Kalogen formula ?

[ruilourosa]

it says: you have: potassium hidroxide, the formula specifies: sodium hidroxide, multiply the specified amount by: 0.72, quoting dignan, but cookbook is the same...

 

[Steve Goldstein]

Multiply by 0.72 to convert weight of KOH to weight of NaOH, divide by 0.72 to go the other way.

22.5 / 0.72 = 31.25 which is basically the same as Raghu's result (31.5).

The ratio of molecular weights is 0.7128 (NaOH weighs less) so if you have KOH you need to use more to get the same amount of hydroxide ion, which is what does the work.

Getting precise weights can be a challenge because both chemicals are hygroscopic.

 

[ruilourosa]

 

[ruilourosa]

 

[Alan Johnson]

Both tables are wrong. For this conversion you need the same concentration of OH- ions and to get this multiply the weight of sodium hydroxide specified by 56/40.

 

[ruilourosa]

Thanks!!!

 

[ruilourosa]

i have been checking in other sources and some are correct, but darkroom cookbook has it wrong in the two editions i have...Grant Haist quoting Hans Windish in the first volume o modern photographic processing, has a correct equivalency table!

 

[ruilourosa]

 

[mohmad khatab]

Yes.

1 mole of NaOH = 40 g of NaOH
Therefore, 22.5 g of NaOH = 22.5/40 = 0.5625 mole of NaOH.

You want to substitute 0.5625 mole of NaOH by 0.5625 mole of KOH in the Kalogen formula.

But 1 mole of KOH = 56 g of KOH
Therefore, 0.5625 mole of KOH = 0.5625 * 56 = 31.5 g of KOH.

You need to use 31.5 g of KOH as substitute for 22.5g of NaOH.

I wanted to make an inquiry.
What if you prepared this developer in propylene glycol instead of water,,
Would this be possible?
The idea that occupies me is to extend the life of the developer as long as possible.
In fact, I prepared this developer a year ago, and in fact, it has been completely successful throughout this year,,
But during the last two months, about a quarter of a liter remained, and it was getting darker day by day.
Although it is getting thicker, I filter it with a piece of cotton, and it still works very tolerably,
But I hoped that the developer would retain its purity and all its vitality for as long as possible.
Does this idea seem reasonable and logical, or is it an insignificant idea?

 

[John Wiegerink]

I wanted to make an inquiry.
What if you prepared this developer in propylene glycol instead of water,,
Would this be possible?
The idea that occupies me is to extend the life of the developer as long as possible.
In fact, I prepared this developer a year ago, and in fact, it has been completely successful throughout this year,,
But during the last two months, about a quarter of a liter remained, and it was getting darker day by day.
Although it is getting thicker, I filter it with a piece of cotton, and it still works very tolerably,
But I hoped that the developer would retain its purity and all its vitality for as long as possible.
Does this idea seem reasonable and logical, or is it an insignificant idea?

Are you going to live to be 127 years old, or maybe more? You will get all the shelf life you need just mixing it as the regular formula. I have a partial bottle that is slightly off color, but works just like it was mixed yesterday. I made that batch in Jan. or Feb. of 2016 and never took any precaution as to oxidation in the half full bottle either. I'd say mixing it with glycol is a waste of good propylene glycol and time. Very good developer that mimics Rodinal in almost every way. Oh, and it's also much easier to make. Just my 2 cents worth. JohnW

 

[Raghu Kuvempunagar]

In fact, I prepared this developer a year ago, and in fact, it has been completely successful throughout this year,,
But during the last two months, about a quarter of a liter remained, and it was getting darker day by day.
Although it is getting thicker, I filter it with a piece of cotton, and it still works very tolerably,
But I hoped that the developer would retain its purity and all its vitality for as long as possible.

Store it full in several tightly capped bottles. For instance, if you make 1 liter of the stock solution, you can store it in 1 x 500 ml, 2 x 200 ml and 1 x 100ml bottles. Keep another 1 x 100ml bottle as spare. First use the stock solution in the 100ml bottle - all other bottles are full till this 100ml bottle becomes empty. Then distribute the contents of 200ml bottle to the two 100ml bottles. And so on. The idea is to keep all bottles with stock solution except the smallest one full throughout.

Keep the bottles in a cool dark place.

 

[mohmad khatab]

Are you going to live to be 127 years old,

Store it full in several tightly capped bottles. For instance, if you make 1 liter of the stock solution, you can store it in 1 x 500 ml, 2 x 200 ml and 1 x 100ml bottles. Keep another 1 x 100ml bottle as spare. First use the stock solution in the 100ml bottle - all other bottles are full till this 100ml bottle becomes empty. Then distribute the contents of 200ml bottle to the two 100ml bottles. And so on. The idea is to keep all bottles with stock solution except the smallest one full throughout.

Keep the bottles in a cool dark place.

No, brother, I have absolutely no certainty that I will live the next hour.
I did not expect that I would be criticized for simply putting forward such an idea in good faith. This forum is an arena for proposed thinking and for putting forward ideas and discussing them, and this is the ultimate goal for which it was established.
Propolis glycol prices in Egypt are very cheap (and I don't know why) you can consider that it is free in Egypt.
Do you really use it the same times as Rodinal?

- It's not about me. I am not the one to use it.
I sent a 50ml sample from this developer to the analog photographers community in Tunisia, they are very impressed with the results and would like to get one liter.
The bottle will be shipped with the luggage bag, and of course it will be almost impossible for the bottle to be glass so as not to be broken.
(The photographer is the girl who is going to travel with that bottle), maybe she will split that amount and sell it to the young photographers there or something like that (in order to make a profit),, I'm not really sure..
But they were always inquiring about the life span of this developer and very much hoped that the life span would be long for more than a year.

It's okay, I can prepare it with water and sell it as it is, but it was just an idea that came to my mind, so I wanted to inquire only about that idea in principle (is it a good and logical idea) from a scientific point of view or not?

 

[Raghu Kuvempunagar]

I thought I replied in good faith giving you a practical solution for long shelf life.

It's not feasible to synthesise a glycol based Kalogen concentrate as Metol, Sulphite and Bromide are not very soluble in glycol.

 

[ruilourosa]

Times for kalogen 1+50 are close to d-76 stock as i have been reading.
I tryed to mix kalogen with potassium hidroxide and it does not work... you have to had a substancial more amount of hidroxide to the precipitated solution to dissolve, maybe offsetting the equilibrium. After i mixed it with sodium and it worked very well. I have not tested fully but negs seem regular with d-76 times and harman 100 iso film (kentmere)

i would like to discuss other dilutions and times if you have other experiences

Thanks!!!