ilfostop storage question...

MrFus · May 20, 2022

I'm graduating from cinestill D96 monobath to Ilford chemistry to start working my development processing and while reading the data sheet on the Ilfostop I found that it mentions 7 day working strength...

I only shoot one roll of 120 per week, and usually develop it on my day off, so if I understand right once the mix is done I have 7 days to fully use that batch?

Can it be properly stored and used longer as long as the pH dye shows that the solution is not exhausted either by use on film or natural degradation?

Thanks!

darkroommike · May 20, 2022

Ilfostop is a citric acid stop bath, you might get growth of mold and bacteria in a reused, low concentration citric acid solution. You could make a much cheaper "one shot" stop bath using either citric acid of acetic acid. Or do, as many others do, and just use a couple of water rinses between developer and fixer when processing film.

pentaxuser · May 20, 2022

MrFus, I must admit that I have never noticed Ilford saying 7 days working strength until you pointed this out As was pointed out by darkroommike this short period has to be connected to its propensity for mold growth although 7 days does seem to be a very conservative estimate

However this and the low dilution rate makes it expensive in comparison to acetic acid stop

Unless you cannot stand the smell of strong acetic acid concentrate I'd choose one of those such as the Kodak stop. Alternatively low strength acetic acid of about 5% as found in pure white vinegar is relatively cheap and has much less of a pungent smell and just needs diluting to 2%

pentaxuser

Andrew O'Neill · May 20, 2022

W have been using Ilfostop at the school I teach photography at forever. Mixed up and used until it turns blue. It will depends on how much film it paper you or through it. I change the darkroom stock every week. That's after 30 students have had their way with it, running 5x7's through it.

MrFus · May 20, 2022

pentaxuser said:
MrFus, I must admit that I have never noticed Ilford saying 7 days working strength until you pointed this out As was pointed out by darkroommike this short period has to be connected to its propensity for mold growth although 7 days does seem to be a very conservative estimate

However this and the low dilution rate makes it expensive in comparison to acetic acid stop

Unless you cannot stand the smell of strong acetic acid concentrate I'd choose one of those such as the Kodak stop. Alternatively low strength acetic acid of about 5% as found in pure white vinegar is relatively cheap and has much less of a pungent smell and just needs diluting to 2%

pentaxuser

Thank you for the tip, I think that going for Kodak Stop as soon as I'm out of Ilfostop as is the option that makes more sense.

AgX · May 20, 2022

As long as you do not need a ph-indicator, which at single use makes no sense anyway, the way to go is the use of acetic acid (smell) or citric acid (odourless).

Over here one can get 25% acetic acid at the grocery and citric acid at the drugstore.

MattKing · May 20, 2022

I use Ilfostop citric acid stop bath for printing, because it smells so much better than acetic acid stop bath. In the printing darkroom, you spend a lot of time with your head over the tray, so the smell matters a lot more
I use Kodak acetic acid stop bath for film, and keep and re-use it if I'm going to be developing a batch of film in the next short while. If not, I use it at half strength, one-shot.
Until recently, the Kodak product was much less expensive per litre working strength than the Ilford product.
The indicator is more important to me for prints than film.
I have powdered citric acid available, and bulk white vinegar seems to be holding its low cost better than photo chemicals, so all this may change.
I recommend stop bath for film. If you are going to try using a water stop, it really, really, really should be running water.

Andrew O'Neill · May 20, 2022

MattKing said:
I use Ilfostop citric acid stop bath for printing, because it smells so much better than acetic acid stop bath. In the printing darkroom, you spend a lot of time with your head over the tray, so the smell matters a lot more
I use Kodak acetic acid stop bath for film, and keep and re-use it if I'm going to be developing a batch of film in the next short while. If not, I use it at half strength, one-shot.
Until recently, the Kodak product was much less expensive per litre working strength than the Ilford product.
The indicator is more important to me for prints than film.
I have powdered citric acid available, and bulk white vinegar seems to be holding its low cost better than photo chemicals, so all this may change.
I recommend stop bath for film. If you are going to try using a water stop, it really, really, really should be running water.

At home I prefer to use citric acid (I've got bags of the stuff from the DIY wine shop), or vinegar. Once we run out of Ilfostop, my students will be using vinegar. Got to save money for film!

Doremus Scudder · May 20, 2022

Well, you could just use Kodak Indicator Stop Bath. It is acetic-acid based and lasts indefinitely in working solution. Mold growth is not a problem. A bottle of KISB should last you years at your film-developing rate.

