiation perhaps.

Anyhow the reciprocity question is a good one, there does not seem to be much on the other end (long) of the exposure spectrum, but that doesn’t mean that there isn’t on short exposures. For what ever it is worth, these exposures are comparatively long for strobes–around 1/400 of a second according to Speedotron.

[jgmotamedi]

The polishing was a rough machine polish only; no hand buffing at all. Not my usual routine. So, as much as possible, please ignore the polish marks.

Although it does not show in the posted scan (you have view it at full resolution by downloading), the shadows are “misted” and the whole plate is weak. Normally I would guess that the misting is due to over-development, but perhaps the reason it is “weak” and difficult to see is because it is under-developed. Or am I second guessing myself?

[jgmotamedi]

Mina at 7200 w/s

 

I have been rather occupied with life and a blown motor on my fumehood. Anyhow, although it was not part of the “plan”, I was given a huge collection of Speedotron strobe heads, boxes, stands, et cetera. So, rather than cope with weak Oregon light, I decided to quickly check to see if there was enough power in the equipment to light a dag. Sure enough, 7200 w/s on one head was enough to expose a plate at f/2.8.

 

My daughter agreed to sit, although complained about the flash afterward. To make up for it, I allowed her to push the button while I sat in the chair. It wasn’t as bad as the descriptions I have heard of Jerry Spagnoli’s set-up–burned hair and all of that–but it does make a very loud POP and you see spots for a minute or so. I think Jerry told me he used 9600 w/s at f3.5, but I am not sure.

 

Anyhow, as you can see, the image is present, although this is probably one of the worst polishings I have done in a very long time–please don’t pay too much attention to that, nor the copper exposed in the corners! However, I would like to ask you all to look at the attached image and opine whether I am over-bromating or over-developing? Or both? Neither? Although you can’t see it on the scan, the plate is a bit weak and difficult to see. Your opinion counts! Thanks, as always.

 

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[jgmotamedi]

I bought a complete one many years ago from Tim Merritte. I have mixed feelings about the head brace; my sitters hate it (although sewing a flannel cover for the little “fingers” has helped a bit), and it never seems to lock down as tight as I think it should. Still, it is clearly better than anything I could make on my own, and I am unlikely to spend the money to buy an antique, if I could even find one.

[jgmotamedi]

There was a nice hardcover boxed deluxe version of Daguerre’s manual (not that this one isn’t nice…) published by Winter House in 1971 with an introduction by our Beaumont.

[jgmotamedi]

At a workshop I taught we were using two big banks of photoflo lights three feet from the sitters, and were getting exposures around 3:00 at f2.8 with first cycle Becquerel plates. In my experience halogen lights are a waste of time and energy. They are just the wrong color light for Dags.

[jgmotamedi]

Updated response: some thoughts and questions about venting and safety

I ran a few searches on the forum about ventilation, and notice that a number of people are using non-vented (i.e.; filtered) fume hoods. While I think in many circumstances these are fine, I am concerned about their use with mercury. There was an article in the Daguerreian Annual sometime back about Sandy Barrie, an Australian Daguerreotypist who poisoned himself with mercury because he didn’t change his filter frequently enough. Clearly human error may have played a factor here, but I do note that few (none?) mercury filters come with an end-of-life indicator, so it is really impossible to judge—short of elapsed time—when they need to be changed. I suspect that these non-vented fume hoods would be fine with iodine and bromine, since the strong chemical smell will quickly give away when the filters have started to fail.

My own set up employs two different fume hoods. One, in my basement darkroom, is used for sensitizing and another, in the studio (a rebuild garage) is used for mercury development as well as working with or mixing any of the sensitizers. I divided my set up this way for a few reasons; first and foremost, I didn’t want mercury in my house, and I also didn’t want to mix mercury and the sensitizers (they like to eat metal and my mercury pot is all metal, and also theoretically the sensitizers can contaminate an exposed plate before development).

The mercury fume hood is a real 4’ lab-grade fume hood which I found on Craigslist. It was unused and free for the pickup, but required finding three friends to lift it and borrowing a truck. I had to build a table to place it on, and then vent it through the ceiling and roof. It requires a 10” vent, which was surprisingly difficult to find. Since I would be using mercury and occasionally sensitizers in the hood, it couldn’t really be any sort of metal other than perhaps stainless steel, which was too expensive to even consider. I ended up buying 10 feet of 10” heavy duty RFH (rubber flexible hose) which is intended to vent corrosive fumes. I vented the fumes through the roof, attaching the 10” tube to a 5’ piece of 10” PVC sewer pipe I found in a dumpster. If I could do it over again I would probably have used 10” PVC sewer pipe for the whole thing.

My second fume hood is used only for iodine and bromine, and is a pretty simple affair, a 34 x 18 x 18” wooden box with 10 x 26” door. I vent everything with a 6” aluminum hose out the top. I will eventually replace the hose with PVC. The hose runs out of the house and joins with a 450 CFM squirrel cage blower which is screwed in place under my rear porch. The blower exhausts into a big (40lbs) activated charcoal filter from an indoor garden supply. My thinking being that activated charcoal will absorb bromine and the iodine fumes, and what it doesn’t absorb can be safely vented outside of the house. Any thoughts on using activated charcoal for absorbing halogens? Obviously it will have to be changed every year or so.

