# An old femulsion formula I've found

Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by steven_e007, Jul 5, 2007.

1. ### steven_e007Member

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This formula is from a book called "Simple photographic experiments". I don't have the book, just the photocopy of the relevent pages, so I don't know who wrote it, but it refers to the 1906 issue of 'Practical Photographer', so I suppose it is well before WW1 and British.

I have translated the formula from imperial to metric and simplified the instruction slightly, but otherwise this is as published:

Solution A:

Potassium Bromide 5g
Potassium Iodide 0.25g
Gelatine 15g
Water 120ml

Solution B:

Silver Nitrate 7.5g
Distilled Water 45ml

Ammonia .880

Method:

Mix solution A using boiling water and stir until dissolved.

In a separate beaker dissolved the silver nitrate in the cold distilled water. Now add .880 ammonia drop by drop. It will turn muddy brown. Continue adding and shaking until the solution becomes clear again.

Place both beakers in a water bath until they both achieve 38 degrees C.

In red light:

Slowly pour B into A stirring vigorously with a glass rod.

Place the mixture in a water bath of nearly boiling water for 2 hours.

Pour into a clean cold porcelain dish and leave to cool to room temperature in the dark, at least 6 hours.

Now shred to noodles and soak in water for one hour, stirring occasionally. Carefully pour off the water and repeat.

Return to a beaker and place back into a water bath of nearly boiling water. When remelted, pour into a brown or opaque glass bottle and add 8ml of water containing 0.065g of Chrome alum*

After shaking, the emulsion is ready to coat the plates.

Final volume should be about 240 ml

*I think 1 gram of Chrome Alum in 100ml water would be about right, then add 6ml?

I'm curious as to what you all think before I try it. Obviously it will be unsensitized and very slow, but it doesn't have much silver nitrate in it, which appeals to me due to the cost! Compared with the other 'real formula' on the thread lower down this forum, it seems very high on gelatine and very low on silver. Is it still classed as a SRAD emulsion, with the ammonia added to the silver nitrate rather than the emulsion?
Is the ripening temperature a bit excessive? (It did specify nearly boiling). Will it work with an inactive gelatine?

So many questions, I suppose the best thing is to try it - but will I be wasting my time?

Cheers,

Steve

2. ### ben-sMember

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Interesting stuff.
I suspect that the addition of the Chrome Alum would render the emulsion uncoatable pretty quickly.
Maybe divide the batch in half and add the Chrome Alum immediately before coating?
I guess it's a small enough batch to make experimentally, without worrying too much about the cost.
Based on a quite I got a while back, I would estimate that this would cost around £10 - £15

No doubt PE can dive in and either confirm or debunk what I have said

3. ### steven_e007Member

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Well, being a complete novice, I'm not totally sure what the chrome alum would do to the gelatine...

I've got all the chemicals and equipment and I'm ready to give it a go, but I did think that a sensible first step, since gelatine is fairly cheap, might be to clean my glass and coat them just with gelatine. This gives me the chance to practice with melting, coating, drying etc. without wasting the all precious Silver Nitrate. I intend to have a play tommorrow.

Steve

4. ### ben-sMember

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AFAIK, Chrome alum is a hardener.
It will help stop the gelatin melting in the process chemistry.
EDIT:as confirmed here, Chrome alum is a hardener, and is the correct stuff to use if you're coating on glass /EDIT

In PE's youtube demo, he uses a dyed gelatin to test the coating properties.
You might try that - a few drops of food colouring in the plain gelatin would help you to see where it's going.
Let us know how you get on.

5. ### z-manMember

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hello jelo

why not spend \$.29 for a pack of sugar free(sugar in regular gelatine deserts is the largest by wieght and volume constituent) fruit gelatine desert and add the alum and try it-- the color is built in

disclaimer: DON'T STORE ANY LEFT OVER MIX IN REFRIGERATOR-IT IS A POISON AND THE ACCIDENTAL INGESTION -CAUSE IT LOOKS AND SMELLS LIKE JELO-COULD BE FATAL TO A CHILD OR SMALL ADULT-DISCARD LEFT OVER MIX IMMEDIATLY AND TAKE THE 29 CENT LOSS

i'm being introduced to the vagaries of gelatine on glass myself, and find that for the mechanics of the coating such an approach is very cost effective

VAYA CON DIOS

6. ### Photo EngineerSubscriber

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This emulsion is an SRAD (Single Run Ammonia Digest) emulsion similar to the one I posted earlier in this forum. It is a good formula which will work reasonably well.

