Concentrated long lasting paper developer formula

OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
I just made a liter of concentrated id62 using 150gr of sodium carbonate plus 5gr of potassium hidroxide...
I dos not add benzotriazole as i run out of it.... Just 5 gr of bromide...
Lets see if there is some cristalization... And if it works properly... Im a bit afraid of fog but...
 
Last edited:

grainyvision

Subscriber
Joined
Feb 19, 2018
Messages
695
Location
Denver, Colorado
Format
Multi Format
Why the need to avoid potassium carbonate? I've never seen any highly active (paper) developer of high concentration accomplish it using sodium salts. It seems like a pointless endeavor to save a very small amount of money. It looks like 5lbs(2.2kg) of potassium carbonate is available local to me for $30 while 5lbs of sodium carbonate anhydrous is $20 and sodium carbonate monohydrate (more stable, more commonly specified) is $35. For your example, assuming you're using the more common anhydrous, 150g of sodium carbonate is about 1.415 mols, equivalent to 195.6g potassium carbonate. To make 1L of this like you have, that's a price difference in only carbonate of $2.66 for potassium carbonate vs $1.36 for sodium carbonate. I think the amount of chemistry which must be used in order to figure out a way to make this substitution work would very quickly make the $1.30 of price savings very quickly an irrelevant consideration. If potassium carbonate is especially difficult to affordably find in your locale, then maybe this savings is substantial enough to matter. Also substituting potassium carbonate with a mixture of sodium carbonate and potassium hydroxide is not really equivalent, the potassium hydroxide will not retain as much pH stability. If you have cheap potassium hydroxide available as well as boric acid, you could try to make potassium metaborate which can be relatively easily made in a very concentrated solution exceeding 50% (and equivalent to something like 70% of sodium metaborate due to hydration state). Metaborate solubility is also not affected by glycol like carbonate is, in case you need to use propylene or ethylene glycol for the developing agents. However, there's not too many paper developers that use metaborate without carbonate. I have one formula, but it uses TEA as well which severely limits the solubility of sodium sulfite. One component which doesn't seem to affect solubility of sulfite as much as other things is DMSO. It may be hard to source and tends to make your darkroom smell bad, but is not toxic and somewhat common to find in some regions due to use in veterinary applications. Using DMSO it is possible to make a phenidone solution of 70% concentration or hydroquinone of at least 30% concentration (likely closer to 50%). High concentration might be possible with glycin (if neutralized and using glycol, free base glycin is extremely soluble in glycol), but the most obvious way to achieve it is the much more common phenidone-hydroquinone combination.

I would be interested in a 10ml of concentrate to make 1L of paper developer formula, but I do not expect you could achieve this without some slightly exotic ingredients including potassium sulfite (or potassium metabisulfite and synthesizing in situ)
 
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
Lets see as said by the blind man.

I can have 1 kg for around 1 euro of sodium carbonate mono
Potassium carbonate is 18 times more....

Hidroxides are not buffered, i know... But i am not using it alone....

20 years ago i did made some experiments with sodium and potassium carbonate and hidroxides.
I had a bit of fog issues, solved with benzotriazole...
And... Some cristalization...

I am trying to find a good solution for a school without many resources... So glycin is a no...

Pq or maybe pa dev is going to be the way...
And the most concentrated version possible...
 

tezzasmall

Member
Joined
Dec 29, 2013
Messages
1,137
Location
Southend on Sea Essex UK
Format
Plastic Cameras
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
No cristalization just some sediment i will filter...
I will try 1+9 shortly regarding fog, max density, contrast and tone.

Dissolving 150gr of sodium carbonate was not easy but when i added 5gr of potassium hidroxide the solution cleared.
 

John Wiegerink

Subscriber
Joined
May 29, 2009
Messages
3,681
Location
Lake Station, MI
Format
Multi Format
I heard it this way………”I see said the blind man as he picked up his hammer and saw”.
 

pentaxuser

Member
Joined
May 9, 2005
Messages
20,000
Location
Daventry, No
Format
35mm
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format

pentaxuser

Member
Joined
May 9, 2005
Messages
20,000
Location
Daventry, No
Format
35mm
ruilourosa said:
Theo

The issue is the price of the salts being used, as commented through the thread
Click to expand...
I fear can only wish you well in your attempt to do what you want or need to do as a result of the need for economy of cost, efficacy of the subsequent developer and the necessary concentration

pentaxuser
 

koraks

Moderator
Moderator
Joined
Nov 29, 2018
Messages
23,294
Location
Europe
Format
Multi Format
ruilourosa said:
I can have 1 kg for around 1 euro of sodium carbonate mono
Potassium carbonate is 18 times more....
Click to expand...
Are you sure you can't get a better deal? My preferred store in the netherlands retails pot. carbonate at around €7 for 1kg and €47 for 25kg. They retail to consumers, so these are not b2b wholesale prices or anything.
 
