[Andy Stockton]

A few more

 

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[Andy Stockton]

Hot off the presses.

 

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[Andy Stockton]

At the moment I can see the tour guide,

[Andy Stockton]

So the silver disk rests on the lip around the hole and the “backside” dark slide holds it in place? Or do you put some tape on the disk?

[Andy Stockton]

On a simpler note I am happy to report that a sample unit of the all PTFE bottle cap is winging it’s way to my house for testing from Plastomertech. I have sent for an appropriately sized PVC reinforced amber glass bottle from another company as well. When I have both in hand I will decant my Bromine to the new bottle and begin a testing cycle. I will let the membership know the results. Of course since a long time trial is the only definitive answer, I will be reporting periodically for a while.

Plastomertech requires a $150 minimum order, and in small quantity the 28-430 size cap is $11.37 USD each. Once I have completed some testing I would be happy to put together a group order for those who are interested. (I may add a small surcharge to help support the CDags hosting costs if people are supportive of that that).

[Andy Stockton]

Aero-Ektar radioactivity.

http://home.earthlink.net/~michaelbriggs/aeroektar/aeroektar.html

The camera looks great, I hope it performs well.

[Andy Stockton]

Ken – what a great find! I hope you will be sharing other portions of this legacy in the various areas of the forum.

[Andy Stockton]

Interesting resemblance between the Fisher bottle top and the Plastomertech product. Does the Fisher bottle top have a number imprinted on it? I have written to Plastomertech requesting information on a retail supplier.

 

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[Andy Stockton]

You inspired me.

http://www.plastomertech.com/bottlecaps.htm

Still haven’t found prices or a retail supplier, but I will look.

[Andy Stockton]

A while ago I bought some pure PTFE bottles from a place called Structure Probe, Inc.

 

Catalog # 0233-AB Pure Virgin PTFE Jar 15 ml $10.82 and

Catalog # 01963-AB PTFE Dropping Bottle for Laboratory Use 25 ml $36.63

I got them to test but have not done so because I have no need of the bromine yet. I don’t know if they will “weep” but they seem much thicker than the clear looking PFA and FEP bottles. Those would make me very nervous. People have been handling chemicals safely in glass for a very long time. Our use of bromine is such that it involves relatively infrequent handling, so I lean toward glass too.

 

The SPI URL is http://www.2spi.com

PTFE Labware is here: http://www.2spi.com/catalog/plasticware/PTFE-labware.html

 

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[Andy Stockton]

Thanks for the warning about Alfa Aesar. I have it stored in a locked container outside of any living space and the storage space is vented. I have been inspecting it monthly, but think I will step up my frequency. I will watch these storage discussions with more interest.

What are the characteristics of the bromine bottle from Fisher Scientific?

[Andy Stockton]

Here is a link to the best (most complete) plastic physical properties chart I have run across:

http://k-mac-plastics.net/chemical-large.htm

It may be of some use.

The bromine I ordered (which my supplier got from Spectrum Chemicals) came in a brown glass bottle that has a clear plastic overcoating to help protect it from breakage. I have never opened the bottle, but presume it has a plastic cap with a PTFE liner. The cap is sealed in place with blue heat shrink tape. This bottle was purchased in April 2009 and the seal is still intact. Maybe Spectrum Chemicals would tell you what they use.

I had recommended PTFE bottles in the past (based on reading, not experience) but at least two members using them have noted that the bottles are gradually turning pink – probably not a good sign.

[Andy Stockton]

Well at my stage of progress it is likely just another diversion from the real work I should be busy with.

I think people are interested in anything that might decrease exposure times. Your suggestion of a simple quartz lens that passes UV fans the flames. Am I wrong in thinking that a lens that allows UVA and UVB would decrease exposure times? Both are plentiful in good old sunlight.

Of course the cost of a sophisticated quartz lens douses those same flames to a large extent. Then again maybe we are on the wrong track altogether (ref Mike Robinson’s comment about poor skin tones).

[Andy Stockton]

Irv – What does the “missing left half” of the spectrum graph you posted look like? Does the silver iodide still have a lot of sensitivity in the UVB range (320 nm–280 nm)?

[Andy Stockton]

Excellent. Keep us posted on the performance of your “homemade” when you use it.

[Andy Stockton]

So many variables. Was your cooler pack just a blue-ice insulated cooler, or one of those 12 Volt thermoelectric plug in jobbies? I have been thinking of one of those with a big sack of silica gel in it as a portable plate carrier. You still have to deal with getting the plate back to ambient without condensation however.

That UV meter sounds expensive. What kind is it?

Heading for Boston tomorrow to drop off my daughter at Tufts. She and her mother are alternating between excitement and despair every hour or so. I don’t imagine I will be getting much done in the coming week as I am cast in the “steady as a rock role”. Oh fun.

[Andy Stockton]

From medical sources 340-400 nm is a portion of the UVA spectrum now known as UVA-1 which is used in a variety of phototherapy lamps. It is a less damaging portion of the spectrum for skin, but it can still cause sunburn. Phototherapy lamps are available in a wide variety of configurations and power levels, but unfortunately like all medical rated equipment they are quite expensive.

[Andy Stockton]

Is there already a source that defines in detail the spectral response of Becquerel and Mercury daguerreotypes? That would be useful in picking a supplemental light source. Also – for those of you using alternate light sources, are there any safety precautions that should be observed? Do you limit the time a person is exposed to your lights, or caution them not to look directly at the source?

