TF 3 Fixer

[Raffay]

Hello, I am planning On making TF 3 Rapid Fixer as I am not very satisfied with plain hypo although I think it should work fine also. But that's not I want to talk about here, I just want to get some clarifications on the formula. Here is the formula:

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TF-3

Alkaline fix for use with PMK and other processes

Ammonium thiosulfate (58-60%)800ml
Sodium Sulfite (anhydrous)60 g
Sodium Metaborate5 g
Distilled water to make1L
Mixing instructions: Add chemicals in specified sequence.

Dilution: 1+4

Notes: Fix for 3x clearing time. This formula is faster than older hypo-based fixers, but takes longer than an acid-based fixer.

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I am little confused about ammonium thiosulfate, when I searched it on google Wikipedia defines it as "ammonium thiosulfate (ammonium thiosulphate in British English) is an inorganic compound. It is white crystalline solid with ammonia odor, readily soluble in water, slightly soluble in acetone and insoluble in ethanol and diethyl ether.[1]". So from this definition it seems that it will be in solid form but the formula sates in ml, hence my confusion.

Cheers
Raffay

[Roger Thoms]

Here's a thread on APUG that might help. http://www.apug.org/forums/forum37/83154-ammonium-thiosulfate.html

Roger

[Raffay]

Thanks Roger, what I want to know is that ammonium thiosulfate is available in liquid as well as crystal form, locally i am only getting it in crystallised form so I am little confused how to interpret the formula that is given in ml rather than grams.

[tgtaylor]

Raffay,

An x% of Y solution means that for every 100mL of water there are x grams of Y in it.

Thomas

[Raffay]

Raffay,

An x% of Y solution means that for every 100mL of water there are x grams of Y in it.

Thomas

So in this case 60% 800ml means 480 grams, right? If not please excuse my maths i am pretty bad at it :)

Cheers
Raffay

[Raffay]

So if we're to make a litre of stock solution of TF-3, I should start with 800ml of water ( what temp?) add 480 grams of ammonium that's 60%, then add sodium sulphite 60 grams, then sodium metaborate 5 grams and finally add 200ml to make one litre. Then make working solution by taking one part stock and 4 parts water...correct? Can I reuse the working solution or do i need to throw it away each time?

Cheers
Raffay

[tgtaylor]

Right.

[Bob Farr]

Now I'm confused??

If the final volume is 1000ml then all calculations should be for this amount instead of 800ml??

Bob

[Raffay]

I am more confused now :) but why does the formula says (58-60%)800ml and then on step four it says distilled water to make 1L

[Raffay]

So if we're to make a litre of stock solution of TF-3, I should start with 800ml of water ( what temp?) Cadd 480 grams of ammonium that's 60%, then add sodium sulphite 60 grams, then sodium metaborate 5 grams and finally add 200ml to make one litre. Then make working solution by taking one part stock and 4 parts water...correct? Can I reuse the working solution or do i need to throw it away each time?

Cheers
Raffay

Can someone please verify this, also the reuse part.

Thanks
Raffay

[Raffay]

Please clarify

[N Dhananjay]

A 60% solution means 60 gms in every 100ml. So for 800ml, you would need 60 x 8 = 480gms. So to make you stock solution of the fixer, start with about 500 ml and dissolve 480 gms in it and add water to bring it to 800ml. Add the remaining chemicals (sulfite and metaborate) and add water to bring it to 1 L. This is your stock solution of the fixer and you will dilute this 1+4 to make up your working solution (e.g., 200ml stock + 800ml water to make 1L of working solution fixer). Hope that helps. Cheers, DJ

[Raffay]

A 60% solution means 60 gms in every 100ml. So for 800ml, you would need 60 x 8 = 480gms. So to make you stock solution of the fixer, start with about 500 ml and dissolve 480 gms in it and add water to bring it to 800ml. Add the remaining chemicals (sulfite and metaborate) and add water to bring it to 1 L. This is your stock solution of the fixer and you will dilute this 1+4 to make up your working solution (e.g., 200ml stock + 800ml water to make 1L of working solution fixer). Hope that helps. Cheers, DJ

Thank you, one more clarification. Can I reuse the working solution or because I am mostly developing one sheet per week, and if I cannot reuse the working solution then the stock will only fix a few sheets and it will be very expensive.

Cheers
Raffay

[N Dhananjay]

Can someone please verify this, also the reuse part.

Thanks
Raffay

As far as reusing, look up the capacity and keep a track of how many sheets of film/paper you run through the working solution. Or you can purchase or make a hypo check solution. Edwal used to make one (still do?), where you add 2 drops and if a white precipitate formed, you had to dump the fixer.
Cheers, DJ

[Raffay]

Thanks

[Raffay]

Can you check the picture I posted today under thread named fixer Color in the darkroom forum and give me your feedback. I would really appreciate that

[Bruce Osgood]

I think you may be confusing the issue.

Ammonium thiosulfate (58-60%)800ml is two distinct items.

Ammonium thiosulfate (58-60%) is a liquid that can be purchased from the Formulary for about $10 a liter. 800 mL is the amount to be used in the formula.

[Doremus Scudder]

I think you may be confusing the issue.

Ammonium thiosulfate (58-60%)800ml is two distinct items.

Ammonium thiosulfate (58-60%) is a liquid that can be purchased from the Formulary for about $10 a liter. 800 mL is the amount to be used in the formula.


Many, if not most, formulas for ammonium thiosulfate fixers assume that the user is mixing from a 60% liquid stock solution of ammonium thiosulfate. This is readily available in the States and Europe and keeps well. I believe there are some problems sourcing and/or storing the dry chemical that make using the saturated solution more practical in most cases.

That said, I know of some who use the dry ammonium thiosulfate, which is apparently what the OP has access to. In that case, one needs to find the correct amount of the dry chemical (which has been done here and is 480g) to use in the formula.

Raffay, TF-3 should be similar to other fixers of this type, so you should be able to reuse it until capacity is reached. Here is the relevant info for TF-4:

"CAPACITY
The capacity of TF-4 is about 30 8x10 prints of fiber-based paper, 60 8x10 prints of resin coated paper, per liter of working solution. Some people are fixing many more sheets of paper than stated here. Do your own testing for your maximum.
For film the capacity is 15-20 rolls of Film per liter of working solution."

I would suggest the following:

For film, do a clip test in fresh fixer to establish your clearing time. Do a clip test subsequently for each batch of film. Fix for a minimum of 2x the clearing time (I like 3x). Discard the fixer when the clearing time is 2x that in fresh fixer.

For fiber-base prints, use two-bath fixing and base capacity on 35 8x10 prints per liter of bath one. Test for residual silver and hypo to establish your own parameters

Best,

Doremus