Substitution for sodium metaborate in alkaline fixer

[xosni]

I'm trying to make an alkaline fixer from sratch but I'm not able to find sodium metaborate, is there a substitution?

 

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Thanks

[jorge_gasteazoro]

half the amount of Sodium carbonate will do.

[xosni]

Somebody told me that Borax & sodium metaborate ar einterchangeble.

Is it true?

[ted_kaufman]

No, they are not interchangable.

[ryuji_suzuki]

First of all, in fixer formulae, you need to choose acids and bases

carefully. If you look at traditional hardnening fixers, you see

things like boric acid in addition to glacial acetic acid. Those are

the result of seeking thiosulfate compatibility as well as hardner

compatibility, besides other things. In non-hardening formulae,

selection is easier but still a number of things must be considered

besides pH.

 

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If you just want the benefit claimed for TF-{3,4}, try Ilford

Multigrade Fixer (not Universal Fixer) and see if you like

the result. As you might get some idea from one of my earlier

postings here, in my understanding, you get nearly all the

benefit of what's claimed for TF-4 by adjusting the pH to be

anywhere between 6 and 7. Ilford Multigrade Fixer is at about 6.

(Freshly mixed unused solution may be somewhat lower, but it's still

ok.) Sodium metaborate would set the pH higher than this range, and

you will smell ammonia.

 

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If you want to try the published formula, but not so willing to go

through your thinking process, then stick with sodium metaborate.

I do not recommend a quick substitution, even if they are said to work

in most general developer formulae.

[pete_andrews]

Isn't Kodalk available anymore? Kodalk is Sodium Metaborate, by all

accounts. A quick websearch just showed that a company called Bostick

& Sullivan have Sodium Metaborate for sale.<br>Lastly. Alkali Fixers -

why?

[n_dhananjay3]

Hi Pete, alkaline fixers have a couple of uses. Especially popular

with pyro users because acid fixes apparently are not conducive to

the stain. Have also heard arguments for keeping paper processing

alkaline to enable going striaght from fix to Selenium toner (see

www.heylloyd.com and technical section for an interesting paper on

same). Cheers, DJ.

[jorge_gasteazoro]

Pete, Kodalk is not Sodium metaborate, it is if my memorie serves me

right sodium pentaborate decahydrate. As I stated before 1/2 as much

of Sodium Carbonate will work IF it is diluted in an alkaline

solution. Of course if you dilute it in an acid solution then you get

foaming and CO2. Mostly this is used in the little chemistry games

like the volacano etc.