It will be slightly slower due to the fact that the gelatin level is higher from what I see. As gelatin goes up, grain size goes down and therefore speed decreases.

The ammonia is 28%. DO NOT USE HOUSEHOLD AMMONIA. It is too dilute and will result in a poor emulsion. You must get the 28% from a chemical supply house. Also, be aware of the extreme fumes produced by this method. You will need good ventilation.

Try it, it will work.

Oh, chrome alum is indeed a hardener, and if you have not washed out all of the ammonia it will harden rather quickly.

PE

7. ### z-manMember

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gelatine issues

pe i dont mean to dvert this thread and appologise if i doso

i can get 250mg of 250 bloom 'photo gelatine "actvated"(?) for \$50

it is presalted afaik for a agno salt emulsion-included is a book of instructions and methods he uses-very comprehensive-the combination of the book and the gelatine may be worth the price?-i am moving towards the salt emulsion anyway-he gives emulsion speeds from 1/2-5 iso in different applications and coatings

he also adds iodides and bromides for more speed and other reasons

if i sh ould address this elswhere please tell me

vaya con dios

8. ### Photo EngineerSubscriber

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IDK what this is and I cannot comment on any of its characteristics or usefulness.

Good luck.

PE

9. ### steven_e007Member

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Thanks for the feedback, guys.

I will be making this emulsion this week. I've took the first few steps by aquiring all the chemicals and equipment I need. Tonight I will be preparing the glass slides (cleaning) and playing with some gelatine and alum.

z-man, thanks for the advice and warning about poisoning the family, but I have solved the problem of child interference completely - by not having any!

I have decided to use the garage (completely seperate from the house) as the emulsion manufacturing plant (!) as I can make as much smell as I like...

My main problem right now is the ammonia. I can not get .880 or anything anywhere near. Things have been getting very hard just lately due to the 'security situation'. I work from home and in my job use lens cleaning solutions containing alcohol and various solvents. My own company can not now send these legally to me, their own employee, by post. Most couriers seems to have imposed their own rules about not carrying liqued chemicals and refuse to carry anything.

We have a couple of excellent suppliers in the UK for photographic chemicals, Silverprint and Retrophotographic. Neither of them list any liqued chemicals anymore or many of the dangerous ones, presumably for the same reasons. Certainly no .880 ammonia.

We are currently in the middle of a big security alert in the UK after the plot by several doctors (DOCTORS?!!) to bomb airports - so this is not a good time to be approaching chemical suppliers for restricted chemicals

I have a plan, though...

After rummaging around in the loft I found two things that might save my bacon. Firstly a big box of chemical apparatus. Flasks, glass tubes, bungs, burrettes, etc and secondly a 100yr old book called 'A laboratory Outline of General Chemistry' by Hale and Smith, 1907. A beautiful manual written in a different era entirely, when people were credited with some common sense and before Terrorists and Health and Safety Officers spoiled everything.

This tells me how to make ammonia from Ammonium Chloride (which I can buy legally and get posted to me).

My other idea was to get a gallon of houshold ammonia (I can buy this in the shops, but it is only about 9% strength and I'm not sure what else it might contain) and put it in a flask, heat it and bubble the ammonia gas through some de-mineralised water.

Anyone know if this would work? And what strenth I could reach? And is their an easy way to test the strength? I have a brewing hydrometer, but would need to make rather a lot to be able to float this in it!

Anyway - this minor problem won't defeat me - it is actually starting to seem like fun

Steve

10. ### ben-sMember

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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.

11. ### z-manMember

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hazmat and 'security' issues

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

12. ### Photo EngineerSubscriber

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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

13. ### steven_e007Member

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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 :rolleyes: 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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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

15. ### rmazzulloMember

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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.

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16. ### Photo EngineerSubscriber

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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

17. ### steven_e007Member

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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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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

19. ### z-manMember

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JUDGES: PE: 9.9, 9.8, 9.9, 9.3. . .

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

20. ### Photo EngineerSubscriber

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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