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Photo Engineer
10-23-2009, 12:35 PM
Ray;

Looking again, I see that the clothes pins were cropped out of the photo when I resized it.

I use the connnectors to join segments of tubing and nothing else. The tygon tubing used for peristaltic pumps is extremely expensive running in the range of $100 / small package of 25 ft or so. The other tubing may cost under $10 for the same length but will not work with peristaltic pumps.

As for the 90 degree connectors, just a whimsical way of turning a corner? After all, the setup is not completed yet. But, I found that the 90 degree connectors allow rapid positioning and movement between beakers on the input side, but on the output side the clothes pins allow accurate and rather permanent positioning to be made. So....

PE

hrst
10-23-2009, 01:36 PM
I've considered that we will use 50 mL syringes controlled with stepper or servo motors to avoid tubings and pumps. Syringes can be very near to the beaker where emulsion is made, with maybe about 10-20 cm tubes, thus minimizing the loss of solutions and making things easier. Syringes can be heated with a water bath. 50 mL syringes are quite cheap at VWR. But, maybe this is a little early for us now :D. Our next emulsion will be the same dump&stir type as this first -- it's really easy.

Photo Engineer
10-23-2009, 01:45 PM
Just FYI, VWR in the US will not sell to me or any individual. They will only sell to a corporate entity.

PE

hrst
10-23-2009, 02:07 PM
Yeah, I noticed this problem a while ago... So I established a small one-man company (or what it's called in English?) where you don't need any capital or much bureaucracy to run it. It cost 65 EUR to establish but now I can order anything from VWR or other companies that don't sell to individuals. I named my company: "A. Alhonen Motion Picture Laboratory"! No laboratory services available yet, though :D... VWR is fun, I ordered a 300 EUR order and now they deliver one or a few items every day using a large truck, even if it's some $3 small laboratory spatula... And then they don't sell to individuals. Insane. But, I got erythrosine, thymol, glyoxal and methanol already from them.

Photo Engineer
10-23-2009, 02:21 PM
It is getting harder and harder to buy chemicals in the US, and shipping is quite expensive. Many companies will not ship analog photo chemicals at all. You must pick them up at the store. This is particularly true of B&H in Manhattan. If this continues, then it will be totally impossible for our work to continue in the US, nor will most alternative photographic systems be possible to pursue due to their use of "dangerous chemicals".

I was told by one company that they could ship to me, but first I had to prove that I had a qualified storage facility for chemicals on the premises and a qualified person to maintain it. For photographically useful chemicals?

Also, for many chemicals, you must have a DEA form on file with the company that includes photo ID.

PE

Tom Kershaw
10-23-2009, 02:32 PM
It is getting harder and harder to buy chemicals in the US, and shipping is quite expensive. Many companies will not ship analog photo chemicals at all. You must pick them up at the store.

PE

Will they ship packaged products like Kodak Ektacolor RA developer and bleach fix?

Tom

hrst
10-23-2009, 02:34 PM
!

I thought this was difficult in Finland!

Just ten years ago, all pharmacies supplied most chemicals for anyone. Well, nothing that is directly used to make drugs, but all normal things. We have some small bottles at our darkroom that have a sticker from our local pharmacy; they are silver nitrate + acetic acid solution. Nowadays, you get very odd gaze if you ask for any chemicals at all.

This is insane, because the real criminals surely have their ways to get any chemicals they want.

dwross
10-23-2009, 02:58 PM
If this continues, then it will be totally impossible for our work to continue in the US, nor will most alternative photographic systems be possible to pursue due to their use of "dangerous chemicals".PE

Aw, Ron. Just when I thought you'd given up 'doom and gloom' as a hobby, you have to go all scary, and it's not even Halloween yet.

I have had no problem getting the chemicals I need. I do have an Oregon business license, just a simple sole proprietorship like many photographers. I have had to fill out a form once or twice, but as soon as companies find out what I'm trying to do they couldn't be more helpful. I get emails, and even once a phone call, from sales reps and company scientists - all interested and supportive. And, if now and again, a horribly dangerous chemical goes missing on us, there will always be workaround alternatives. Have faith. There is a fine line between 'realism' and toxic pessimism.

There is a great love of photography out there in the world, and an appreciation for alternative processes and the importance of preserving them seems to be growing by the day.

I love BH. They are my go-to guys for equipment, but why would you go to them for chemicals? Besides the Formulary, I have great luck with the Science Company, http://www.sciencecompany.com/ and the Lab Depot, http://www.labdepotinc.com/, plus misc others.

d

p.s Go Team Finland!!

hrst
10-23-2009, 03:12 PM
Yeah, you have to survive! Even if you have to mine the silver yourself and have your own cattle to get gelatin.... It's worth it when you can make your own film!

Anon Ymous
10-23-2009, 03:25 PM
...This is insane, because the real criminals surely have their ways to get any chemicals they want.

Having seen a National Geographic documentary about methamphetamine dealers/producers, I'd say you're 100% right.

Photo Engineer
10-23-2009, 04:04 PM
Well, it is nice to see people getting the chemicals they want.

