Fixer recipes, etc

Claudio Bonavolta wrote:
On 25 juil, 00:28, Larry wrote:
Hello,

I am currently living in a small town with no access to photographic
chemicals. I would like to manufacture my own anyways.....

I need recipes for Fixer and wetting agent...

Thank you in advance to your replies and also, please send the replies
via e-mail

Thanks,

Larry

You can find a scan of Kodak publication J-1 on my site (20 MB file):
http://www.bonavolta.ch/hobby/files/Kodak%20j-1.pdf

There is something wrong with that version of J-1. At least, at the top of
page 39, they leave out the formula for Kodak Stop Bath SB-5, but then
continue how to modify it to make SB-5a.

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Claudio Bonavolta wrote:

Yep, you're right, some lines are missing here !
Kodak SB-5
Water 750 ml
Acetic acid at 28% 32 ml
Sodium sulfate anh. 45 gr
Water to make 1000 ml
Claudio Bonavoltahttp://www.bonavolta.ch-Hide quoted text -
- Show quoted text -
I have to admit that I don't fully understand the role of Sodium
Sulfate in the formula.

It is supposed to minimize gelatin swelling.

Right. Developers, e.g., D-76, have a lot of salts in them (100gm/litre for
D-76), as do fixers. But the typical acetic acid stop bath (e.g. SB-1) have
none. The idea is not to shock the film with this, so they put some sodium
sulfate in there, which is pretty much inactive chemically, but physically
is a salt that keeps the gelatin from swelling and then shrinking again (or
vice-versa, I no longer remember which) when put into the fixer.

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"Jean-David Beyer" wrote in message
newsxBjk.420$rb5.78@trnddc04...
Claudio Bonavolta wrote:

Yep, you're right, some lines are missing here !
Kodak SB-5
Water 750 ml
Acetic acid at 28% 32 ml
Sodium sulfate anh. 45 gr
Water to make 1000 ml
Claudio Bonavoltahttp://www.bonavolta.ch-Hide quoted
text -
- Show quoted text -
I have to admit that I don't fully understand the role
of Sodium
Sulfate in the formula.

It is supposed to minimize gelatin swelling.

Right. Developers, e.g., D-76, have a lot of salts in them
(100gm/litre for
D-76), as do fixers. But the typical acetic acid stop bath
(e.g. SB-1) have
none. The idea is not to shock the film with this, so they
put some sodium
sulfate in there, which is pretty much inactive
chemically, but physically
is a salt that keeps the gelatin from swelling and then
shrinking again (or
vice-versa, I no longer remember which) when put into the
fixer.

--
.~. Jean-David Beyer Registered Linux User
85642.
/V\ PGP-Key: 9A2FC99A Registered Machine
241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 05:30:01 up 8 days, 10:18, 4 users, load average:
4.17, 4.22, 4.17

SB-5 is a double strength stop bath for photo-finishing
use. The sulfate is to minimise swelling as you state. The
original instructions are to leave the film in it for three
minutes, probably in order that the emulsion becomes
saturated with the bath.
Sodium sulfate was an ingredient of many "tropical"
developers and fixing baths for the same reason. Emulsions
were a lot softer in the past. Some current B&W emulsions
are hardened like color film to withstand 100F processing.
Kodak T-Max films are an example.
Another example of a non-swelling bath is Kodak SB-4, a
high temperature stop bath using chrome alum as a hardener:

Kodak SB-4 For Use at 75 to 90F
Water 1.0 liter
Potassium chrome alum 30.0 grams
Sodium sulfate, desiccated 60.0 grams

Agitate films or plates for 30 to 45 seconds after placing
them in the bath and allow them to remain for at least 3
minutes.
At temperatures below 85F rinse films for a 1 or 2 seconds
in water before immercing in the stop bath.


--
---
Richard Knoppow
Los Angeles, CA, USA

Richard Knoppow wrote:

SB-5 is a double strength stop bath for photo-finishing
use. The sulfate is to minimise swelling as you state. The
original instructions are to leave the film in it for three
minutes, probably in order that the emulsion becomes
saturated with the bath.

I think you are mixing up SB-5 and SB-5a.

SB-1
Water 1 Litre
28% Acetic Acid 48.0 ml


SB-5
Water 500 ml
28% Acetic Acid 32 ml
Sodium Sulfate Anh. 45 gm
Water to 1000 ml

SB-5A
28% Acetic Acid 64 ml
(every thing else the same as SB-5)

Sodium sulfate was an ingredient of many "tropical"
developers and fixing baths for the same reason. Emulsions
were a lot softer in the past. Some current B&W emulsions
are hardened like color film to withstand 100F processing.
Kodak T-Max films are an example.

Another example of a non-swelling bath is Kodak SB-4, a
high temperature stop bath using chrome alum as a hardener:

Kodak SB-4 For Use at 75 to 90F
Water 1.0 liter
Potassium chrome alum 30.0 grams
Sodium sulfate, desiccated 60.0 grams

Agitate films or plates for 30 to 45 seconds after placing
them in the bath and allow them to remain for at least 3
minutes.
At temperatures below 85F rinse films for a 1 or 2 seconds
in water before immercing in the stop bath.




--
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"Jean-David Beyer" wrote in message
news:4rOjk.381$wS4.344@trnddc03...
Richard Knoppow wrote:

SB-5 is a double strength stop bath for
photo-finishing
use. The sulfate is to minimise swelling as you state.
The
original instructions are to leave the film in it for
three
minutes, probably in order that the emulsion becomes
saturated with the bath.

I think you are mixing up SB-5 and SB-5a.

SB-1
Water 1 Litre
28% Acetic Acid 48.0 ml


SB-5
Water 500 ml
28% Acetic Acid 32 ml
Sodium Sulfate Anh. 45 gm
Water to 1000 ml

SB-5A
28% Acetic Acid 64 ml
(every thing else the same as SB-5)

Actually what I think happened is my eye skipped over
the last part which was to bring the volume up to 1.0 liter
because SB-5a is not on the page I was looking at. I don't
remember what time of day I posted this but if I was just
home from work I may not have had many brain cells working.


--
---
Richard Knoppow
Los Angeles, CA, USA