Silver nitrate maintenance

[scratched&grainy]

Hi,
Does anyone have a tried and tested way of bringing silver nitrate back to life? The net is full of alchemists who stir this way, then that way, then expose to the midday sun during every other vernal equninox whilst chanting...etc.
Im looking for something more prosaic like add 10g of ammonium, or something.
My silver nitrate is pretty standard and has reduced by half in volume over time. It has started producing milky negs with virtually no contrast and doesn't register green.
My silver nitrate is :
ethanol 100ml, ether 100ml, collodion 125ml, cadmium bromide 1.5g, ammonium bromide 1.3g, cadmium iodide 3.4g, ammonium iodide 2.6g.ph about 4 or 5.
My developer is: distilled water 355ml, 95% grain alcohol 18ml, 10% vinegar 280ml, 2 tablespoons of white sugar and ferrous sulphate between 9g and 16 depending on how much contrast i want.
My fixer is sodium thiosulphate +tap water.
I have had good results with this in the past although maybe lacking a little detail in the blacks and whites but generally ok
Thanks,
Mark

 

[garysamson]

The above does not make sense. Your silver bath would be composed of silver nitrate and distilled water. over time, you should be replenishing this solution maintaining the bath at a specific gravity. I would suggest you get either the Scully / Osterman manual or John Coffer's manual on wet-plate photography to aid you in this matter.

 

[nawagi]

Simple Silver Bath Maintenance

1) Measure the specific gravity of your existing bath using a hydrometer. Measure the pH with a test strip.

2) Pour bath into a large glass jar (1 gallon sized pickle jar works well)

3) Cover jar opening with a paper towel and place in bright sunlight for several hours.

This is not "alchemy" - sunlight exposes the contaminants in the bath. The bath may turn cloudy and grey - that's what you want

4) Bring the bath inside and let it rest for a day to 3 - the contaminants will settle to the bottom of the jar.

5) Decant the clear bath off the dark layer of sediment on the jar's bottom. If you stir up the sediment, return to step 4 above.

6) Bring the volume of the bath back to what you want it to be with distilled water.

7) Add fresh AgNo3 to the bath in 10 gram portions, checking the SG after each addition. When the SG hits 1.070 - 1.080, you're done.

8) Add nitric acid to the bath ,if necessary, a drop at a time until your pH is 3.5 to 4.

9) Filter the whole shebang into your silver bath - maintenance complete.

10) Don't belittle this process ("vernal equinox" etc.)- its proven effective for over 150 years.

NWG

 

[scratched&grainy]

Ok, thanks.