I tested the fume hoods first using one of the cheap Dwyer vaneometers, insuring that they measured at least 100cfm at all points of the entrance. I then tested with a few smoke-bombs (I used smoke-bombs I bought at a fireworks store, but they can also be made out of saltpeter and sugar. The problem with the homemade ones is that they tend to spit more fire) to make sure there were no leaks. I think the smoke-bomb test is very important because it allows you to examine all parts of your exhaust chain before putting odorless mercury there. I once built a fume hood with a friend, and before we used it we tested it with a smoke-bomb only to find out that his blower leaked out the side and would have re-circulated some of the fumes back into his darkroom. The leak was fixed with a quick weld and by moving the blower outside and turning it into a ‘sucker”. I have since learned my lesson and try to place (if at all possible) the blower outside the workspace. It is quieter that way too. This wasn’t possible with my commercial fume hood, which has a built in motor.

[jgmotamedi]

I have been struggling with building fume hoods for a while, I recently bought a ‘real’ lab hood off craigslist, and can make a few quick suggestions. I will try to write something longer and post it in a day or so.

First, I would really go more than 465cfm. Maybe 700cfm? If you calculate how much you need, it usually is pretty low, in your case about 300cfm, but factor in that every foot of pipe and every 90 degree turn cut down the movement significantly. Also, I have found through lots of trial and even more error that the no-name fans (like you are probably thinking about buying from the garden stores) don’t live up to their rated cfm. I would recommend spending another $40 and buying a Dayton.

Second, consider putting the fan outside so it is pulling the air outside rather than pushing it. This will reduce the sound in your darkroom, but more importantly you wont have to worry about fan leakage, which seems to be a major problem with these little squirrel cages.

Lastly, TEST TEST TEST! Certainly buy a vaneometer (Dywer sells a functional cheap one), but also use smoke bombs. There is no predicting where leakage will be, and the easiest way of testing is using the colored smoke bombs. You can also make them yourself with saltpeter and sugar, but these tend to spit lots of flame, which might damage your nice acrylic hood.

[jgmotamedi]

I have three suggestions, but these are nuts-and-bolts issues rather than recommendations for ways of keeping people on topic.

First, an email function (or PM) on the forum to directly contact forum members.

Second, I notice that I am signed-off the forum after a undetermined amount of time. I much prefer to remained logged in, can this be changed?

Third, in addition to an the RSS feed, it it possible to have a subscription function which emails when a topic is updated?

I hope I am not going off topic here, as I am rather liberally interpreting the meaning of ‘suggestions for improving the CDags site’ for my own purposes.

jason

[jgmotamedi]

My first traditional daguerreotype in over two years!

It is underexposed and underdeveloped, but I am delighted that I have a recognizable image. More soon.

Details:

Quarter-Plate Daguerreotype

Iodine: yellow with red edges

Bromine: red with slight yellow interior

Exposure: 1:30 @ f5.6 with 8 55w Florescent bulbs

Development: 2:00 @ 176F

 

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[jgmotamedi]

Thank you, this is all very helpful. Anybody make their own KCn solution? Not that I want another horrid chemical in the studio…

[jgmotamedi]

Interesting, thank you Mike. If I understand correctly, the immersion technique depends on there be two different metals–copper and silver–on either side of the plate to create a mild current which deposits the silver on the silver, correct? I suppose one could easily enough sand the silver off the rough side of an electroplated plate and use your immersion method, or better yet, use a wax-resist during the original electroplating to ensure that there is silver on only one side.

jason

[jgmotamedi]

I am also interested in simple (thin) electroplating right before a final polish. I know a number of people on this forum do this. Are you making your own plating baths using KCn? If so, I would love to hear your recipes, as well as times, anodes, and amperages.

Has anyone used the so-called green plating baths? Do they work for Daguerreotypes?

[jgmotamedi]

Photolytic is absolutely correct that this is a very dangerous process and perhaps a very foolish endeavor, one which my few years of college chemistry do not prepare me. I have also been guilty of not sharing all of my information assuming, perhaps incorrectly, that no one was going to jump in the water with me quite yet. Ramping up chemical reactions, particularly exothermic ones like this, is unpredictable and can be incredibly dangerous. Mixing acids and oxidizers can lead to disaster.

That said, I assume the heat requirements for the Renaissance Man’s bromine synthesis is to the boiling point of bromine, or 58.8C/137.8F. Of course, this only reinforces Photolytic point, as I would be very reluctant to heat bromine, making it even more volatile and dangerous.

[jgmotamedi]

I am curious if people are able to successfully use those Aero-Ektars for Dags. I tried one several years back and found that the yellow/brown stain in the glass (allegedly from radioactive thorium glass) cut down the blue light so much that it became effectively an f5.6 or thereabouts, but with the depth of field of its actual aperture. I tried to “bleach” the stain with UV light, but never completely removed the color cast.

