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Go Back   APUG > APUG English Forums > Darkroom > Silver Gelatin Based Emulsion Making & Coating > An old femulsion formula I've found

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Old 07-09-2007, 08:11 AM   #11 (permalink)
 
Join Date: Jun 2007
Location: nyc
Posts: 142
Default hazmat and 'security' issues

Quote:
Originally Posted by ben-s View Post
Steve;
Have you tried a chemical supplier like Rose chemicals or Fisher scientific?
Fisher can supply both apparatus and chemistry, while Rose are a small company who just supply chemicals.

www.fisher.co.uk
www.rose-chemicals.co.uk
AFAIK, Fisher won't deal with individuals, but you should be able to purchase through a company.
I believe that rose will deal with individuals.

I wouldn't recommend making your own ammonia unless you have an accurate way of testing concentration.
ben-good links-fisher, here in the states, was allways a good source-i used to get from thm as an individuale but that was before 9/11

hazmat recs here nake it impoosible to order a small bottle of rodinal-$25 us fee for shipmnt by any carrier-you must but together an order large enuf since the $25 is per shpmnt

these false flag opperation non-issues of 'security' are allready putting a kink in business here that will cause them to be thrown out like the used toiletpaper they are

blair's position as bush's lap dog has put your country at grave risk from the destabilation methods used by the cia in many countries in the past

while watching sky tv coverage of the london bombing i was not surprised to see that rudolf guiliani was right there on the spot-the "hero of 9/11" who never even made sure that all the rescue workers were given info re the haznmat issues an/or any protective masks etc

people who risked their lives at the site are now dying and dissabled with no benefits or hospital coverage

can't you folks in th uk find hazmat qualified shippers and/or venders? or is it an issue of not being a registered company as opposed to an individual?

silverprint won't ship many items to the us because of these issues and it has made it very frustrating personaly

vaya con dios
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Old 07-09-2007, 11:29 AM   #12 (permalink)
 
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Default

Steve;

That 0.880 is the old Baume measurement of the concentration of a gas in water. It is about equivalent to 28% wt/wt of Ammonia gas in water. I have no idea how you would assure yourself of the right concentration but using household ammonia of 9% will require 3x more solution and end up making the emulsion more dilute. You might try that. By reducing the amount of water in some part of the formula by 2/3 the amount of ammonia (determined by trial and error) you might come up with a reasonable formulation.

I tried it with household ammonia just for kicks and it was much too dilute. I did not go on to remove water elsewhere from the formula, as I had 28% on hand and just went ahead with the real thing.

PE
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Old 07-10-2007, 04:26 AM   #13 (permalink)
 
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Default

Quote:
Originally Posted by Photo Engineer View Post
Steve;

That 0.880 is the old Baume measurement of the concentration of a gas in water. It is about equivalent to 28% wt/wt of Ammonia gas in water. I have no idea how you would assure yourself of the right concentration but using household ammonia of 9% will require 3x more solution and end up making the emulsion more dilute. You might try that. By reducing the amount of water in some part of the formula by 2/3 the amount of ammonia (determined by trial and error) you might come up with a reasonable formulation.

I tried it with household ammonia just for kicks and it was much too dilute. I did not go on to remove water elsewhere from the formula, as I had 28% on hand and just went ahead with the real thing.

PE
Hi PE,

thanks for the advice.

I've recieved replies now from emails I sent to both the UK suppliers I mentioned earlier and as I suspected the new regulations mean they can not legally ship .880 ammonia - and neither will anyone else be able to in the UK

I have ordered some Amminium Chloride to set up my own ammonia factory but as you say, no way to tell how strong it is.

Maybe titrating it against an acid until pH becomes neutral or something? It is a long time since I did any chemistry - I'll have to look that one up!

I'll have a good look at my emulsion formula to see if I can leave water out elsewhere and use your suggestion of using household ammonia.

Steve
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Old 07-10-2007, 10:41 AM   #14 (permalink)
 
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Steve;

You might try this.

Add ammonium sulfate to the emulsion after you make it, then add sodium hydroxide by the drop (about 10%) until you smell ammonia. You have made the ammonium hydroxide in-situ. Ripen the emulsion, and then add an equal molar amount of sulfuric acid (about 10% again). This will neutralize the alkali.

Then wash.

I'm working on a non-ammonia method, but the chemicals are very expensive and hard to control.

PE
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Old 07-10-2007, 12:39 PM   #15 (permalink)
 
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Default Good Grief...

