Did some testing of liquid bromine on various kinds of plastics today. Only PTFE was non-reactive as far as I could tell. Have plastic samples now sitting in a container with iodine crystals.
Daguerreotype Diary, Daguerreotype Diary 2012 | andy | January 1, 2012
Courtesy Lib. of Congress
Today is (more or less) the day that in 1839 saw the public announcement of the daguerreotype process. Thank you Louis and Joseph!
Having some time off from work. Have created what (I hope!) are the final cutting templates for the stainless steel dag plate project. Also picked up an odd Packard type shutter on e-Bay that I may try to replicate in acrylic. Also spending some time on finalizing the sixth plate camera and experimenting with creating [...]
Two straight days of prepping plans for laser cutting. Steel plate cutting templates, lens mounts and film holder mounts for the B&J 8×10 and some experimental 35mm plate holders made out of 1/32 ABS. Not quite done, but should be good to go when Pagoda Arts reopens after vacation time. A great leap forward.
Did a dry run today of the new plate cutting templates at Tech Shop. Ran into some problems with the first cut and had to back off on the production run. Need to make some template adjustments. The good news is that the cutting is three times as precise as it needs to be. Finished [...]
Have been slowly moving forward with my experiment to create stainless steel based plates. Today I plan to finalize the cutting templates so I can cut up the 1′x2′ piece I had plated. The plan is to use 1/16″ acrylic laser-cut templates to guide the cutting on the 40″ hydraulic shear at TechShop. The real [...]
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PTFE=Teflon ?
Why not just use glass?
I’m looking at designing a fuming box as well and would be interested in the reason to not use glass.
Hi Ben. Good question. If you are interested in the shortest and most proven path to a fuming box, go with glass. It will get you making dags in short order, work well and last for years if you avoid exposed metal in your design. I am an experimentalist at heart and enjoy the process of trying out new things. I don’t have a way to form glass, so am stuck with existing shapes (pans/trays) that don’t necessarily work well with some of my design ideas. That leads me to look at alternate materials that I am able to fabricate with more easily. Here is a short video of one design I have been playing with. http://youtu.be/moUfrlAQGFw. And yes PTFE is the generic name for the brand Teflon. Good luck with your fabrication efforts, please consider sharing information and pictures on cdags.org when you are done.
Thanks Andy for the quick reply. I see where you’re coming from now. I saw your double slide fuming box when you first posted it. It’s a great idea. You used acrylic which is fairly easy to work with and join. But when using PTFE it probably gets a little toughter. PTFE is pretty expensive and usually comes in thin sheets. How do you plan on joining the seams?
Hi Ben – PTFE is a challenge to join. In the sliding box I just laminated a textured PTFE sheet to the acrylic for the box cover. This worked quite well although there has been some question about the longevity of the cyanoacrylate glue used. I have been thinking about lining the insides of the box as well. That gets a lot more exacting however and I don’t have a good plan for sealing the edges. It’s unclear that is required however. It is quite clear that acrylic will hold up for some time to both iodine and bromine. The question is for how long – and it is a difficult question to answer. It is also clear that the plastics are more permeable to the vapors than glass. But again it is difficult to find out how much. At present the sliding box is charged only with I2 – and it does leak some fumes, subjectively it doesn’t seem any more leaky than the glass based boxes I used to have. It’s not like you get a perfect seal with the ground glass edges. But it is pretty hard to quantify. Ergo my testing program…