VWR will not sell me a new reference electrode but some other companies will. I can get Silver Nitrate, but not Potassium Nitrate (because it is used to make bombs!), but you can get Nitrates most anywhere for fertilizer. Most hardware stores sell a dreadfully impure version of Potassium Nitrate for gardening use (it contains a lot of KCl). At the risk of being condemned, I'll tell you that some Silver salts are more explosive than you might imagine!

So, for those who say it is easy to get chemicals, I say go for it. But don't count on it being easy forever.

The Lab Depot is very good. It is a source I suggested in the workshop to my students, but I only get hardware from them. I also suggest Antec, www.kyantec.com for chemicals. I get my Erythrosine from them among other chemicals and hardware.

So, it is a mixed bag, but remember, I have watched this trend over time and seen the tightening of regulations. And, I might add a big YES to the quesiton "does this extend to prepackaged kits?". Some companies will not ship kits out. You can only pick them up at the store.

Look at UPS regulations. I cannot ship a developer. I don't have a license for shipping alkaline solutions. (Does that include Milk of Magnesia?). They have a large poster on the counter with 3 major prohibitions. Alkalis are one. Now, I can go across town and get a license from FedEx, and then take the open package to them for packing, pay an exorbitant fee, and have them ship it. UPS will reluctantly do the same from their main shipping depot here in the city.

PE

Emulsion
10-23-2009, 06:06 PM
HRST, Very impressed by your results! Fantastic work.
PE, Your Millipore setup has me intrigued. I understand that you use it to concentrate and wash the emulsion. Is this correct? From what I have read the primary reason for concentrating the emulsion is to use it in a curtain coater. Is this also correct? Hope you can briefly explain.

Yours Intrigued,
Emulsion

Photo Engineer
10-23-2009, 06:33 PM
Noodle washing of an emulsion causes it to absorb up to 10% or more water from the washing process itself, thereby diluting the emulsion. I have seen cases of 50% absorption which really dilutes your emulsion. This is true of some Ammonia emulsions that may be still a bit alkaline.

Therefore, UF (Ultrafiltration) is used on most all emulsions to remove unwanted salts at the end of the making process. This is regardless of final coating method.

Concentrated emulsions have been used in extrusion, slide and curtain coaters for years, as long as UF was available. It is just that it is more critical in slide or curtain coating but it is always nice to have an emulsion that is always 1 Kg per mole of silver. It makes calculations easier. :)

PE

hrst
10-23-2009, 07:40 PM
Noodle washing of an emulsion causes it to absorb up to 10% or more water from the washing process itself, thereby diluting the emulsion. I have seen cases of 50% absorption which really dilutes your emulsion. This is true of some Ammonia emulsions that may be still a bit alkaline.


This was probably our biggest mistake first. We didn't neutralize ammonia before noodle washing and washed in 16...17C tap water for two hours. It may be about 50% absorption :). This is probably why we had to adjust coating blade gap to 400 um instead of initial 200 um and our initial coatings looked good in red safelight before drying but didn't work at all.

Now we have a pH meter and we will refrigerate the wash water, and squeeze off excess water from noodles before re-melting. We also have a better noodelizer now, it makes thinner noodles, they should wash faster if I'm right.

Is there any reason why we cannot just lower the water volume in initial solution, say, 10%? It would then dilute to a proper value.

Photo Engineer
10-23-2009, 08:26 PM
I wash in 4 deg C distilled water, and check the wash water as I pour it off for halide salts with a Silver Nitrate solution. When no Silver halide ppt. forms, the wash is done. I try to stop before that point by judging the mild cloudiness that forms as being the best point to stop.

My Ammonia makes (SRAD) are adjusted to pH 6.0 before washing. I use dilute Sulfuric Acid, as it is best in reducing swell and has no bad effects.

The vAg measurements will help this process become more accurate.

PE

hrst
10-23-2009, 09:29 PM
Sulfuric acid contains sulfur but it has no effect. Okay. Then again, sodium thiosulfate contains sulfur and it is used as a source of sulfur for sulfur sensitization. Am I right that the difference lies in the fact that thiosulfate ion has two sulfur atoms whereas sulfate has only one?

Photo Engineer
10-23-2009, 10:05 PM
No, it lies in the fact that Hypo decomposes to Ag2S on the surface of Silver Halides, but H2SO4 does not.

PE

wildbillbugman
10-23-2009, 10:39 PM
:DI just received an order from VWR. Nothing dangerous unless your a 2-year old. But still,I bought as an individual with no business license of any kind.
Photo Engineer-Mabe they know who you are!:D
Bill

Photo Engineer
10-23-2009, 11:26 PM
Bill;

I ordered a reference electrode from them 2 weeks ago. They took my order information and told me that in 4 days or less they would inform me if they could accept me as a customer without a business account (which is a real mess in NYS).

As of this date, they have not replied nor accepted my order.

PE

totalamateur
10-24-2009, 05:57 PM
Why not take out a name in another state? In texas it's $10 and 1 form, unless you want a crop. or LLC. You don't have to do busines sin the state where you are liscensced.