Ilford Rapid Fixer dilution

[gfevan]

Hi all,

I am not sure about the dilution needed for RC paper.
The label on the bottle says 1+4 or 1+9.
Actually, there is a big different between 1+4 and 1+9.
Usually I use to mix 1L of fixer (100fixer+900water) before my printing section. Is it correct? Or should I use a stronger dilution?

Thanks

http://www.flickr.com/photos/gfevan/

 

[Anon Ymous]

It's absolutely fine at 1+9 and in case you didn't know it, the solution can be reused. I say this because you say that you mix 1L... before your printing session. Especially for RC papers, the solution's capacity is quite high, much better than that for FB. Get the pdf here.

 

[gfevan]

Thanks Anon!
I reuse my mixed fixer only if my next session is within 1 week. According to the label the mixed and used fixer has a life of 7 days.

 

[Anon Ymous]

7 days is the working solution's life if left in the open tray. Put it back in a bottle and you can reuse it for months. No need to be wasteful. Look at the last page once more.

 

[dancqu]

The label on the bottle says 1+4 or 1+9.
Actually, there is a big different between 1+4 and 1+9.
http://www.flickr.com/photos/gfevan/

There is supposed to be a big difference. Prints should
not be exposed to the high silver loads possible with film
in film strength fixer.

If one wishes to keep fixer silver loads on a volumetric
basis to levels safe for prints use the 1:9 dilution. Ilford
allows 20 8x10s per liter at 1:9. At 1:4 the capacity ups
to 40 8x10s per liter. The two capacities are the fixer's
chemical capacity for dissolving silver.

On a Volumetric basis prints are not to be subjected
to the high silver load possible with film strength. So
for prints, 1:9 and 1/2 the capacity PER LITER. Dan

 

[Anon Ymous]

There is supposed to be a big difference. Prints should
not be exposed to the high silver loads possible with film
in film strength fixer...

While what you say is true, the question was about RC paper. The polyethylene layer protects the base, therefore allowing much higher silver levels, although not as high as film.

 

[gfevan]

How many 24x30(9x12) prints can I fix in 1L mixed solution?

 

[Anon Ymous]

How many 24x30(9x12) prints can I fix in 1L mixed solution?

1L of mixed solution is capable of fixing up to 4 square meters of RC paper, so a calculation is all you need to do for whatever size. Dilution is irrelevant, since it is the silver content of the solution that matters. Page 2 of the aforementioned pdf has the same figures for 1+4 (film strength) and 1+9 (paper strength). Logically, and if silver content was irrelevant, the 1+4 dilution would be twice as capable. That's not true though.

You can see that they state that:

a) Film can be fixed in a solution with at most 8-10 g of silver/L.
b) RC paper can be fixed in a solution with at most 4-6 g of silver/L.
c) FB paper can be fixed in a solution with at most 2 g of silver/L.
d) If using FB and you want top quality, 0,5 g of silver/L.

More specifically, they say that 40 sheets of 20x25cm (8x10in), or 2 square meters FB paper can be fixed with 1L of solution. Assuming that you reach 2g/L at that point and if both paper types have the same silver content, then they have chosen 4 g/L as the margin for RC paper.

 

[dancqu]

RC or FB 1:9 the Better Dilution

While what you say is true, the question was about RC paper.
The polyethylene layer protects the base, therefore allowing
much higher silver levels, although not as high as film.

I did dwell upon FB didn't I. OK RC. At 1:4 the capacity of
one liter of working strength is 80 8x10s. Even with a huge
margin of safety, say 1/2 that, how many are likely to put
40 through in one session? At 1:9 and the same safety
margin 20 prints can be fixed. Dan