Anyhow, I have a few lenses I regularly use for Daguerreotypes and a pile of lenses I don’t use but can’t get myself to sell. For 4×5 or smaller nothing beats my 150mm f2.8 Schneider Xenotar. It wasn’t cheap, but it is so much sharper than anything else out there. Not much movement though. I also use a 11″ f3 Dallmeyer 3B Patent Petzval, wonderful image quality and surprisingly sharp on 1/2 plate, but too big to fit on my 5×7. Finally, I have a 240mm f3.5 Schneider Xenar which is also wonderful but heavy.

[jgmotamedi]

Ken,

Thanks for the link and research. This is very helpful and I will study it in more detail this week. Essentially, the process outlined by our Renaissance Man is very similar to that which I have been using. We both started with a bromine salt (I used NaBr he used KBr, the main difference is that NaBr is more soluble so I could use less water) and then used an acid (H2SO4) to make HBr, and then an oxidizer (MnO3 versus my use of KBr03) to pull the bromine from HBr. In fact, I suspect that nearly any strong oxidizer would work, such as potassium permanganate or any of the brominating tablets used for pools. The main difference is that our Renaissance Man is distilling the bromine, while I am not. His product was probably purer than mine, but I don’t know how much. My last attempt used 40g of NaBr, which gave me nearly 10ml of bromine, so the output is quite similar. I would like to see his tables and other data, this could be very helpful.

jason

[jgmotamedi]

The image of the Fisher bottle cap which photolytic posted also looks very similar to the Spectrum bottle I had a few years ago. I never thought to keep the bottle or look carefully at the cap. Mostly I kept the bottle as far away from me as possible.

Andy, if you do find any access to the all-PTFE caps please do let us know, I would certainly buy a handful. I ended up ordering a 30ml PFA vial and cap, which should be enough space for my purposes right now, as I have no particular need to store more than I can easily use. However I may order one of the smaller PTFE bottles and compare the results.

I will be running one more synthesis this weekend, and will attempt to careful document it with images so others can try.

[jgmotamedi]

Thanks Andy,

the chart and image are helpful. I have been looking into PTFE bottles, and see that there are different kinds of PTFE, of which ETFE appears to be less resistant to bromine than FEP or PFA. Here is an example of an all PFA bottle and here is a FEP bottle with ETFE cap. Lots of choices, but I am tempted to stick with glass.

[jgmotamedi]

Thanks.

I ran the synthesis again last night, and now have about 8ml of bromine. If I run it again with doubled amounts I should have enough to create my quick, as well as recharge it a few times. I will certainly write up the experiment, which is really quite easy. All it takes is a fumehood, a bit of glassware, and patience. Things any Daguerreotypist should have at hand.

A more relevant question right now is how do people store their bromine? Ken Nelson and I have been going back and forth about this. I previously had been storing my bromine in glass bottles with poly-seal (polypropylene) caps sealed with Teflon tape. Ken saved me by telling me that this is not safe, since the bromine can easily eat through the polypropylene. I switched to a glass bottle with a Teflon liner, although it still has a polypropylene foam underneath the liner. The caps are green melamine. I have never been completely happy with these bottles, as I know they don’t develop the tight seal I would like.

As I see it my choices are glass bottles with

phenolic, melamine or polypropylene caps

PTFE liner on polypropylene foam or PTFE liner on white rubber

There are also glass “reagent” bottles with PTFE stoppers. Any advice on bottles? I suppose I could order one of those PTFE bottles on Ebay but I am not sure about their quality.

[jgmotamedi]

Success!

 

I made about 2 milliliters of bromine this afternoon in a fairly simple syntheses.

 

5ml potassium bromide (KBr) were dissolved in 6ml of distilled water. To this I slowly–drop by drop–added 2.5ml of concentrated sulfuric acid (H2SO4). Things heated up a bit, although no other notable changes. I then slowly added–seemingly grain by grain–1.5g of potassium bromate (KBrO3). As soon as the first grain hit the whole solution started to turn orange. After about half was added dark blobs of bromine started to form on the bottom of the beaker. It was hard to get everything to dissolve, but eventually it did. I washed the bromine a few times with a bit of distilled water, and then poured a bit of H2SO4 on top, to dry the bromine. I have attached an image of the product with a bit of H2SO4 on top.

 

Over all it was pretty easy. I don’t think there is enough br for me to charge my box, so I will probably try this again, perhaps tomorrow, doubling the amounts. I will update with better instructions as I can.

 

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[jgmotamedi]

It is an interesting question, and one I have been thinking about. There are two catagories of bromine tablets, BCDMH and DBDMH. Apparently it is possible to extract the bromine from these compounds using KBr or NaBr and sulfuric acid. One possible complication is that BCDMH contains quite a bit of chlorine, and in the extraction process will also produce ClBr, which may be difficult to remove. On the other hand, as another halogen this may actually be an positive addition to the process, although one which may be hard to quantify and reproduce.

I am currently working on extracting Br using NaBr, KBrO3(Potassium Bromate), and sulfuric acid. If this works, I will also try using one of pool bromine tablets in place of the KBrO3.

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