A liter of working solution should last some months and will likely start to turn blue before it ever goes bad.

On caveat: don't wait till the indicator in the stop has turned from orange/yellow to blue to discard the stop. At the first sign of discoloration (usually a grayish look to the yellow) the stop is no longer doing its job effectively. Toss it then and mix new.

Doremus

250swb · May 20, 2022

Doremus Scudder said:
Well, you could just use Kodak Indicator Stop Bath.

Ilfostop is and indicating stop bath.

250swb · May 20, 2022

MrFus said:
I'm graduating from cinestill D96 monobath to Ilford chemistry to start working my development processing and while reading the data sheet on the Ilfostop I found that it mentions 7 day working strength...

I only shoot one roll of 120 per week, and usually develop it on my day off, so if I understand right once the mix is done I have 7 days to fully use that batch?

Can it be properly stored and used longer as long as the pH dye shows that the solution is not exhausted either by use on film or natural degradation?

Thanks!

For film processing it is ambiguous in the description from Ilford, but if you keep it in a well stoppered bottle and keep the bottle nearly full use it until it starts to discolour. I mix five litres ever six months, and only then as basic housekeeping in the darkroom, and it's still always fresh at the end of six months (I suppose I really shouldn't flush it having said that. lol). I think perhaps the 7 day warning comes if you leave it out in a tray when printing, and also in printing there is a lot more carry over from the developer.

Doremus Scudder · May 20, 2022

250swb said:
Ilfostop is and indicating stop bath.

But it's citric acid base and the working solution has a short shelf life. The Kodak Indicator Stop Bath is acetic-acid based and doesn't have the limited lifespan.

Doremus

grat · May 23, 2022

My experience is that working strength Ifostop stores much longer then Ilford suggests.

I store it in (mostly) full brown glass bottles, and have re-used a month old bottle. I do mix it from heavily filtered water. Basically, as long as it hasn't changed color or turned fuzzy, it seems to work just fine as a stop bath.

I admit, I haven't checked the pH, so it's possible it's reached the point of being "just water".

Then again, my record is over a year for Ilfosol 3 concentrate stored in a 100ml bottle-- and that's supposed to die with a month or so.

snusmumriken · May 23, 2022

MattKing said:
If you are going to try using a water stop, it really, really, really should be running water.

Well, there are hazards to that, if your water supply is very cold compared with the developer, as it often is here in the UK. The temperature shock can cause the film emulsion to craze ('reticulation'), giving the appearance of monster grain with a regular pattern. I had that a few times in my early years. For this reason I prepare a small bucket of water at working temperature, and do a very rapid fill-and-dump 3 times, in place of an acid stop bath. I'm using Paterson System 4 tanks, so filling end emptying are very fast indeed.

The reticulation hazard also arises with the final rinse. So after dumping the fixer I pour water at working temperature into the tank, then gradually replace it by feeding cold tap water in at the bottom of the tank via a hose.

I use an acetic acid indicator stop for prints, and keep the diluted chemical in a bottle from session to session (sometimes months apart) until the indicator turns. Never saw a need to switch to citric acid.

pentaxuser · May 23, 2022

250swb said:
For film processing it is ambiguous in the description from Ilford, but if you keep it in a well stoppered bottle and keep the bottle nearly full use it until it starts to discolour. I mix five litres ever six months, and only then as basic housekeeping in the darkroom, and it's still always fresh at the end of six months (I suppose I really shouldn't flush it having said that. lol). I think perhaps the 7 day warning comes if you leave it out in a tray when printing, and also in printing there is a lot more carry over from the developer.

You may well be right about the 7 days applying to open trays. In which case it is a pity for Ilford's sake in terms of its sales of Ilfostop that it hasn't said so. Certainly in a Nova slot processor with cling film covering the slot I got a lot more than 7 days from Ilfostop and my concentrate lasted several years when I was using Ilfostop.

So, yes, it isn't as bad as all that but there are cheaper ways of buying acid stop.

pentaxuser

NB23 · May 23, 2022

All things being equal, ilford Stop is 8 times more expensive than Kodak stop. It’s basically like paying 80$ for 500ml of stop concentrate. That makes it their most expensive chemical by far, actually, and which is total nonsense.

I will never use Ilford stop bath again, and this is why I have 10 bottles of the Kodak stuff.

