What is the difference in fixers???

[stradibarrius]

I know there is consideralble difference in developers but is one fixer basically the same as another?

I have only used kodak professional powder fixer up to now.

 

[brucemuir]

I'm not a chemist but will offer what little I do know.

Basically there are 2 types.
1. Sodium Thiosulfate based
2.Ammonium thiosulfate based

Sodium types are much slower to work and can come in a powder like the Kodak envelope that you mix yourself.

Ammonium types are the liquid types that are usually called "Rapid" fixers and come in liquid form.

You can add hardener (usually potassium alum)if it is not already present in a rapid type, to either one but the consensus seems to be only older emulsion formulas (efke,foma etc) need hardener these days.

It's never good to generalize on the internet and especially regarding chemistry...

but that is the crux of the biscuit, which is the apostrophe

 

[Casey Kidwell]

From my understanding the differences for black and white chemistry (don't know about color bleach-fix) are:

-Varying fixing time
-Hardener vs no hardener
-effects on staining developers
-ease of mixing
-longevity of working solution
-expense

Personally I only use non-hardening fixers. Makes toning easier and I hate spotting hardened prints.

 

[brucemuir]

btw Strad,
haha I put my line about generalizations before I read your sig.

 

[stradibarrius]

The reason I am asking the question is I am about out of fixer and I was thinking about trying a liquid fixer for the ease of use.
Are there pros and cons of useinf either or is it just a matter of choice? Can liquid fixer be used for paper fixer as well?

 

[glbeas]

Rapid fix, AKA liquid fixer, is actually better for prints because it can be washed out of the paper faster. One part of that is the fix time being reduced also reduces the amount of time the fix has to penetrate the base of tthe paper. Second the ammonium ion washes out faster on it's own.
On top of that you don't need to mix the entire batch at once. With most liquid fixes you can figure the proper ratio and mix only what is needed for the day and toss in the recovery bucket when done.

 

[brucemuir]

Strad,
there also are the TF-4/TF-5 type of fixers that are alkaline and offer shorter times, easier wash, supposedly less odor.
These are liquid concentrate.
An acid stop is not recommended with these but I'm not straight on the specifics.

The only disadvantage to liquid imo is the added shipping costs if you cant buy locally.

 

[hpulley]

Ilford Rapid fixer is used at the same 1+4 concentration for film and paper though a lower concentration 1+9 can be used for paper for more control and to make it go further. I'm told you should keep separate film and paper fixers in working concentrations though I'm not sure why, I guess you end up with different stuff in them. You aren't supposed to add hardeners to Ilford Rapid Fixer. The liquid is quite convenient.

 

[glbeas]

Ilford I'm told you should keep separate film and paper fixers in working concentrations though I'm not sure why, I guess you end up with different stuff in them.

You are right you do wind up with different stuff, the film fix loads up with iodides which can slow down the fixing action which for prints is not good.

 

[brucemuir]

^ I would imagine you would get little paper fibres that stick to your film if you doubled up also.

I've never done it but it sounds like a possibility.

 

[markbarendt]

Barry,

You can also use C-41 fixer in place of B&W fixer.

I bought some TF-5 before I figured that out so it will be a while before I start using it, drat.

 

[fschifano]

OK, there are two forms of thiosulfate commonly used as photographic fixers. The older, more classic if you will, of the two is sodium thiosulfate. The other is ammonium thiosulfate, also known as "rapid" fixer, which works more quickly and has more capacity than the sodium version. Either may be acidic, neutral, or alkaline. If it is an acidic fixer, it may or may not contain an incorporated hardener. Neutral to alkaline fixers will never contain a hardener. There are very few materials or processes in use today that require a hardening fixer, and none in the most commonly used negative and paper processing systems, so chances are that you won't need a hardening fixer. And that's a good thing because neutral to alkaline fixers wash out of papers and films much more quickly than do acid hardening fixers.

You can use the same type of fixer for films and papers, but I would caution you against using fixer that has been used for paper on film and vice versa. There is some evidence that fixers used for film can have a deleterious effect upon the longevity of prints fixed with the same fixer. So say you get some Ilford Rapid fixer. You can use it for both film and prints, but make up separate batches of working solution for each and keep them separate.

BTW, C-41 fixer is perfectly ok for B&W materials. I use it all the time and it's a very good value. Only problem is that you need to buy the concentrate in large quantities. I believe the smallest size Kodak sells now is 5 gallons of concentrate to make 25 gallons of working strength fixer.

 

[nworth]

Fixers are pretty much interchangeable, but there are differences that affect some aspects of performance. The most obvious difference is rapid fixer versus regular fixer. Rapid fixers contain ammonium ion, either as ammonium thiosulfate or another salt, such as ammonium chloride, with sodium thiosulfate; regular fixers generally use sodium thiosulfate. The difference is the amount of time it takes for them to work. Rapid fixers are about twice as fast as comparable regular fixers. Another difference is the pH (acidity or alkalinity) of the fixer. There is quite a range available from moderately alkaline to fairly acid. In general, the alkaline fixers wash out more easily, but they do not do anything to stop development and they are somewhat more prone to stains. Some processes require that the fixer be not too acid, but any of the popular fixers will work well for general use. Another difference is the hardener. Some fixers contain a compound, usually an alum, to harden gelatin. This was once needed to prevent scratches on film and to help release glossy prints from heated metal dryers. It is not so important now that films are superhardened by the manufacturer and ferrotyping is seldom done for glossy prints. Hardening fixers are generally quite acid to prevent the alum from decomposing. All fixers contain sulfites as preservatives, but they may also contain other compounds to help in the fixing process (like thiocyanates) or as pH buffer components (like borates and boric acid). Sometimes theses additional components have other functions as well.

 

[George Collier]

Mentioned in the thread, but not really discussed is alkaline fixer TF4 and TF5 (P-Formulary). I don't know a lot about them other than they don't require an acid stop, are very fast, and wash out more easily than acid fixers. I have used TF4 exclusively, for film and paper for about 2 - 3 years. I use a 2 bath system, half of the recommended time per bath for both film and paper. TF5 is it's replacement, I believe.
It does have an ammonia smell (slight or objectionable depending on your sensitivity), and does cost more to ship, but just the simplification of not needing acetic acid or washing aid made the deal for me. And it's great to have a fiber print completely fixed in one minute for viewing.
You can find a lot more about it by searching this thread for TF4.