Stopbath - further to below

[dean_lastoria]

I just read people saying no stop bath. I was using Tri-X with Kodak indicator Stop bath. Got pinholes. Kodak said dilute it down. So I 1/2'd the dilution. Now I'm getting the pinholes again and on HP5 (FP5? 400any way). So I've now WAY diluted it. Since I'm just using coloured water now, if I just use a water bath, will I be breathing in some deadly chemicals when the negative hits the fixer? I do tray processing so I can't help but breathe the stuff.

 

<p>

 

Thanks

 

<p>

 

Dean

[terry_carraway]

No.

 

<p>

 

If you wanted to kill your fixer quickly, you could even go directly

from developer to fixer.

[ed b.]

Your pinholes are being caused by the sudden transition from the very

alkaline developer to the very acitic stop bath. If you will use a

water rinse immediately after the developer and before the stop bath,

you should be able to eliminate the pinholes. I have made this a

standard part of my developing procedure for many years now. It is

possible to eliminate the stop bath altogether, but it will reduce

the life of your fixer, so I don't recommend it.

[pete_andrews]

I always use a stop bath and I've <b>never</b> had pinholes in any

film. I don't use commercially bought stop bath though, just 10ml of

glacial acetic acid to a litre of water. Perhaps the problem only

occurs with higher developer temperatures; I've noticed quite a few

posts on this forum talking about developer temperatures of 75

Farenheit and above. 68 degrees has always been the standard as long

as I can remember, and I always develop at that temperature.

 

<p>

 

Potassium Metabisulphite at 10 grams to the litre would make a milder

stop bath. It's the chemical most commonly used to acidify fixing

baths, so it shouldn't give any problem.

[thomas_wollstein]

I have never used an acid stop for film, preferring an intermediate

wash. However, pinholes sound very much like the bath was improperly

used. They are presumably caused by the acid reacting with developer

alkali (such as soda), liberating gas (CO2). If this happens at a rate

too fast to allow diffusion of the gas out of the emulsion, small

bubbles may result, which then look like pinholes. Correctly mixed

stop is indeed not much more than coloured water, its concentration

typically being 5% or even less. Consider that you don't want to

positively acidify the film but to neutralise the alkali in the

emulsion. Not much acid is needed to accomplish this.

[pat_j._krentz_29_palms__ca]

If I may be so bold as to point out again, 1 oz. of white vinegar to

15 oz. water is a very mild stop, and I have used it at temps of 85+

degrees here in the desert. Regards, Pat

[john_hicks]

What developer are you using?

[dean_lastoria]

Ilfosol S. Wich is supposed to be idiot proof I heard -- But I'm

thinking of trying DDX

 

<p>

 

Thanks for the advise so far.

Dean

[nigel_smith]

Going off-topic but... <P>

My experience with Ilfosol S (over many years) is that I always

needed more development than recomended (for my enlarger setup), my

personal EI for FP4 was about 80 and once the bottle was open it

didn't last long! Once Ilfosol starts to change colour it's dead...

Caught me out once, thankfully on nothing important!<P>

I changed to Ilford Plus (LC29) and was much happier. I believe my

EI is up around the stated 125, I develop for less than the

recommended (pretty sure of this) and it keeps in an opened bottle

much better. <P> However, after reading many nice comments about DD-

X, I've bought some of that and are doing some tests. Too early to

form any conclusions though (and I've been reading the PMK threads

with interest!)

[j._patric_dahl_n]

How about using a teaspoon of citric acid in a litre water as stop

bath? Has anyone heard of the citric acid type of stop bath?

[pete_andrews]

I don't see any objection to Citric Acid. In fact almost any mild acid

could be used as long as it doesn't have a hardening or solvent effect

on the emulsion or throw a sediment. Citric, Boric, Tartaric, even

very dilute Hydrochloric should all be suitable. I bet even wine

maker's anti-oxidant tablets would work.

[thomas_wollstein]

AFAIK, Citric acid is the base for most of the odourless fixers. I

wouldn't recommend hydrochloric acid, as it's too strong. This means

that slight overdoses may be fatal. Besides, it's much more difficult

to handle and much more dangerous than citric acid. If I recall

this correctly from my chemistry lessons, there is even another

problem with strong acids: Strong acids tend to give a step-like

change in pH. The pH of the stop - and therefore that of the

treated film - is either very acid (if there was a little too much

acid) or very alkaline (if there was too little). (It's a bit like

with graphical films: They are either black or white, but never

gray.) Weak acids, otoh, have a smoother titration curve. This means

that a little too much alkali or a little too much acid doesn't make

so dramatic a difference in pH.

[pete_andrews]

OK, scratch the Hydrochloric if you're going to drink it as well. How

about Pepsi? That's got a fair amount of Phosphoric acid in it. ;^)

[terry_carraway]

Typically inorganic acids will be too strong in this use. These

include the hydrochloric, sulfuric, etc. Acetic acid and citric acid

are organic acids and tend to be "milder". They are also somewhat

self buffering (Thomas pointed out the results of this).

 

<p>

 

Citric acid is used by many since it has a much milder odor. YOu could

even use ascorbi acid (Vitamin C) but the cost is somewhat

prohibative.

[dean_lastoria]

Thanks for all your answers. You guys are way more helpful than some

(most...all) manufacturer's Q answerers. I'll keep my present roughly

1/150 of Kodak Stop bath and add the tray of water between the

Developer and Stop. If that doesn't work I'll try vinegar (Balsamic

and I don't need to tone!). And I went out and bought fresh Ilfosol.

Thanks

 

<p>

 

Dean

[terry_carraway]

Dean,

 

<p>

 

Don't use vinegar, it is the same as Kodak Stop Bath, but the

concentration is not controlled. So you will never know exactly what

mix to use.

[john_hicks]

Tray? You're developing sheet film? If so, I'll bet the spots that look like pinholes are actually caused by dust on the film when it's exposed.

 

<p>

 

Take a sheet straight out of the box, expose it to light and process it and see if you get the same thing. That'll give you the answer.

 

<p>

 

I really can't imagine ordinary stop after Ilfosol-S causing pinholes with HP5+.

[gene_crumpler18]

Eliminate the stop and use water before the fix. With film you can

track how your fixer is doing by keeping an eye on clearing times and

fix for twice the clearing time.