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
It has to do with purity... I can get sodium carbonate in a lower but perfectly acceptable grade, and the potassium carbonate i can get is pure...
I already checked around ... But no...
 

koraks

Moderator
Moderator
Joined
Nov 29, 2018
Messages
23,294
Location
Europe
Format
Multi Format
You don't need very high purity for this application.
I'm surprised there apparently aren't better retailers of generic chemicals in your country.
 
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
I know that high purity is not an issue and usually i can get cheap chemicals but potassium carbonate is an exception...
 

mshchem

Subscriber
Joined
Nov 26, 2007
Messages
14,748
Location
Iowa City, Iowa USA
Format
Medium Format
1 package (5L) of Ilford Bromophen will make 20 liters of working solution. I've used it for decades. Package the stock solution into full 250ml and 500ml bottles it keeps a long long time.
1 250ml makes liter of working solution.
 
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
mshchem said:
1 package (5L) of Ilford Bromophen will make 20 liters of working solution. I've used it for decades. Package the stock solution into full 250ml and 500ml bottles it keeps a long long time.
1 250ml makes liter of working solution.
Click to expand...
Thanks for your answer but... I have raw chemicals i want to use...
 

Nikola Dulgiarov

Member
Joined
Jul 6, 2008
Messages
181
Location
Europe
Format
Multi Format
ruilourosa said:
Thanks for your answer but... I have raw chemicals i want to use...
Click to expand...
I think that if your end goal is to use the inexpensive chemicals you have available, have a good, known formula, then you can compromise on the concentration Even if a formula requires 2.5x the volume, just use bigger containers.
You can also prepare dry A/B packets to make the concentrate and store them.
 
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
I managed to put 150gr of sodium carbonate into solution but i think adding 5gr of potassium hidroxide helped as the solution only cleared when i added the hidroxide. Its similar to id62.
No cristalization, i will test the developing habilities and characteristics soon as i run out of benzotriazole
 

Ian Grant

Subscriber
Joined
Aug 2, 2004
Messages
23,271
Location
West Midland
Format
Multi Format

What you've actually mixed is not ID-62 rather ID-78 the warm tone variant. I't won't give you fog The Benzotriazole is there to produce Neutral tone in ID-62.

You didn't need to add the Potassium Hydroxide as well as the 150gm Sodium Carbonate you only add Hydroxide if you reduce the Carbonate. to maintain the same pH. The issue is you can get the 150g Sodium Carbonate to dissolve, but depending on temperature it starts to precipitate.

Ian
 
OP
OP

ruilourosa

Member
Joined
Apr 13, 2003
Messages
797
Location
Portugal
Format
Multi Format
I added 5gr of bromide to a liter of concentrate to dilute 1+9, is it enough?
I already ordered some benzotriazole
 

Ian Grant

Subscriber
Joined
Aug 2, 2004
Messages
23,271
Location
West Midland
Format
Multi Format
10g would be better. When Ilford changed their powder developer ID-20 from MQ to PQ in the late 1950's customers complained that the ID-20 PQ was causing shifts in the colour of tones with use. They re-formulated the developer as ID-62 adding Benzotriazole and halved the Bromide, they also increased the concentration and sold it in liquid form as PQ Universal switching from Sodium Carbonate to Potassium Carbonate and Sodium Hydroxide.

Ian
 

koraks

Moderator
Moderator
Joined
Nov 29, 2018
Messages
23,294
Location
Europe
Format
Multi Format
Ian Grant said:
The issue is you can get the 150g Sodium Carbonate to dissolve, but depending on temperature it starts to precipitate.
Click to expand...
Additionally, there can be problems when trying to dissolve the necessary amount of hydroquinone if you already have a lot of sodium carbonate dissolved.
Of course there is no problem in itself dissolving 150g/l sodium carbonate; even anhydrous sodium carbonate has a solubility limit of 164g/l at 15C and OP is likely using either monohydrate (192g/l limit @ 15C) or decahydrate (443g/l @ 15C).

Since we haven't touched on this, @ruilourosa, which species are you using for your developer? Monohydrate or decahydrate? The carbonate you can buy at the supermarket can be either. It's important to determine which you have because of the huge conversion factor between the two; you need more than twice as much decahydrate than monohydrate (2.3 times to be fairly precise).

Finally I second the suggestion of @Nikola Dulgiarov - if you have the components to make a known-good developer that isn't too concentrated, just use bigger bottles and live with it. It's really easy to make a developer that keeps well as a mild concentrate and that mixes 1+2 or 1+3 with water to make a working solution. That, or get some potassium carbonate. Again, I'm fairly sure you can find it for cheap if you search creatively enough. Note that I virtually never buy my chemicals from stores focusing on photography and in fact about half to two-thirds of the stuff I use comes from either the local supermarket or food supply companies.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…