Homemade emulsion help please

[Anthony O]

I've been really enjoying the DIY aspect of large format and the wet darkroom. With that in mind, attempting salt and/or albumen printing strikes me as the next logical step.

In mixing up the silver nitrate solution, there was a problem. Cutting to the end result, it turned into a pasty liquid, looking somewhat like thin Elmer's glue. I do not have tools to measure pH or specific gravity.

Here's what I did:
1) Dissolve 12 g silver nitrate into 50 ml of distilled water - no apparent trouble
2) Dissolve 6 g citric acid into 50 ml of distilled water - no apparent trouble
3) Pour the citric acid into the silver nitrate and swirl to mix - Immediate milky appearance and thickening!

It is my understanding that it should have stayed clear. All tools and containers were clean before starting, and only the correct chemicals were in the room at the time. (Nothing got inadvertently switched.) Everything was measured carefully. My scale has always been reliable.

I fully expect the suggestion that something wasn't as clean as I had thought. That's plausible and supported by the evidence but since I believed it was all clean and well-rinsed, I wouldn't know what to suspect as a contaminant.

So the questions are:
- Any ideas what might have gone wrong? If I try again, I'd prefer success.
- Might there be a way to rescue the solution? AgNO3 is expensive...
- Or maybe just ignore it and it'll be fine? I have doubts but if the experts agree...?

I have tried searching the forum but haven't found an answer yet. Thanks for all the answers on other topics that I have found!

- Anthony

[Tin Can]

Go look at https://www.timlaytonfineart.com/blog

There are others to find

[Anthony O]

That's gold, thank you!

I've only been in this side of things about a year but hadn't found this resource yet.

Much appreciated. :)

[Tin Can]

http://www.thelightfarm.com/Map/BitsAndPieces/22Dec2011/making_emulsions_1941.pdf

[Tin Can]

https://www.youtube.com/watch?v=jyiOe6vQyaM

[paulbarden]

I've been really enjoying the DIY aspect of large format and the wet darkroom. With that in mind, attempting salt and/or albumen printing strikes me as the next logical step.

In mixing up the silver nitrate solution, there was a problem. Cutting to the end result, it turned into a pasty liquid, looking somewhat like thin Elmer's glue. I do not have tools to measure pH or specific gravity.

Here's what I did:
1) Dissolve 12 g silver nitrate into 50 ml of distilled water - no apparent trouble
2) Dissolve 6 g citric acid into 50 ml of distilled water - no apparent trouble
3) Pour the citric acid into the silver nitrate and swirl to mix - Immediate milky appearance and thickening!

It is my understanding that it should have stayed clear. All tools and containers were clean before starting, and only the correct chemicals were in the room at the time. (Nothing got inadvertently switched.) Everything was measured carefully. My scale has always been reliable.

I fully expect the suggestion that something wasn't as clean as I had thought. That's plausible and supported by the evidence but since I believed it was all clean and well-rinsed, I wouldn't know what to suspect as a contaminant.

So the questions are:
- Any ideas what might have gone wrong? If I try again, I'd prefer success.
- Might there be a way to rescue the solution? AgNO3 is expensive...
- Or maybe just ignore it and it'll be fine? I have doubts but if the experts agree...?

I have tried searching the forum but haven't found an answer yet. Thanks for all the answers on other topics that I have found!

- Anthony

Hi Anthony.
That recipe for salted paper sensitizer is very similar to many variations of the recipe, so the proportions and method is correct. However, I do NOT use the Citric acid in making my AgNO3 sensitizer - you really don't need it unless you plan to keep the sensitized, dried paper for more than 24 hours before using.

So, that leads me to think there is a contamination problem. Are you 100% certain that what you have used is pure Citric acid, with no other additives?
Can your silver nitrate be saved? That's a good question. Without knowing why the solution went "pasty", the remedy is uncertain. At least it was only 12 grams of AgNO3 and not 120!

[Tin Can]

https://www.youtube.com/watch?v=tbh3qQUXdzU

[paulbarden]

http://www.thelightfarm.com/Map/BitsAndPieces/22Dec2011/making_emulsions_1941.pdf

Randy, this link, and the next one on YouTube are about making film type emulsions from scratch. Anthony is looking for a recipe for sensitizing Salt and/or Albumen paper. (Unless I have completely misinterpreted his post)

[Anthony O]

I had thought that the nitrate keeps better with the addition of citric acid. But if that's only after it's coated onto paper, I'd just as soon leave it out! I hadn't planned to keep coated papers much longer than it takes them to dry.

Said acid I purchased from Photographer's Formulary a couple months ago, this was the first time I had opened the can. The nitrate was also a recent purchase from Bostick & Sullivan, also previously unopened.

My strongest suspect is the bottle used for the final mix. It's a 4-oz (118 ml) brown glass bottle that formerly held vanilla. Washing was by vigorously shaking with dish soap inside, then rinsing. So if that was inadequate, the contaminant would be either some tiny bit of vanilla from the cap, or the soap but I thought I had rinsed really well afterwards. I obviously missed something, else it wouldn't have gone wonky.

Thanks!

[paulbarden]

I had thought that the nitrate keeps better with the addition of citric acid. But if that's only after it's coated onto paper, I'd just as soon leave it out! I hadn't planned to keep coated papers much longer than it takes them to dry.

