Copper toner chemistry question


Christina Z. Anderson
 

Dear All,

As usual I need a chemist’s input.

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

Chris

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.


Jim Patterson,
 

Hi Chris,
The citrate is the important agent.  It complexes the copper ion to prevent it from precipitating Copper Ferricyanide when A & B are mixed.  Sodium and Potassium are “spectator” ions to keep the compound neutral.  Both salts are very soluble in water.  In some cases the potassium salt of a compound is much less soluble than the sodium salt.  In general they tend to be interchangeable in many formulas, but the same weight of Sodium Citrate has more citrate in it than Potassium Citrate.  The molar mass of PC is higher than SC, so sometimes you have to add more PC to equal the effect of SC in some formulas.

When the Ferricyanide reacts with silver metal, it is reduced to Ferrocyanide and Copper Ferrocyanide is much less soluble than Copper Ferricyanide, and precipitates out, which is the Cuprotype pigment also.

Jim


On Oct 22, 2021, at 7:17 PM, Christina Z. Anderson <christinazanderson@...> wrote:

Dear All,

As usual I need a chemist’s input.

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

Chris

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.


Marek Matusz
 

Chris
The main issue of potassium vs. sodium salts in alt photo is solubility of the different salts. If you want very concentrated solutions typically one has higher solubility vs the other. Resulting solutions will also have slightly different pH probably not relevant in most applications. If the recipe calls for potassium citrate and you use the same weight of sodium citrate you are you sing higher molar concentration of citrate and molecules care about moles not percentages. 
Apparently the recipe for toning is very tolerantto some variations. 
And yes it is very easy to mix own citrates, oxalates etc from acids and sodium or potassium carbonates. Just watch for the bubbling and possibly overflowing the container. Always use large container and add carbonate slowly waiting for the reaction to subside
Marek


On Oct 22, 2021, at 7:17 PM, Christina Z. Anderson <christinazanderson@...> wrote:

 Dear All,

As usual I need a chemist’s input.

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

Chris

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.


Christina Z. Anderson
 

Thanks, Jim! This is exactly what I needed. No egregious chemical error then. I used the same weight as potassium was called for and the color was a deeper copper, more beautiful than the kits I have bought in the past which lean more pinkish copper than reddish.

Chris


On Oct 22, 2021, at 7:09 PM, Jim Patterson, <jimbobnola@...> wrote:

Hi Chris,
The citrate is the important agent.  It complexes the copper ion to prevent it from precipitating Copper Ferricyanide when A & B are mixed.  Sodium and Potassium are “spectator” ions to keep the compound neutral.  Both salts are very soluble in water.  In some cases the potassium salt of a compound is much less soluble than the sodium salt.  In general they tend to be interchangeable in many formulas, but the same weight of Sodium Citrate has more citrate in it than Potassium Citrate.  The molar mass of PC is higher than SC, so sometimes you have to add more PC to equal the effect of SC in some formulas.

When the Ferricyanide reacts with silver metal, it is reduced to Ferrocyanide and Copper Ferrocyanide is much less soluble than Copper Ferricyanide, and precipitates out, which is the Cuprotype pigment also.

Jim


On Oct 22, 2021, at 7:17 PM, Christina Z. Anderson <christinazanderson@...> wrote:

Dear All,

As usual I need a chemist’s input.

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

Chris

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.



Christina Z. Anderson
 

Marek,
I actually have potassium carbonate and citric acid and was going to mix my own but then I thought why the heck not wing it with what was on hand. Ran out of time though, during the lab to do so.
Chris


On Oct 22, 2021, at 7:15 PM, Marek Matusz <marekmatusz@...> wrote:

Chris
The main issue of potassium vs. sodium salts in alt photo is solubility of the different salts. If you want very concentrated solutions typically one has higher solubility vs the other. Resulting solutions will also have slightly different pH probably not relevant in most applications. If the recipe calls for potassium citrate and you use the same weight of sodium citrate you are you sing higher molar concentration of citrate and molecules care about moles not percentages. 
Apparently the recipe for toning is very tolerantto some variations. 
And yes it is very easy to mix own citrates, oxalates etc from acids and sodium or potassium carbonates. Just watch for the bubbling and possibly overflowing the container. Always use large container and add carbonate slowly waiting for the reaction to subside
Marek


On Oct 22, 2021, at 7:17 PM, Christina Z. Anderson <christinazanderson@...> wrote:

 Dear All,

As usual I need a chemist’s input.

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

Chris

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.



BOB KISS
 

DEAR CHRIS,

            A little free advice (by definition, of no value!  LOL!):  Buy a bulk quantity of Potassium carbonate...it is pretty cheap.  As you most likely have citric acid in your lab and you also have oxalic acid, you can then mix, very cheaply, Potassium Citrate for this toner or Potassium Oxalate for developing PT/PD prints and lotza other uses.

                                    CHEERS!

                                                BOB 

 

From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of Christina Z. Anderson
Sent: Friday, October 22, 2021 8:18 PM
To: Alt List
Subject: [altphotolist] Copper toner chemistry question

 

Dear All,

 

As usual I need a chemist’s input.

 

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

 

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

 

Chris

 

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.


BOB KISS
 

OOPSIE!  Looks like you and Jim already covered this.  Email VERY slow this morning and yours didn't download until after I sent mine!

