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Fixer precipitates part 2

Getting back to the original query...

Whilst the subject line says "precipitates" could the same effect not be caused by particulates in the mixing / washing water?
 
Frank;

The sulfur and calcium hydroxide which may form are able to be called both because they precipitate, and they are particulate. I'm afraid that in this context it might be hard to differentiate. If there is dirt or dust in the chemicals, then you might have particulate matter.

I hate to get into another nomenclature contest, but IMHO, a precipitate is a particulate, but a particulate need not be a precipitate. A particulate that is a precipitate forms in the solution itself.

BTW, for Dan, I wonder if it is calceous hydroxide or calcic hydroxide? Natrious hydroxid or natric hydroxide? Oh well, you see the problems here too.

I would not worry about naming this a particulate unless some very dirty conditions prevail or the water is exceedingly dirty.

PE
 
PE - Yes, I knew the "all poodles are dogs" aspect. Rather than being concerned about the naming (which my post might have implied - sorry!) I was more concerned with resolving the issue.

Filtering the mixing and washing water (or replacing it with distilled) might be a good (inexpensive and simple) first step.
 
Frank, I agree. I suggested filtering the fixer. Even after the material formed, it can be removed by filtration thereby rendering the fixer useful.

I use tap water for all of my processing solutions. I do filter it first however to removed all particulate matter before it can get into my solutions. I use distilled water for all emulsion work though.

However, extremely hard water will go through a filter just fine and then end up forming a precipitate afterwards in some photographic solutions. Since the level of Calcium or other metal salts is usually low in terms of the chemistry involved, the removal of the solids that form is harmless to the activity of the photographic solution.

However, the precipitate from hard water can form 2 times. First it can form when you mix the stock solution, and then it can form when you dilute it to working strength. This is why most manufacturers add sequestrants to their formulas.

Alkaline solutions are more prone to forming these cloudy precipitates or particles, while acid solutions are less so. This, like all generalization can have a lot of exceptions.

PE
 
Well, I've learned something new today!

I'm in a hard water area (and don't I know it! ) but pre-filtering seems to have resolved the problems that I used to have. I'll bear post-filtering in mind, though - you never know what the future will bring!

Thanks PE!
 


What degree of filtering did you use? Coffe FIlter, or all out Brita type? I've been having the same thing happen to me lately with my TF-4 as well.
 
TF-4 states right on the bottle that you should mix it with distilled water. Given the cost of photo-chemicals and how cheap distilled water is compared to them, (I pay $0.99 per gallon at Rite-Aid), why wouldn't you just use distilled water to mix your chemistry?
 

I do mix all my chemicstry with distilled water, and since I still get these ugly dots, I'm try to address things that aren't so pure. Which is either a)The washing water or what hit me in the shower this morning

b) The clips I'm using to keep the sheets seperate in my drum for 4x5 processing. I never noticed the spot on 35mm or 120 film, but only on 4x5. So I looked at the clothpins I've been using to keep the sheets apart, and the metal spring isn't the same chrome color as when it goes in. I'm thinking the fixer is also reacting to this metal and that is the source of my precipitates. I'll run a batch of two sheets with no clip later with my standard procedure with fresh fixer later and see what happens. If they still show up I'll have to address the wash water.
 

Hi,
I wasn't referring to you in particular, but to everyone who mixes with tap water. If you think it's the wash water, you could try processing a 4x5 sheet in open trays so you have no clips, then just give the negative a quick rinse in distilled water before examining it for spots. If no spots, try washing the neg and see if spots show up.

Dan
 
I too am having some issues and have switched to bottled water for all of my film developing. I use the bottled water (.65 a gallon at the local market) for all the chemistry and then distilled water for the photo-flo.

The water in my area is hard water. My black kitchen sink has white residue on it.

Would a water filter take care of any of this?

What about a water softening system?
 
dslater said:
Hi,
... you could try processing a 4x5 sheet in open trays so
you have no clips, then just give the negative a quick rinse
in distilled water before examining it for spots. If no spots,
try washing the neg and see if spots show up. Dan
Click to expand...

Likely he has two or three tests to make.
First, tray process then wash as usual; the no clips test.
If that works it's the clips and he's done. If not:

Second, with clips follow the fix with an at least first distilled
water rinse. The more loaded the fix the more important a first
distilled rinse. Chances are remote but it is conceivable that
some insoluble combination is precipitating within the
emulsion.

The test combinations are for two variables, clips, and water.
Four combinations, one of which is already tested; clips and
tap water wash. So, no clips, tap and distilled and clips plus
distilled remain as tests. Sj, what fix? Dan
 

Well, he could do that - but my reasoning is this: if it's the clips causing the problem, then they likely cause the problem during processing when they're exposed to strong chemicals rather than during the wash. Therefore, tray process - verify no spots after fix, then wash. If you still have no spots, then it's the clips - if you do get spots, then it's the wash. - of course this is all moot as he seems to have determined that it's the clips.
Dan
 
I'm not sure what I'm seeing. Are these bits of white stuff on a negative or holes in a negative? I have used a lot of TF4 and never have seen the like. I have very hard water. I have to be careful not to stub my toe on it sometimes. I cannot use carbonate in my print developer without a lot of EDTA. Even if I had precipitate in the fixer, it probably would not settle on the film due to the vigorous agitation. IOW, I'm stumped.
 

Not if you are properly British. Some poodles are dogs, others are bitches. I had a British friend once....oh, forget it.
 

Just a thought, is it possible that dust is settling on and sticking to your wet film as it dries?
 
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