PE,

That last bit of information was tantamount to putting a diamond in a beaker of clear water. If I didn't have prior knowledge, I would have missed it entirely.

Bob M.

Last edited by rmazzullo; 07-10-2007 at 12:50 PM. Reason: correcting statement
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Old 07-10-2007, 01:48 PM   #16 (permalink)
 
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Well, there is another way to Bob.

You could use Ammonium Bromide to make the emulsion. It will be different, but by trial and error you can refine it back to the right point. And, it would take less base and acid. Of course, sometimes, depending on emulsion, you don't even need to add the base and acid.

PE
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Old 07-10-2007, 05:23 PM   #17 (permalink)
 
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Thanks for the ideas, but yep, this is getting a bit deep for me!

Since this is my very first ever attempt at an emulsion, I want to keep it simple. I have cut and pasted those ideas into my blog of notes for future reference, though!

But, I have had my own 'eureka' moment.
After looking up specific gravity on wikipedia (no limits to the depth of my technical research!) I went to work and whilst driving along... bingo!

Specific gravity is the relative density of something at 20 degrees C compared to an equal volume of water at 3.98 degress C. Water at this temp weighs 1 gram per 1 millilitre, if I have understood this correctly. Therefore if I am making about 20ml of 0.880 ammonia (and .88 is the specific gravity, I think that is what the number means?) then 20ml, for example, should weigh 0.88 X 20 = 17.6 grammes.

I was lucky enough to pick up a really good laboratory chemical balance a few years ago, for mixing developers, that should weigh to with 0.1 gram and I've a good quality graduated cylinder which should get me to within 1ml - so If I fill a previously weighed bottle and stopper with a carefully meaasured volume of my freshly made ammonia and re-weigh it, I should be able to calculate the s.g. of this within a few percent. The more I make, the more the error goes down.

Does this make sense? Can anyone see a flaw in this method?

(And if not, can I name it after myself?!)



Right, I'm off to try burning some marble with a blowtorch (I need the quicklime to dry the ammonia

Steve
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Old 07-10-2007, 06:14 PM   #18 (permalink)
 
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I'm not sure degrees Baume are equal to specific gravity, but if so, you are correct. There is some disagreement on this in some of the texts that I have here.

PE
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Old 07-10-2007, 09:48 PM   #19 (permalink)
 
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Default JUDGES: PE: 9.9, 9.8, 9.9, 9.3. . .

Quote:
Originally Posted by Photo Engineer View Post
Steve;

You might try this.

Add ammonium sulfate to the emulsion after you make it, then add sodium hydroxide by the drop (about 10%) until you smell ammonia. You have made the ammonium hydroxide in-situ. Ripen the emulsion, and then add an equal molar amount of sulfuric acid (about 10% again). This will neutralize the alkali.

Then wash.

I'm working on a non-ammonia method, but the chemicals are very expensive and hard to control.

PE

PE- bingo

re hazmat shipping $, 'security', blah blah. . ., buying dry and constructing on site seems to be the way to go; i am structuring all my future buying of materials on this model

problem is , my ventelation system gets overtaxed, and my time for takeing/making images is eaten up while i hydrate and wait

for this reason i am going to get some dry stuf from saul bolanyos siince he has foreseen all of these issues and makes dry stuff that he says will pass all hazmat and 'security' issues re shipping plus he has done (unspecifyed)preparation and "activation"(unspecified)

i trust saul and his own work is world class, but he only makes his products when he gets an order, so as to avoid age-change and garantee 'freshness' ---so there are time issues along with the standard problems of gettin things from outside the country

amonia is a real problem-i spent a few yrs as a tool and die designer and the amonia fumes from the diazo processor started the process of over reaction to amonia fumes

my house keeper has same problem from her yrs of working in the commercial housekeeping industry--she has banned 'household amonia' from my house and i have to sneak it in

pe-you spent yrs around all kinds of toxics-you have no problems with the fumes etc???

"color key" materials were so pervasive in the printing and dirct marketing trade that i think i absorbed enuf amonia thru skin contact over the yrs to acct for some of neural damage i have-doctors just say "organic and nonorganic poisoning resulting from long time exposure"

thanx again for realtime right now use it info

vaya con dios
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Old 07-10-2007, 10:09 PM   #20 (permalink)
 
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There are substitutes for Ammonia, but they are hard to get and expensive. When I work things out I'll let the world know.

But, things move slowly. I'm on a tight budget being retired and only one person.

PE
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