Making liquid emulsion?

Hi gang!

I'd like to brew up some liquid emulsion, similar to what Rockland

makes, to print a photo onto glass. Besides silver nitrate and Knox

gelatin, does anyone have a recipe?

Thanks!

Dan

You will also need some halide salt such as Potassium Bromide. I made an

emulsion once about 10 years ago and while it is possible to do so, it is quite

messy and takes awhile to do properly. You have to "noodle" the emulsion

through cheesecloth several times.

Liquid light is a lot less hassle. The chemicals described below can be

hazardous if safety procedures are not observed so wear proper protection

when mixing and using them.

From Kodak pamphlt AJ-12 paraphrased in Arnold Gassan's Handbook for

Contemporary Photography 4th edition (pg.177) you will need the following:

Silver nitrate solution= 45 grams silver nitrate dissolved in 415ml distilled

water;

Gelatin/halide solution= 10 grams gelatin dissolved in distilled water to which

30 grams of potassium bromide and 1.3 grams of potassium iodide has been

added after the gelatinn swells.

"Raise the temperature to 53-55C and maintain it while adding the silver

nitrate (solution A) slowly (20ml every 10 seconds). Stir constantly, and

maintain the temperature for 10 minutes after mixing. Warm the gelatin to 43-

44C and mix the Silver Nitrate + Bromide + Iodide with the gelatin."

You then cool the emulsion and let it gel. Noodling is accomplished by

placing the gelled emulsion in a washed piece of cheesecloth immersed in a

bath of cold water. Twist the cheesecloth to force the gelatin through it and

form the noodles. "Strain this mass of noodles in a sack of 2 or 3 layers of

cheesecloth (no iron should contact the emulsion at any point in the process).

Wash the noodles by flooding them with cold water, allowing them to sit for 2-

3 minutes; drain, and repeat. Wash 5 times. Strain the remaining noodles

and heat them in a water bath to 53-55C; maintain that temperature for 15

minutes. Cool it to about 40C and coat it on the paper or other support you

plan to emulsify." Gassan goes on to say the emulsion is blue-sensitive only

with an approximate speed of ISO 10. It can be used both in camera and for

printing.

He also gives a formula for degreasing the glass and suggests giving the

degreased glass an undercoating of hardened gelatin (5 grams gelatin in1

liter distilled water to which .5 grams chrome alum has been added) in order

to help the emulsion adhere better. The degreaser (Kodak TC-1 tray cleaner)

consists of:

Potassium dichromate 90 grams

Sulphric acid, conc. 90 ml

water to make 1 liter

Dissolve the dichromate in water and add the acid slowly stirring constantly.

Note that dichromates are carcinogenic and sulphuric acid is corrosive. Silver

nitrate is also a chemical deserving respect as it may cause burns and

blindness, so use appropriate safety devices such as chemically- resistant

gloves and eye protection when handling this stuff. If you are not familiar with

the hazards you should check an online database for the MSDS. (Edwal

used to make a packaged tray cleaner which would probably work much like

the Kodak degreaser formula given above.)

Good luck.

The reason I don't want to buy Liquid Emulsion is cost: I'm building an electrolytic silver recovery unit for my lab (and I'll be getting spent fixer & blix from a small commercial lab), so rather than send the silver off to a refiner, I'd rather make my own silver nitrate, and play with it accordingly.

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I'll have to come up with some sort of mechanical filtering device for the extrusion process.

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Also, I have a question about the temps & mixing sequence: <br><br> <i>Silver nitrate solution= 45 grams silver nitrate dissolved in 415ml distilled water;

<br><br>

Gelatin/halide solution= 10 grams gelatin dissolved in distilled water to which 30 grams of potassium bromide and 1.3 grams of potassium iodide has been added after the gelatinn swells.

<br><br>

"Raise the temperature to 53-55C and maintain it while adding the silver nitrate (solution A) slowly (20ml every 10 seconds). Stir constantly, and maintain the temperature for 10 minutes after mixing. </i><b> Is this just the water and silver nitrate solution, or is this the gelatin/halide solution?? </b><i>Warm the gelatin to 43- 44C and mix the Silver Nitrate + Bromide + Iodide with the gelatin." </i>

<br><br>

Cheers!<br>

Dan Schwartz <br><br>

Those are Gassan's directions verbatim which I took to mean the temperature of the gelatin solution. It probably would not hurt to heat the silver nitrate solution to the same temperature though.

How do plan to make the silver nitrate? I've been cautioned in the past that the procedure of combining silver with nitric acid is quite dangerous.

Thanks for the warning on nitric acid. However, I've worked with hydrofluoric acid in a glass etching tank, and that is, by far, the nastiest acid of them all.

Cheers!

Dan

i can't remember where i came across this. i thought it was from the visual brothers

website, but i just went there to paste the link and couldn't find it ...

i have never done this, but it looks really easy ...

Clean the surface. Then apply the following binder:

to the whites of two eggs add

ammonium chloride    29 grains, dissolved in

wood alcohol        1 dram

water            1/2 ounce

Beat this mixture to a froth, then allow to settle. Filter and apply to surface. Allow to dry.

When dry, repeat the process.

Sensitize by weak artificial light, with

silver nitrate        40 grains

water            1 ounce

When dry, hold over bottle of ammonia to permit fumes to cover the surface. Print, as

usual, by sunlight. Fix in 10% hypo solution, wash.

i figured out where i found this and other recipes - it was the visual brothers :)

http://artnavigator.visualbrothers.com/printpictures.htm

good luck!

john

There is a mailing list for people that are interested in making their own emulsions:

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<a href='http://silvergrain.org/mailman/listinfo/silvergrain_silvergrain.org'>

http://silvergrain.org/mailman/listinfo/silvergrain_silvergrain.org</a>

Dan, you want to hold both halide solution and the silver solution at 55C before precipitating (mixing) and also want to hold the mixture at this temperature. Some old formulae for rapid plates call for ammonia solution in the silver solution, and that type of emulsions are made at a lower temperature (like 45C) and silver solution is kept at room temperature (25C) before precipitation. More modern practice is to avoid ammonia but use neutral process at a higher temperature, unless you need a super-large grains for some special applications like X-ray research.

The purity of chemicals required for emulsion making is MUCH more strict than regular darkroom processing solutions. Analytical reagent grade is the minimum grade you can use for good repeatable results. Some metal impurities at a couple of ppm level is known to affect emulsion. Silver recovered from fixing bath is probably contaminated with sulfides, lead, zinc, manganese, gold, rhodium, etc. because these are used in trace quantities in production of commercial emulsions. Sulfides may be present in a large proportion because thiosulfate in fixing bath decomposes and make silver sulfide.

Small scale emulsion making is a draining task, but it's a lot of fun to make even a very rudimentary emulsion in your hand. However, like no one wants to make their own wine because s/he thinks a better wine can be made at a lower cost, you don't do your emulsion making because you expect to pay less for superior product. It won't happen.