Is `DK-76d` a feasible formula?

[Keith Tapscott.]

I haven`t made any yet, but is a formula which might be described as DK-76d a feasible formula? I have considered making this as a developer which perhaps has an activity approximately intermediate of the standard D-76/ID-11 and standard DK-76 formula's but with good pH stability and a decent shelf life when mixed as follows.

Sequestering agent (?) = ?
Metol (Elon) = 2 grams
Sodium Sulphite = 100 grams
Hydroquinone = 5 grams
Sodium Metaborate (Kodalk) = 8 grams
Boric Acid = 8 grams
WTM 1 litre of stock solution.

Any advice welcome.

 

[Ian Grant]

Both Fuji and Konica produced buffered variants of D76, but you should use Borax rather than Boric acid, the buffer combinations are Borax/Boric acid or Borax/Sodium Metaborate

KD28

Metol 2g
Sodium Sulphite 100g
Hydroquinone 5g
Borax 8g
Boric Acid 8g
Potassium Bromide 0.4g
Water to 1 litre

KD22

Metol 1.5g
Sodium Sulphite 100g
Hydroquinone 3g
Borax 0.5g
Sodium Metaborate 3g
Water to 1 litre

Ian

 

[Keith Tapscott.]

Both Fuji and Konica produced buffered variants of D76, but you should use Borax rather than Boric acid, the buffer combinations are Borax/Boric acid or Borax/Sodium Metaborate

KD28

Metol 2g
Sodium Sulphite 100g
Hydroquinone 5g
Borax 8g
Boric Acid 8g
Potassium Bromide 0.4g
Water to 1 litre

KD22

Metol 1.5g
Sodium Sulphite 100g
Hydroquinone 3g
Borax 0.5g
Sodium Metaborate 3g
Water to 1 litre

Ian

Boric acid `is` in the first formula which is simply the D-76d buffered-borax formula with the addition of potassium bromide. The second is a weak D-76 with both Borax and Kodalk for which I guess that the Kodalk makes the developer slightly more active than with Borax alone.
Why shouldn`t I use include Boric acid in my formula with Kodalk?:confused:

 

[Keith Tapscott.]

The KD22 looks interesting and should have greater buffering than the standard D-76/ID-11 formula. How do the processing times compare? I assume that the Borax is dissolved first to provide slightly lower pH than with Kodalk alone.

 

[Ian Grant]

To produce the buffer you need Borax, boric acid/metaborate won't work.

Ian

 

[Keith Tapscott.]

So Borax + Boric acid produces greater buffering than Borax alone, but Kodalk + Boric acid doesn`t work. I am confused by this as Borax and Kodalk are both Borates.

 

[psvensson]

Boric acid and metaborate will form a buffer. In fact, boric acid plus any alkali can form a borate buffer, because the alkali converts some of the acid to the alkali. I use a metol-ascorbic-acid mixture that has TEA and sulfite as alkalis, tempered by boric acid.