VDB - Is this how the solution sould be when mixed fresh?

[ColinRH]

I have mixed 2 batches of VDB solution with 2 different sets of chemicals and end up with the same (what I think to be) unusable solutions.

A and B solutions mixed good and clear and mixed together as directed and remained clear. Part C (silver nitrate) added slowly whilst stirring. As it was added the clear green solution of A and B would temporarily go milky but would clear after a second or 2. As the very last 2-3 ml of the part C was added the solution seemed to go cloudy and then separate and go like curdled milk.
Is that right?
Nowhere in the instructions that I have read does it state or even suggest that would happen. It IS stated that the solution needs 24-48 hrs to ripen but not that it separates into a curdled section on the bottom and clear at the top. If it is left for 48 hrs - or even a week - it remains separated and thick on the bottom.

 

[Jim Noel]

You are getting a precipitate of some kind which can be caused by low temperature of solutions among other things.
I would coat, expose and process an image to see if the solution is still good. I sometimes get a small amount of precipitate which I filter out and it causes me no problem. AFter settling for 24-48 hours some of it may go back into solution.

 

[cliveh]

I have mixed 2 batches of VDB solution with 2 different sets of chemicals and end up with the same (what I think to be) unusable solutions.

A and B solutions mixed good and clear and mixed together as directed and remained clear. Part C (silver nitrate) added slowly whilst stirring. As it was added the clear green solution of A and B would temporarily go milky but would clear after a second or 2. As the very last 2-3 ml of the part C was added the solution seemed to go cloudy and then separate and go like curdled milk.
Is that right?
Nowhere in the instructions that I have read does it state or even suggest that would happen. It IS stated that the solution needs 24-48 hrs to ripen but not that it separates into a curdled section on the bottom and clear at the top. If it is left for 48 hrs - or even a week - it remains separated and thick on the bottom.

If you provide more details about your A, B and part C in terms of constituents, amount and water (type) ratio. We may be able to help.

 

[ColinRH]

Jim - thanks for the suggestion, that could be the answer, I'll try later. Would it help warming the bottle slightly to assist with mixing?

Cliveh - I have been using what appears to be the standard recipe used by Wynn White, Sandy King and Ed Buffaloe
A) Ferric Ammonium Citrate 9gm
Distilled water 33ml
B) Tartaric Acid 1.5gm
Distilled water 33ml
C) Silver Nitrate 3.8gm
Distilled water 33ml

The distilled water is steam distilled and rated at 1ppm impurity.

 

[cliveh]

Jim - thanks for the suggestion, that could be the answer, I'll try later. Would it help warming the bottle slightly to assist with mixing?

Cliveh - I have been using what appears to be the standard recipe used by Wynn White, Sandy King and Ed Buffaloe
A) Ferric Ammonium Citrate 9gm
Distilled water 33ml
B) Tartaric Acid 1.5gm
Distilled water 33ml
C) Silver Nitrate 3.8gm
Distilled water 33ml

The distilled water is steam distilled and rated at 1ppm impurity.

Colin, sorry I'm late in getting back to you, as I needed to look at my own notes which were in a different building. The only thing I can suggest is mix solution C into the combined A and B even slower. Try just two or three drops at a time stirring continuously, then add two or three more and so on.

 

[Tom Taylor]

I have mixed 2 batches of VDB solution with 2 different sets of chemicals and end up with the same (what I think to be) unusable solutions.

A and B solutions mixed good and clear and mixed together as directed and remained clear. Part C (silver nitrate) added slowly whilst stirring. As it was added the clear green solution of A and B would temporarily go milky but would clear after a second or 2. As the very last 2-3 ml of the part C was added the solution seemed to go cloudy and then separate and go like curdled milk.
Is that right?
Nowhere in the instructions that I have read does it state or even suggest that would happen. It IS stated that the solution needs 24-48 hrs to ripen but not that it separates into a curdled section on the bottom and clear at the top. If it is left for 48 hrs - or even a week - it remains separated and thick on the bottom.

I prepare my working solution 105mm at a time (the brown bottle holds 120mm). With the last batch I noticed that some of the ferric had precipitated out and was floating on top so I zaped it in the microwave for a few seconds - probably raising the temperature of the solution to ~80F - and it went back into solution. I leave it ripen for 3 days (72 hours) before first use. Sitting undisturbed there is a precipitate at the bottom and it is clear from there to the top. I always shake the bottle well to mix the contents and immediately pour out 1 tsp into a shot glass and add 6 drops of 5% Tween-20 and stir that in with a clean dropper and transfer to a small dish from which I coat the paper with a hake brush. I've noticed that some green ferric will settle to the bottom of the dish while coating but brush it on. I use one teaspoon of sensitizer for each 8x10 print. Here is an example of a print made a couple of weeks ago:

http://www.spiritsofsilver.com/yahoo_site_admin/assets/images/Bodie_Methodists_VDB_Untoned.331135834_large.jpg

Thomas

 

[ColinRH]

I've now made 4 failed solutions all ending up as described in the first post.
I then got to thinking of Jim Noel's suggestion and trying some to see how it works. In doing so I was thinking through the procedure and thought that when I make salt prints - which up to now is all I have done - occasionally the solution fails to cover the paper properly and I don't know that until it has been exposed. That of course is because the silver solution is clear liquid and in subdued light cannot be seen. I thought, well with VDB being green I'll have a better idea of the solution having properly covered the paper. It then hit me like a wet fish - you IDIOT.
Because all I have been making are salt prints it never occurred to me that the VDB solution is sensitive as soon as it is mixed! I guess you are ahead of me at this stage! I had been making it with a 75w lamp alight just 2' above my head!!
So stupid - anyway, thanks for all your interest and suggestions. I have made a print today and all seems well.
Thanks again.

 

[cliveh]

I've now made 4 failed solutions all ending up as described in the first post.
I then got to thinking of Jim Noel's suggestion and trying some to see how it works. In doing so I was thinking through the procedure and thought that when I make salt prints - which up to now is all I have done - occasionally the solution fails to cover the paper properly and I don't know that until it has been exposed. That of course is because the silver solution is clear liquid and in subdued light cannot be seen. I thought, well with VDB being green I'll have a better idea of the solution having properly covered the paper. It then hit me like a wet fish - you IDIOT.
Because all I have been making are salt prints it never occurred to me that the VDB solution is sensitive as soon as it is mixed! I guess you are ahead of me at this stage! I had been making it with a 75w lamp alight just 2' above my head!!
So stupid - anyway, thanks for all your interest and suggestions. I have made a print today and all seems well.
Thanks again.

I mix the silver nitrate solution under a red safe-light, but as VDB is primarily UV sensitive your lamp may not be the problem.