 

From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of BOB KISS via groups.io
Sent: Saturday, October 23, 2021 11:59 AM
To: altphotolist@groups.io
Subject: Re: [altphotolist] Copper toner chemistry question

 

DEAR CHRIS,

            A little free advice (by definition, of no value!  LOL!):  Buy a bulk quantity of Potassium carbonate...it is pretty cheap.  As you most likely have citric acid in your lab and you also have oxalic acid, you can then mix, very cheaply, Potassium Citrate for this toner or Potassium Oxalate for developing PT/PD prints and lotza other uses.

                                    CHEERS!

                                                BOB 

 

From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of Christina Z. Anderson
Sent: Friday, October 22, 2021 8:18 PM
To: Alt List
Subject: [altphotolist] Copper toner chemistry question

 

Dear All,

 

As usual I need a chemist’s input.

 

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

 

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

 

Chris

 

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.


Christina Z. Anderson
 

LOL thanks for the time to respond even if it was already covered!
I’ve been watching your chattel houses on FB. Fun to see.
Chris

On Oct 23, 2021, at 10:05 AM, BOB KISS via groups.io <bobkiss@...> wrote:

OOPSIE!  Looks like you and Jim already covered this.  Email VERY slow this morning and yours didn't download until after I sent mine!
 
From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of BOB KISS via groups.io
Sent: Saturday, October 23, 2021 11:59 AM
To: altphotolist@groups.io
Subject: Re: [altphotolist] Copper toner chemistry question
 
DEAR CHRIS,
            A little free advice (by definition, of no value!  LOL!):  Buy a bulk quantity of Potassium carbonate...it is pretty cheap.  As you most likely have citric acid in your lab and you also have oxalic acid, you can then mix, very cheaply, Potassium Citrate for this toner or Potassium Oxalate for developing PT/PD prints and lotza other uses.
                                    CHEERS!
                                                BOB  
 
From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of Christina Z. Anderson
Sent: Friday, October 22, 2021 8:18 PM
To: Alt List
Subject: [altphotolist] Copper toner chemistry question
 
Dear All,
 
As usual I need a chemist’s input.
 
This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.
 
I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 
 
I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…
 
Chris
 
Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.



BOB KISS
 

Thanks!

 

From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of Christina Z. Anderson
Sent: Saturday, October 23, 2021 12:07 PM
To: Alt List
Subject: Re: [altphotolist] Copper toner chemistry question

 

LOL thanks for the time to respond even if it was already covered!

I’ve been watching your chattel houses on FB. Fun to see.

Chris



On Oct 23, 2021, at 10:05 AM, BOB KISS via groups.io <bobkiss@...> wrote:

 

OOPSIE!  Looks like you and Jim already covered this.  Email VERY slow this morning and yours didn't download until after I sent mine!

 

From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of BOB KISS via groups.io
Sent: Saturday, October 23, 2021 11:59 AM
To: altphotolist@groups.io
Subject: Re: [altphotolist] Copper toner chemistry question

 

DEAR CHRIS,

            A little free advice (by definition, of no value!  LOL!):  Buy a bulk quantity of Potassium carbonate...it is pretty cheap.  As you most likely have citric acid in your lab and you also have oxalic acid, you can then mix, very cheaply, Potassium Citrate for this toner or Potassium Oxalate for developing PT/PD prints and lotza other uses.

                                    CHEERS!

                                                BOB  

 

From: altphotolist@groups.io [mailto:altphotolist@groups.io] On Behalf Of Christina Z. Anderson
Sent: Friday, October 22, 2021 8:18 PM
To: Alt List
Subject: [altphotolist] Copper toner chemistry question

 

Dear All,

 

As usual I need a chemist’s input.

 

This week I had the toning gang lab where I mix up blue toner, thiourea toner, copper toner, selenium, and gold, and the students go to town toning and multiple toning prints.

 

I normally buy a copper toner kit but had not, and unfortunately I forgot to order one chem for mixing my own copper toner, Potassium Citrate. I had lots of Sodium Citrate on hand (use in pt/pd and chrysotype) so I substituted it in the formula below. It worked beautifully. 

 

I don’t think the two citrates are interchangeable. Can anyone explain the difference (aside from, of course, potassium versus sodium) and why the sodium worked well anyway? In the future I’ll just mix my own instead of ordering a kit…unless one of you says it’s an egregious chemistry substitution error…

 

Chris

 

Ferguson’s copper toner

Part A

6 g copper sulfate

24 g potassium citrate

Water to 1000 ml

Add the copper sulfate to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part A. The container does not need to be light tight.

Part B

5 g potassium ferricyanide

24 g potassium citrate

Water to 1000 ml

Add the potassium ferricyanide to the water and stir until dissolved.

Add the potassium citrate to the water and stir until dissolved.

Store in a liter container, marked Part B. The container does not need to be light tight.

At time of use mix equal parts of Part A and Part B and pour into a tray. Once Part A and Part B are mixed together, the combined solution does not keep past one toning session.

Immerse the print in water until evenly soaked.

Drain the print and immerse in the copper toner.

Tone until the color desired is reached, which can be anywhere from a few minutes to really long (30–90 minutes). Some fun stuff can occur with long toning if you desire, such as plating out of copper on the print. However, watch carefully and don’t leave the print unattended or staining can occur.

After toning, rinse the print for 15 minutes in running water and dry.