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/forum37/8...iosulfate.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