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  #1  
Old 18th January 2022, 05:29 PM
big paul big paul is offline
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Default stop bath

I have a bag of Citric Acid Crystals ,food grade ,can I use it as stop bath and if so how do I use it .
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  #2  
Old 18th January 2022, 05:54 PM
Lostlabours Lostlabours is offline
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Yes, ideally you need a 2% solution, so 20gms per litre.

Ian
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Old 19th January 2022, 04:25 PM
Terry S Terry S is offline
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And use the solution fresh at each session. It's cheap enough to do this, but also apparently mold appears in it quite quickly.

I haven't used it myself yet, but I've got some if the need arises.

Terry S
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Old 20th January 2022, 09:30 AM
big paul big paul is offline
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Thanks for the replies folks, So can I use it with film as well .I will try it soon ,But it feels a bit strange
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Old 22nd January 2022, 05:06 PM
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Ilfostop is essentially citric acid with an indicator dye added so no worries using it with film.

It may have a fungicide added also (or possibly the dye serves that purpose too?) - either way, Terry is correct about fungus' addiction to citric acid - they love the stuff! OK I exaggerate a little, but it will develop growth much faster than acetic acid based stop but has the massive advantage (for me) that citric acid stop is odourless.
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Old 22nd January 2022, 06:01 PM
MikeHeller MikeHeller is offline
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Well. you learn things on this forum! I never knew that Ilfostop was citric acid based. I have stored it in a glass bottle (for negative development) and my toaster for months and never seen any fungal growth.

Mike
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Old 22nd January 2022, 06:34 PM
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My interest piqued, I requested Mr. Google to direct me to the current whereabouts of the Safety Data Sheet for Ilfostop where I could peruse its contents at my leisure. The aforementioned document informs me that it is composed of 10-30% citric acid and 1-5% of a substance named 2-PHENOXYETHANOL which, Mr. Google informs me upon my further enquiry, is a bactericide. The SDS does not list the pH-sensitive dye which suggests it is considered non-toxic(ish) by Her Majesty's Inspector of Things-That-Can-Kill-You-Without-You-Realising.


(It's been a tiring few weeks ...)
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Old 24th January 2022, 11:25 AM
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Martin Aislabie Martin Aislabie is offline
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Quote:
Originally Posted by Bob View Post
My interest piqued, I requested Mr. Google to direct me to the current whereabouts of the Safety Data Sheet for Ilfostop where I could peruse its contents at my leisure. The aforementioned document informs me that it is composed of 10-30% citric acid and 1-5% of a substance named 2-PHENOXYETHANOL which, Mr. Google informs me upon my further enquiry, is a bactericide. The SDS does not list the pH-sensitive dye which suggests it is considered non-toxic(ish) by Her Majesty's Inspector of Things-That-Can-Kill-You-Without-You-Realising.


(It's been a tiring few weeks ...)
That explains things Bob.

I have started retaining my dilute Stop Bath from printing sessions, in the name of economy and the environment, for up to 5 print sessions.

I have not found any "freinds" growing in the solution, even through I may store it for perhaps up to 2 weeks in total.

I used to dump my stop bath at the end of each session because even concentrated citric stop bath in the bottle used to need filtering because of growths.

Martin
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Old 24th January 2022, 11:40 AM
Terry S Terry S is offline
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I made up some citric acid and water only solution last year for some experiment or other.

In between sessions, I kept it in a dark brown bottle in the bathroom, so it was at room temperature.

I got some mould growing on it in the bottle, but if I recall correctly, it took at least a couple of months for this to happen.

I do wonder if the concentration of the solution makes a difference in how long it takes for mould to appear? But it definitely shows that one can re-bottle it and use it on a number of occasions, before dumping it.

Terry S
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  #10  
Old 24th January 2022, 01:37 PM
Nat Polton Nat Polton is offline
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I used to use citric acid when making homemade wines.
The last packet that I bought was from Boots the Chemist.
When I asked the assistant where I would find it she went away to ask the pharmacist. Then followed a lot of peeping around the corner at me by the chemist and a discussion going on between them.
Eventually he emerged from his hideaway and courteously grilled me as to what it was for and how it affected the wine making.
He eventually explained that it is used in preparing illegal substances by drug addicts, and that was what all the quizzing was about.
I must have looked respectable as he eventually supplied me with it.
So do not be surprised if you get quizzed when buying some in the future.

Cheers.
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