[Andy Stockton]

Welcome Xose, we will look forward to seeing your work. Please feel free to join into the discussions in the forum area. Everyone is welcome whether seasoned pro or newcomer. There are also many useful sources of info in the Resources section.

[Andy Stockton]

Do you put your digital interpositive for the contact printing in direct contact with the iodized surface of the plate? I thought it was fragile?

[Andy Stockton]

Thanks so much to everyone for the wealth of information in your responses. I feel like I have had a personal consultation with most of the heavy hitters in the daguerreian world! I now have multiple approaches to experiment with and will begin to try them on my next “Dag Day”.

To Mike R. and/or Jonathan D. – I had already run across “Robinson Quickstuff” in relationship to bromine and plan to go that way when I finally ramp up for mercury. I had not heard that silica gel could be used as a modulator for iodine to even out the coating.

Would either of you advise me concerning the relative quantities? How much iodine mixed with how much silica gel?

[Andy Stockton]

Hi Jason-

Re making Iodine – this video displays the recipe I found that seems to use the fewest chemicals:

http://video.aol.com/video-detail/how-to-make-iodineelement/3683647584

but it creates a number of reaction by-products that may or may not be problematic. I am told the reaction equations are as follows:

“Re: Potassium Iodide + Conc Sulphuric Acid

NaI + H2SO4 –> HI + NaHSO4

8HI + H2SO4 –> 4I2 + H2S + 4H2O

6HI + H2SO4 –> 3I2 + S + 4H2O

2HI + H2SO4 –> I2 + SO2 + 2H2O

You get a bit of HI (steamy white fumes in moist air) but not a usable amount. You also get violet iodine vapour. You get some yellow solid due to sulphur forming. You get the smell of bad eggs from hydrogen sulphide. You also get a brown sludgy solution, due to the tri-iodide forming.” (From http://www.thestudentroom.co.uk/showthread.php?t=396437 )

There are recipes that require more ingredients, but may result in fewer unwanted by-products.

Here is a video of one such:

http://www.youtube.com/watch?v=CLhwkFKLdPA

and a link to the recipe http://www.homechemlab.com/iodine.html

I have no idea if the by-products in the first reaction can be removed by rinsing with water or what problems they would cause. Sulfur compounds contribute to the tarnishing of silver for instance, there may be other issues. One article I read suggested melting the iodine into a block to purify it.

As you can see this is a work in progress. It has been a very long time since I have been in a chem lab and I am not professionally trained in chemistry. As a result I proceed very slowly with these sorts of experiments, reading up until I am sure enough of my knowledge that I am willing to risk an actual experiment.

[Andy Stockton]

Hey Jason-

You may find iodine progressively more difficult to get in the USA. The DEA has made crystalline iodine a regulated list 1 chemical (pertinent info to be found at this link: http://www.deadiversion.usdoj.gov/fed_regs/rules/2007/fr0702.htm ).

Small retailers have virtually stopped carrying it because of the reporting requirements (the DEA must be sent information about the identity of every person buying the product). You can still find it on eBay, but those sellers are all in violation of the law at present if they are not collecting the required DEA info, and have registered with the DEA as a seller.

eBay sources also have the same problem they have always had – how good is the product?

So you may even find the eBay sellers choked off eventually, that is why I have put the time into investigating how to synthesize I2 from chemicals that (at this point anyway) are not controlled.

I personally think that the DEA’s approach to controlling methamphetamine production by controlling precursor chemicals is silly, but they didn’t ask me. I just hope somebody doesn’t let them know that drugs are made out of atoms, or they will pass regulations controlling those too.

But we must forge on somehow if we are to have our art.

[Andy Stockton]

Hi Jason – I encountered the same problems you found with the purchase of bromine – the chemical was fairly cheap, the shipping was the killer. I haven’t researched synthesizing bromine yet, but have spent a fair amount of time looking up synthesizing iodine crystals as I plan to try that at some point. One surprising source for that info was YouTube. I spent a moment searching bromine just now and came up with this http://www.youtube.com/watch?v=hbBVgufI9y4 – there are other videos on bromine listed, so you might want to have a look there.

I will be very interested in following your experiments. The main thing that has concerned me in “rolling my own” daguerreian chemicals (after safety) is whether I will be able to achieve adequate levels of purity in a home setting. Some of the iodine precipitation methods looked like you could end up with undesired halogens or acid contamination in your product. I found a process using KI that looks fairly straightforward and wont require methods that are precise beyond my “home lab” capabilities, but still wonder if the I2 I produce will have hidden flaws..

I know we have several members who are professionally trained in the sciences, so I hope they will chime in to help us stay safe and yet have good results. The difficulty of obtaining the required chemicals is yet another barrier to daguerreian practice that is likely to continue or even get worse in the future. Having information about alternatives will help everyone.

[Andy Stockton]

Hi Jason, welcome. It is good to know that you are going back into production. I have heard of and seen your work here and there, and doubtless those less beginner than I know it well. CDags, would be happy to set up a gallery for you if you have any scans of your previous work available. (And of course look forward to the next chapter). I will look forward also to the interchanges that your questions and answers will generate. As you say there is great benefit in a community, both for the sharing of knowledge, but also for mutual support of our art.

In any case dive in!

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