Said acid I purchased from Photographer's Formulary a couple months ago, this was the first time I had opened the can. The nitrate was also a recent purchase from Bostick & Sullivan, also previously unopened.

My strongest suspect is the bottle used for the final mix. It's a 4-oz (118 ml) brown glass bottle that formerly held vanilla. Washing was by vigorously shaking with dish soap inside, then rinsing. So if that was inadequate, the contaminant would be either some tiny bit of vanilla from the cap, or the soap but I thought I had rinsed really well afterwards. I obviously missed something, else it wouldn't have gone wonky.

Thanks!

Hi Anthony.
The point of adding Citric acid to the AgNO3 solution is as a preservative once its been applied to the salted paper. There is no absolute requirement for adding the acid to the silver solution, especially if you plan to expose sensitized paper immediately after drying. (that's what I do.)
I would appear that you have the correct chemicals, having bought from two photography sources. However, one thing I have discovered is that sometimes Photographers Formulary chemistry has sat around a long time before being sold, and I've found that some materials go stale by the time I got them. But it sounds like you bought it from PF directly, so that seems unlikely.
How sure are you that your distilled water is really distilled water (no minerals)? Sometimes there are brands labeled as "distilled" water that are actually just deionized/demineralized if you look closely at the label. Minerals in the water can ruin a silver solution.
My only other suggestion would be contamination from the bottle you used. Reusing glassware that has previously been used for food substances is a gamble, no matter how well you rinse it out. Its better to buy new glassware specifically for each chemical and never use it for anything else, especially when making up solutions with Silver nitrate. Still, it seems odd that a tiny bit of vanilla contamination would result in the solution immediately turning to paste.

My suggestion is to start again, and omit the Citric acid.

[Tin Can]

No I did not 'miss'

I gave him and many others options for emulsion making

I don't specialize

I try to enjoy my time




Randy, this link, and the next one on YouTube are about making film type emulsions from scratch. Anthony is looking for a recipe for sensitizing Salt and/or Albumen paper. (Unless I have completely misinterpreted his post)

[jnantz]

Hi Anthony.
The point of adding Citric acid to the AgNO3 solution is as a preservative once its been applied to the salted paper. There is no absolute requirement for adding the acid to the silver solution, especially if you plan to expose sensitized paper immediately after drying. (that's what I do.)
I would appear that you have the correct chemicals, having bought from two photography sources. However, one thing I have discovered is that sometimes Photographers Formulary chemistry has sat around a long time before being sold, and I've found that some materials go stale by the time I got them. But it sounds like you bought it from PF directly, so that seems unlikely.
How sure are you that your distilled water is really distilled water (no minerals)? Sometimes there are brands labeled as "distilled" water that are actually just deionized/demineralized if you look closely at the label. Minerals in the water can ruin a silver solution.
My only other suggestion would be contamination from the bottle you used. Reusing glassware that has previously been used for food substances is a gamble, no matter how well you rinse it out. Its better to buy new glassware specifically for each chemical and never use it for anything else, especially when making up solutions with Silver nitrate. Still, it seems odd that a tiny bit of vanilla contamination would result in the solution immediately turning to paste.

My suggestion is to start again, and omit the Citric acid.

+1

[Jim Noel]

I second Paul's answer.
I have made salt print using Fox Talbot's original formulae, as well as similar papers, since the 1980's. I have never added acid to the silver nitrate or to the finished print. Mine are still in excellent condition.

[Tin Can]

Tim Layton

Heated emulsion rods

Youtube has it all

https://www.youtube.com/watch?v=tJ5rpGW_12Q&authuser=0

[Anthony O]

+1

Thank you all! Yes I'll re-mix the nitrate, and save the acid for stop bath when that's needed.

Paul, you asked about the water. I was careful to buy what's labelled as "distilled water," but didn't look closer. Re-inspection shows it's "Type III." Had to look that one up. It's the lowest grade, made by reverse osmosis. For cleaning glassware and other non-essential tasks it's fine. That said, it has worked very well for mixing up a wide variety of developers and other photo chemicals but I won't use it for this again. I'll procure a new, unused brown bottle and better water.

[Anthony O]

Wow, Tin Can, thank you for all the links! It's taking a while to get through them all.

[John Layton]

Ha! (equals "funny story")...back in 1987 I participated in a Platinum/Palladium/Albumen workshop with Rob Steinberg, at what was then called the Maine Photographic Workshops (now Maine Media Workshops) - and we were having a bit of a problem, in that nothing was working with our albumen trials...only very faint images were appearing.

With the group very frustrated indeed...it was on the third evening of that week, just after dinner, that several members, myself included, started to bombard one of the "failed" prints (which had been tacked to a wall outside the lab) with pieces of fruit from our "fruit cups" (that evening's dessert) and...lo and behold - bits of image began to appear where the fruit had landed!

Turns out that the citric acid content in the bits of fruit was the key to finally realizing "success," (also indicating that our batch of "laboratory grade" citric acid was defective)...and an overnight shipment of fresh citric acid saved the workshop!

Moral of the story? Always have some fruit around...because you never know when the fruits of your labors might depend on the labors of your fruit! :rolleyes:

[Paul Ron]

here is a link to a forum that has a dedicated section just for emulsion making. some of the participants were employed by film makers as well as wrote books on the subject, they can answer your questions directly. you can also find classes for emulsion making.

https://www.photrio.com/forum/forums/silver-gelatin-based-emulsion-making-coating.93/

enjoy!