potassium bromide as anti-fog for old film

[Aurora]

I bought this
www.freestylephoto.biz/100930-Formulary-Potassium-Bromide....

I have tried google around and all of that, without too much success.
I bought some (not all of the same batch) old expired films, such as Svema 64, Svema MZ-3, Tasma Kazan
and think they are
fog bound. So I purchased some potassium bromide in order to mix with my developer.
I have HC-110, Rodinal and Rodinal One shot Special.
I can also get D-76 and Ilfotec HC here in Iceland.
So in case I could use the potassium bromide how should I dilute and how much of it should I use.
It comes in crystals.
I could mix up like a 2%solution, and then use for example 2 ml of that.
Anyone has any experience of this?

 

[maddoc]

I only use 1% KBR(aquos) solution when developing films in Caffenol and I use a concentration of 1 g per liter. Have a look also here:

http://caffenol.blogspot.jp/2010/05/caffenol-c-h-highspeed.html

 

[Roger Hicks]

Expect significantly lowered film speeds too: maybe 1 stop.

Cheers,

R.

 

[ChrisLivsey]

You have had some excellent replies to this question on APUG is there anything we could add ?

 

[Fotohuis]

You can use Benzotriazole 0,1% or Potassiumbromide 0,5%-1,0% for this.
HC-110 is already containing Benzotriazole so I would try dilution B (1+31) first on old expired films.
Expect speed loss of at least 1F stop as already told.

1% KBr = 10g/ltr. 1g/ltr. = 0,1%

When using Benzotriazole you can dissolve it in alcohol (e.g. IPA) 1g/100ml which is 1%. This is a stable solution.

 

[Aurora]

Thanks Fotohuis, this is such a concrete answer.
With all the chemistry I can get slightly confused.
Just to be sure.
To make a 1% KBr working solution in order to add with HC-110
is this correct:
Make the correct working solution of HC-110 B (1+31)
Then make a 1% solution of KBR = 10gr potassium bromide diluted in 1000 ml water.
If my tank needs 600 ml
I add 3 ml (of that solution) in order to have
0,5% of KBr or 6ml if I want a 1% KBr.

I don´t really get the following:
1% KBr = 10g/ltr. 1g/ltr. = 0,1%

 

[Fotohuis]

I don´t really get the following:
1% KBr = 10g/ltr. 1g/ltr. = 0,1%

This has do to with:

I only use 1% KBR(aquos) solution when developing films in Caffenol and I use a concentration of 1 g per liter.

Make the correct working solution of HC-110 B (1+31)

You do not have to add anything to HC-110 because it is already containing Benzotriazole.

For any developer without Benzotriazole OR KBr you can add 0,1% Benzotriazole (10ml of above solution in 1 ltr. developer) OR 0,5% KBr (5g KBr in 1 ltr. developer) to suppress the fog.

 

[Rangefinderfreak]

This has do to with:



You do not have to add anything to HC-110 because it is already containing Benzotriazole.

For any developer without Benzotriazole OR KBr you can add 0,1% Benzotriazole (10ml of above solution in 1 ltr. developer) OR 0,5% KBr (5g KBr in 1 ltr. developer) to suppress the fog.

Robert: So THIS is the reason my Rodinal/HC 110 mix works so well... It has the fog fighting qualities because of benzotriazole already built in...?

 

[Aurora]

Robert: So THIS is the reason my Rodinal/HC 110 mix works so well... It has the fog fighting qualities because of benzotriazole already built in...?

How do you mix it if you want to use a combo?
Do you mainly use it for stand dev?
I have an Orwo NP20 film that I would love to try in that combo.

 

[Aurora]

Fotohuis
So you take 1ml for example of the solution you have already mixed?
When you need to use it.

 

[Aurora]

Here is the info I have gathered on the HC-110/Rodinal Combo in case someone is interested.
Using 1+200 of HC-110 I added it to some Rodinal 1+100 semi-stand, which is shaken at 30:00 and let stand a total time of 60:00...
Needless to say, the negatives were nice, sharp, and surprisingly kept fine grain!

1+1:200
Try 30 sec initial agitation gentle, then leave untouched for 60 min. You could do one gentle agitation at 30 min

HC-110 30ML AND RODINAL 30 ML TO 2 LITERS
7 MIN NORMAL AGITATION - ASA400
5 MIN NORMAL AGITATION 200 ASA

1 ml HC-110
3 Rodinal
400 ml water
1+3+400

3ml HC
3ml Rodinal
water to cover a 2 roll tank
a little less than 1:100 dilution
30s initial agitation
3 inversions every 20 min
total time 60 min
Box speed

I also read this one - although with Xtol
http://figitalrevolution.com/2009/08/10/stand-development-part-3/

 

[Rangefinderfreak]

Well, I am not that "scientific" I just go with the 30+30 mix, replinsh it when I feel like and just enjoy the results...http://www.flickr.com/photos/40146285@N08/7157230957/

 

[Aurora]

Well, I am not that "scientific" I just go with the 30+30 mix, replinsh it when I feel like and just enjoy the results...http://www.flickr.com/photos/40146285@N08/7157230957/

I guess you know what you were doing 🙂

 

[Aurora]

result of potassium bromide

result of potassium bromide

Just thought I should post my result, with the potassium bromide.
Think it is still heavily fogged and I thin they photos are over exposed, shot it at 50 ASA.
It was an Orwo NP20 film.
Rodinal 12min
20C
Added 1 ml of a 2% potassium bromide solution. Think I should have tripled that.
http://www.flickr.com/photos/104979973@N04/tags/orwonp20/