Why use vinegar? Why use stop? If one processes using
Originally Posted by fschifano
one shot chemistry as do some who rotary processes or
myself where single tray processing is employed, a stop
of any sorts makes no sense. Dan
While stop might not be necessary, I still use it. It is cheap and changes colors. Such a simple pleasure. Also, I can gauge the use of my first fixer bath by how yellow it is. I am always amazed at how much stop bath from paper processing transfers to the fixer even though I have a rinse step between stop and fixer. The color gives me some feedback about waht is going on. Similarly when the Permawash turns light purple from use.
Originally Posted by dancqu
Stop. Entirely superfluous when using one-shot fixer. For
Originally Posted by jeroldharter
that matter a second fix serves no purpose as there is
no build up of silver in the one very dilute fix. Dan
Well Dan, I was taught to use it in the late 40s and early 50s when I was learning. Then in the USAF and at Kodak later, they taught us "use a stop". I say "use what works", but I feel like Jerold might if someone who was a chemist started to tell him how to remove an appendix. It kinda trivializes all we have learned in our various fields.
I ask the question, why do you not wish to take the advice of the companies that create these products and the engineers who earned their living from it for years.
I posted the URL for the current Kodak recommendation and it included a stop.
This prompted me to do one of my famous - or infamous - analyses... From the B&H Web site: Kodak Indicating Stop Bath - Makes 8 gallons. $5.69 - or slightly more than $0.71 gallon. I *tried* to determine the price of Ozark 5% White Vinegar -- I am NOT sure, and I'll check the next time I'm grocery shopping with my wife - but I think it was $1.39 for 128 ounces; mixed 1:4, that would equal $0.23/ gallon of working solution - but before you break my fingers over math or the price of vinegar, I'll double check all this.
Originally Posted by fschifano
During the B&H search, I chanced upon Sprint "Block" Stop Bath - I Liter. Interesting - under "Features", last two lines:
"Block is an acid based solution, but the acids are buffered to minimize the side effects. Buffering protects print fibers for greater permanence, reduces emulsion swelling, staining, reticulation, and eliminates odors.
Block will also prevent carbonate gas ruptures of film (pinholes) when used as directed." (emphasis mine - ES)
I seem to remember a similar "cause of pinholes" from an Ilford site, a few years ago. I have been using a weaker dilution - 0.5% acetic acid - when I do use shortstiop in film development - and I haven't experienced pinholes for a couple of years now.
Ed Sukach, FFP.
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Yes; BOTH would be "Food Grade Vinegars".
Originally Posted by Photo Engineer
Expensive? Somewhere I chanced upon a century-old (100 years) Modena Balsamic Vinegar for $250 / 500ml. A "wine" vinegar, at that.
Being inherently **CHEAP** the chance of a mistake from me as far as this is concerned would be remote. I *do*wonder what it would taste like in a salald.
You cannot use the undistilled version, only the white (clear) distilled version. Please don't mistake these two versions.
Ed Sukach, FFP.
"Well Dan, I was taught to use it in the late 40s and early 50s
when I was learning. Then in the USAF and at Kodak later, they
taught us "use a stop"."
I used the usual stop for years. I though was not taught but
told or perhaps read the instructions. So what does Kodak have
for us to learn about rotary or single tray processing, one-shot
chemistry, water stop, lith printing, etc. We've gone beyond.
"I posted the URL for the current Kodak recommendation ..."
Likely very similar to the recommendation made perhaps
seventy years ago. Another one-size-fits-all instructions.
OC for AZO? Dan
My wife used to b**ch when I made vinegar from glacial acetic acid that I bought by the case from Kodak.
Why are there no speaker jacks on a stereo camera?
In the 19th century, there were three very good reasons to use a stop bath:
1: Developing by inspection in very strong developers, it really makes a difference whether the film gets 90 seconds or 95 of development.
2: Emulsions were soft, and hardener was necessary. So the fixer was sometimes at least as acidic as the stop bath.
3: An acid stop bath removes the "unsightly brown stain caused by certain popular developers" - like pyrogallol, pyrocatechin and hydroquinone...
-- Ole Tjugen, Luddite Elitist
They were right when they said stop helps extend the fixer. I've tried Vinegar but was not REALLY inpressed. The fixer is the most expensive chemical I use so what ever it takes to save money (money to buy more film) I'll do it. I still have 1.5 liters of stop so I'll be OK