Fixing regime

[Jarvman]

Hi, I have some sodium thiosuphate from silverprint and I'm not sure what quantities I should dilute it with a litre of water. I added 2 tablespoons to 1 litre of water last night. When it came to bleaching and toning the sepia never worked. Obviously I had mixed it up too strong and overfixed or inadequately hypo cleared and washed. Am I mixing it up too strong? This is what the website says...


"The raw fixing salt, recommended for various processes, particularly as the final bath in a 2-bath fixing system prior to toning. The chemical we normally stock is the more pure anhydrous form, which carries dissolves giving a solution of approximately double the strength of the crystals. A recipe may require conversion of the required weight, as many formulae specify crystalline, and the ratio is 1 part anhydrous to 1.6 parts crystalline."

 

[Anon Ymous]

Sorry but, what do you mean "When it came to bleaching and toning the sepia never worked. Obviously I had mixed it up too strong and overfixed or inadequately hypo cleared and washed"? Sodium thiosulphate is just the plain fixing salt. If using the pentahydrate, about 250g/l is used, if using the anhydrous form, about 160g/l is the equivalent. It will make standard, non rapid fixer and if you don't add some sodium sulphite, it will have poor keeping characteristics.

 

[Jarvman]

Sorry but, what do you mean "When it came to bleaching and toning the sepia never worked. Obviously I had mixed it up too strong and overfixed or inadequately hypo cleared and washed"? Sodium thiosulphate is just the plain fixing salt. If using the pentahydrate, about 250g/l is used, if using the anhydrous form, about 160g/l is the equivalent. It will make standard, non rapid fixer and if you don't add some sodium sulphite, it will have poor keeping characteristics.

I mean there was irreversible bleaching. The tones never came back as sepia. I couldn't have mixed it up very strong seeing as 2 tablespoons is about 20g right? So it couldn't have been overfixed, probably inadequately washed then. Thanks for the quantities. How much sodium sulphite would you add per litre? I need to get some decent scales sharpish.

 

[Anon Ymous]

Sodium thiosulphate isn't used in any stage of sepia toning. The bleaching stage is a potassium ferricyanide and potassium bromide solution. After that, you wash the print and then immerse it in the toning bath. It doesn't involve a fixing bath at any stage. If you fixed after bleaching, losing the image is absolutely normal.

 

[Jarvman]

No, but according to what I've read bleach will combine with fixer left in the paper and cause irreversible bleaching that cannot be recovered by the toner. Hence me being worried about overfixing, but its down to improper washing I think. I've just read Ilford's guide to fixing that suggests two baths of hypam 1+4 each for a minute. What is the formula if I want to make a litre of my own rapid fix? I also have a kilo of ammonium thiosulphate. Also, how does it work if you're using rapid fix for bath one and hypo for bath two? What happens when you come to use the second bath as the replacement for the first bath? They'll be swapping places then.

 

[Tom Kershaw]

No, but according to what I've read bleach will combine with fixer left in the paper and cause irreversible bleaching that cannot be recovered by the toner. Hence me being worried about overfixing, but its down to improper washing I think. I've just read Ilford's guide to fixing that suggests two baths of hypam 1+4 each for a minute. What is the formula if I want to make a litre of my own rapid fix? I also have a kilo of ammonium thiosulphate. Also, how does it work if you're using rapid fix for bath one and hypo for bath two? What happens when you come to use the second bath as the replacement for the first bath? They'll be swapping places then.

You will probably find that rapid fixer is more economical to buy rather than mix yourself.

e.g: http://www.ag-photographic.co.uk/kodak-unifix-5l-584-p.asp

Tom

 

[Rich Ullsmith]

Is there any chance that the problem is with your sepia toner? It seems unlikely that there would be enough fixer left in the fibers to cause what you are describing, particularly after 2-bath fix, hypoclear and wash.

Also, your bleach had a halogen in it, such as bromide or chloride, right?

 

[Thomas Bertilsson]

Also, your bleach had a halogen in it, such as bromide or chloride, right?

That was my thought also. The bleach used with toners has bromide in it so that you actually can re-develop the image.

 

[Jarvman]

Its definitely down to my fix and washing. The bleach I used was part of the fotospeed sepia toning kit. I made two other prints the following day and used fresh fix and hypo clear and a longer wash before and after bleaching and they toned fine. I'm only just starting to get disciplined in the darkroom now! After buying a print washer and a bunch of amber bottles, dedicated trays and labeling everything in sight. I'm going to stop re-using the 5 litre vat of spent fix as I have for so long. What would you imagine the capacity is of a two bath process, both hypam 1+9 in terms of 12x16" fibre based prints. 15-20? and while we're on the subject, what are the recipies you use for making up your own bleach and sepia toner.

 

[Anon Ymous]

Regarding bleach and sepia toner, there are various recipies and some can be found here and here. Just a warning though, careful with the sodium hydroxide and how you make the solution!

 

[Thomas Bertilsson]

I'm just glad you got it figured out. When it comes to fixer and capacity I take no chances. I use a two fixer regimen where I mix up 2L Ilford Hypam at 1+9 every printing session. I use that as my second fixing bath. When I'm done with my printing session I pour that into the bottle that has the first fixing bath stored in it. It is a gallon amber jar, so it gets 2L of 'so so' fresh fixer poured into it after each printing session. Then I top off that jar with whatever I can fit in from the remains of the first fixer bath and discard the rest.
Then I keep going like that forever.
I use 200ml Hypam concentrate per session, basically, and haven't had a problem so far. The toning is always even and complete; no traces of contamination at all. I wash for one hour before I start toning. I use a Kodak tray siphon and they do a good job. I have a print washer too, but it's not as effective as the siphon.

With toning I just buy the Kodak Sepia or Sepia II kits. They are so inexpensive that I don't bother to mix it myself.

 

[Jarvman]

Cheers Thomas, sound advice. I've got one question instead of starting a whole new thread for it. I got the darkroom cookbook the other day and I'm a bit confused by the directions in it. For example...

Ammonium thiosulfate, 57-60% solution, 800ml
Sodium sulphite, 60g
sodium metaborate 5g
water to make 1 litre

is it correct you start with 800ml of the ammonium thiosulfate solution, add the other ingredients and then top it up with 200ml of water to make a litre in total? 'Water to make 1 litre' doesn't mean adding a litre of water on top of the 800ml you already have right? Ta

 

[snallan]

...
Ammonium thiosulfate, 57-60% solution, 800ml
Sodium sulphite, 60g
sodium metaborate 5g
water to make 1 litre

is it correct you start with 800ml of the ammonium thiosulfate solution, add the other ingredients and then top it up with 200ml of water to make a litre in total? 'Water to make 1 litre' doesn't mean adding a litre of water on top of the 800ml you already have right? Ta

That's right, dissolve the rest of the ingredients in the thiosulphate solution, and then make up to 1 litre (rather than add 200 ml of water, which will take you slightly over a litre).

Where I am it is easier to get hold of the ammonium thiosulphate as a powder. So I just buy 500 g of the thiosulphate, dissolve in 700 ml of water (it dissolves really easily, even in cold water), add the rest and make up. (The 60% solution gives you around 480 g of thiosulphate, so mine is very slightly stronger, but well within the normal working concentration range for ammonium thiosulphate, and saves having odd dregs lying around!)