Roger Hicks on Film Washing

[sevo]

Don't the chemicals in tap water vary significantly from place to place and time to time? At least, that's what my taste buds tell me.

Ready-mixed photo chemicals are generally equipped with stabilizers which will deal with just about anything legal in tap water. There are a few exceptions (Xtol storage life can suffer from the presence of iron ions in legal and not that uncommon concentration), and you might run into problems if you use a private well whose water is not fit for drinking.

But usually you'll run into far more issues (from frothing to emulsion liftoff) when using distilled water than when you use plain tap water from a public water supply. In doubt check the product sheet.

If you mix your own chemistry, you'll have to read and understand the recipe - many modern recipes contain protective substances, chelate builders and the like, just like the ready mixes from Kodak or Ilford, but there also are some that need distilled water.

Sevo

 

[RichL]

Would using bottled "spring water" take care of the problems that people have when using tap or distilled water?

 

[Roger Hicks]

The Ilford sequence and other water saving sequences work. However they require fixing precisely to the recommended time. Old practice often had it that only the development was done very accurately while fixer, stop and wash timing, temperature and concentrations were sloppily handled. In modern wash regimes you'll also have to stop and fix exactly to specifications, or the wash may fail to reach archival grade!

Not all that precisely. Yes, severe over-fixing (more than twice the recommended time) MAY adversely affect washing, but there's already a safety factor built into fix times, so very long fixing times are a bad idea anyway. Besides, doesn't everyone want to see the flm as soon as possible? That militates against over-fixing.

I was talking to someone from Ilford about this a few years ago and he said, "Fix for not less than twice the clearing time and not more than three times the clearing time, OR for the recommended time. When I pointed out that recommmended times were sometimes twice as long as three times the clearing time, he daid, "Not a problem."

As for short stop, my chums at Ilford tell me that any normal stop procedure (including no stop at all, straight to fix) will have no effect whatsoever on washing.

On the other hand, you are absolutely right that the Ilford sequence depends on non-hardening rapid fixer at an appropriate concentration and temperature (though the fixer temperature is nothing like as critocal as for the developer). Use traditional slow fixer (hypo) or a hardener or both, and all bets are off.

Cheers,

R.

 

[Roger Hicks]

Would using bottled "spring water" take care of the problems that people have when using tap or distilled water?

You shouldn't really have problems with most tap water, and bottled 'spring water' varies even more in make-up than tap water.

I use quotation marks because some 'spring water' is tap water, and vice versa.

Cheers,

R.

 

[RichL]

During the 20 years I worked in a lab plus my home darkroom for 50 I've never used anything but tap water. It was typically run through a particle filter but but that was the extent of it.

I actually asked because I hadn't seen it mentioned and thought their might be a reason why some people had to use bottled rather than tap water.

 

[Roger Hicks]

During the 20 years I worked in a lab plus my home darkroom for 50 I've never used anything but tap water. It was typically run through a particle filter but but that was the extent of it.

I actually asked because I hadn't seen it mentioned and thought their might be a reason why some people had to use bottled rather than tap water.

Of course, your evidence of 50 years is only anecdotal -- but it's the anecdote most people will tell (though it's only 40 years in my case), so it's evidence I'd give real weight to.

My suspicion is that those who worry are the victims of classic internet paranoia. "One person in 10,000 (or 100,000) has a problem? It's gonna be ME!"

On top of that, I betcha that a substantial minority of the people who think they have probems with the quality of the water out of their taps are doing something wrong somewhere else in the chain, which is causing a problem independently of the water.

It's a bit like dyslesxia. Dyslexia really exists, and can be a hell of a handicap (though a surprising number of the dyslexics I know are successful inventors or run successful businesses). But dyslexia is also a convenient way for pushy middle-class parents to pretend that their kids are something other than stupid or lazy, so it tends to be somewhat over-diagnosed. Likewise, 'bad water' is easier to blame than 'I don't really know what I'm doing'.

As discussed elsewhere in this thread, photographic chemistry and physics are staggeringly complicated. You need to understand a fair bit of physics and chemistry to begin with -- more than most people do -- and then you need to read a lot of very chewy texts and papers on the subject. Then, even if you do go through the physics and chemistry, it's deeply unlikely to improve your photography. This is why I tend to give up on the fine detail -- often, I can only just understand it if I think hard about it, and there are other things I prefer to think hard about. As Marty has pointed out, the only real reason to go much beyond the empirical is intellectual curiosity. But on the internet, as in real life, there are always people who think they know more than they do.

Cheers,

R.

 

[RichL]

Roger, just in passing. My home darkroom information is definitely anecdotal the lab (avg 15k orders a day) information however is from our chemist and he checked chemistry and water several times per shift. 🙂

 

[Roger Hicks]

Roger, just in passing. My home darkroom information is definitely anecdotal the lab (avg 15k orders a day) information however is from our chemist and he checked chemistry and water several times per shift. 🙂

Well, it's still an anecdote (in that it it refers only to one lab, not to a broad-based study) -- but it's a bloody convincing one!

And I'm sure someone will turn up on this thread with a real problem (usually well water), which some will read as "It can happen -- therefore it WILL happen to me."

Cheers,

R.

 

[Freakscene]

And I'm sure someone will turn up on this thread with a real problem (usually well water), which some will read as "It can happen -- therefore it WILL happen to me."

Anecdotal data:

It happened to me twice: once in Prague (old building, pipes with plenty of lead and other metals in them) and Adelaide (lots of iron, ditto on the old, although not as old as the place in Prague).

It really can happen.

Non-anecdotal data: only a few milligrams per litre of iron or non-calcium divalent cations in the water are needed to cause serious problems with the shelf stability of Xtol. I have data from controlled experiments that show this.

In general, I recommend deionised/distilled water only for Xtol and other ascorbate developers, and for the final rinse where marks are a problem.

In Christchurch, New Zealand, I didn't even need to filter the water. Magnificent, really. It tastes good too.

Marty

 

[Ronald M]

Been using TF4 fix for years now, no stop, and Ilford wash sequence with one extra wash at the end. Usual is a two roll tank with film on bottom reel, empty reel on top. 8 + oz of wash water

Negs are fine . Never had a roll go bad.

I also never reuse fix except for a test exposure I do not care if it is full of marks from precipitated silver from previous roll.

Use up the film fix at same dilution for test prints.

 

[maddoc]

The basic principles behind the chemistry of fixing are not really complicated but the interplay of gelatine / dye layer embedded silver containing micro-particles with hydrated ions from the liquid phase makes things complicated. Since the chemistry of tap-water can largely differ from place to place, photo-chemical products are usually designed (mixed) as best a best compromise to cover a wide range of tap-waters and thus using distilled water is usually not necessary.