RalphLambrecht · May 23, 2022

pentaxuser said:
MrFus, I must admit that I have never noticed Ilford saying 7 days working strength until you pointed this out As was pointed out by darkroommike this short period has to be connected to its propensity for mold growth although 7 days does seem to be a very conservative estimate

However this and the low dilution rate makes it expensive in comparison to acetic acid stop

Unless you cannot stand the smell of strong acetic acid concentrate I'd choose one of those such as the Kodak stop. Alternatively low strength acetic acid of about 5% as found in pure white vinegar is relatively cheap and has much less of a pungent smell and just needs diluting to 2%

pentaxuser

+1

MrFus · May 23, 2022

NB23 said:
All things being equal, ilford Stop is 8 times more expensive than Kodak stop. It’s basically like paying 80$ for 500ml of stop concentrate. That makes it their most expensive chemical by far, actually, and which is total nonsense.

I will never use Ilford stop bath again, and this is why I have 10 bottles of the Kodak stuff.

It's crazy, you can make 8 gallons (30 liters) of Kodak Stop for $6.49... Paterson tanks use 500ml for roll of 120, I only shoot one roll each week! It is going to last me foreveeeeerrrrr!! Hahahahaha....

Now I only need to find someone who sell it locally or some retailer that can ship it to Florida!

NB23 · May 23, 2022

MrFus said:
It's crazy, you can make 8 gallons (30 liters) of Kodak Stop for $6.49... Paterson tanks use 500ml for roll of 120, I only shoot one roll each week! It is going to last me foreveeeeerrrrr!! Hahahahaha....

Now I only need to find someone who sell it locally or some retailer that can ship it to Florida!

Indeed.
Kodak mixes 16ml/Liter while Ilford is 50ml/Liter. That, right there is 300% difference.

Ilford stop has much less capacity than Kodak.

One 3L bath Ilford stop bath basically lasts me one to two darkroom sessions (30 to 60 8x10FB prints) while Kodak 3L bath lasts at least 5 darkroom sessions (150 8x10 fb prints).

One kodak bottle basically lasts 50 darkroom sessions.

One ilford bottle basically lasts anywhere from 3 to 7 darkroom sessions.

This makes the ilford stop bath the most expensive chemical, effectively more expensive than developer + fixer combined. That is ridiculous.

A proper price to pay for a 500ml ilford stop bottle would be Maximum 1.25$.

grat · May 24, 2022

MrFus said:
It's crazy, you can make 8 gallons (30 liters) of Kodak Stop for $6.49... Paterson tanks use 500ml for roll of 120, I only shoot one roll each week! It is going to last me foreveeeeerrrrr!! Hahahahaha....

Now I only need to find someone who sell it locally or some retailer that can ship it to Florida!

Unique Photo will ship it, but their shipping cost is about 1.5x the cost of the stop bath.

Freestyle will also ship, but their shipping tends to be worse (at least, to Florida).

Or, you could just buy a pound or two of citric acid and make your own stop bath for the next decade.

MrFus · May 24, 2022

grat said:
Unique Photo will ship it, but their shipping cost is about 1.5x the cost of the stop bath.

Freestyle will also ship, but their shipping tends to be worse (at least, to Florida).

Or, you could just buy a pound or two of citric acid and make your own stop bath for the next decade.

Yes, it's like +13 dollars for shipping in a $7 item... As far as I know on my city there is not one single retailer who sells neither film, chemicals or anything darkroom related!

But there are like 100 bars who will provide you with a fine selection of beers!!!

AgX · May 24, 2022

MrFus said:
As far as I know on my city there is not one single retailer who sells neither film, chemicals or anything darkroom related!

This applies to nearly all of us. But... acetic acid you should be able to get from around next corner. Problem solved...

logan2z · May 24, 2022

MrFus said:
Now I only need to find someone who sell it locally or some retailer that can ship it to Florida!

It looks like Midwest photo will ship it:

Mpex

Midwest Photo

mpex.com

Nicholas Lindan · May 24, 2022

I think the cheapest stop bath method is to start with glacial acetic acid. I mix it down to a 28% 'stock' solution with a wee dram of indicator stop bath, and then dilute for the stop bath concentration.

I find there is way too much indicator in Kodak's product - it seems Kodak wants the stuff to turn black under safelight illumination when it expires. I turn on the lights after each print to see how it came out as it floats in the fixer; a lack of the light yellow color to the stop bath is easy to spot.

IIRC buying the indicator by itself was more expensive than using Kodak's indicator bath.

AgX · May 24, 2022

Glacial acetic acid (100% Acetic acid) already is a quite nasty stuff. One may consider what (if any) effective benefits it has over readily available Acetic acid of lower concentration.

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