Is There A Correct Formula For Defender D55

[dancqu]

Dupont Defender D 55 or D55 or 55D or 55 D, however you spell it
I've seen two formulas for it. Is there A correct formula. Dan

[Jon King]

Dupont Defender D 55 or D55 or 55D or 55 D, however you spell it
I've seen two formulas for it. Is there A correct formula. Dan

From Photo Lab Index:


Water, 125 F/52C 500cc
Metol 2.5g
Sodium Sulfite, desiccated 37.5g
Hydroquinone 10.0g
Sodium Carbonate, monohydrated 44.0g
Potassium Bromide 5.0g
Cold Water to 1.0 l

I don't know what the two formulas are, but this one is straight from its source.


Jon

[MikeK]

My Souce, old text from about the late 1940's-50's is a little different:

water 750ml
Metol 2.5 grams
Sodium Sulfite 37.5 grams
Hydroquinone 10.0 grams
Sodium Carbonate 37.5 grams
Potassium Bromide 13.0 grams

Me thinks I will do some more research.....But both formula should give good results

Mike

[Tom Hoskinson]

My Souce, old text from about the late 1940's-50's is a little different:

water 750ml
Metol 2.5 grams
Sodium Sulfite 37.5 grams
Hydroquinone 10.0 grams
Sodium Carbonate 37.5 grams
Potassium Bromide 13.0 grams

Me thinks I will do some more research.....But both formula should give good results

Mike

The difference in Sodium Carbonate weights between the 2 recipes is 17% this is consistent with the 37.5 grams being the anhydrous form and the 44 grams being the monohydrated form of Na CO3. If so, the two recipes are functionally the same.

[Ian Grant]

Checking in my Focal Encyclopedia of Photography, 1958 edition, both these are probably correct:

Metol 2.5 grams
Sodium Sulfite (anhyd) 37.5 grams
Hydroquinone 10.0 grams
Sodium Carbonate (anhyd) 37.5 grams (44.0 gms is for the Monohydrate form)
Potassium Bromide 4.8 - 12 grams
Water to 1 litre

The formula is actual shown in a comparison chart at about 1/3 this strenght and weights are rounded up or down slightly. But it is suggested that the Bromide is variable depending on the warmth required.

[martin@jangowski.de]

The difference in Sodium Carbonate weights between the 2 recipes is 17% this is consistent with the 37.5 grams being the anhydrous form and the 44 grams being the monohydrated form of Na CO3. If so, the two recipes are functionally the same.

The main difference is the bromide quantity, and this is what makes this developer more or less warm. I tried the version with 13g bromide and found it an excellent and very warm tone developer for the Forte Polywarmtone paper.

Martin

[dancqu]

The main difference is the bromide quantity, and this is what makes this developer more or less warm. I tried the version with 13g bromide and found it an excellent and very warm tone developer for the Forte Polywarmtone paper.
Martin

Apart from the bromide which can vary, 55D differs from D72
only in it's agent and sulfite ratios to carbonate.
For metol the ratios are 1:18 in 55D,and 1:27 in D72.
The sulfite to carbonate ratios are in order, 15:18 and 15:27. If 55D's
carbonate were uped to 67 grams mono it would be D72.

You've probably guessed, I think the ratio method a good way to analyze
a formula.

BTW, the 'other' 55D formula was not even close. Having only metol
it was very nearly the formula for FX-1 film developer which I've found
makes a very nice PRINT developer. I thought I'd found a print developer
equivalent of the film developer FX-1. Dan

[MSchuler]

I was comparing the Defender D55 recipe in the Chemistry Recipes section to the formula in the Darkroom Cookbook and noted that, most significantly, the APUG formula does not contain any hydroquinone. I would think that this omission would greatly affect the appearance of prints. Has anyone used these two formulas and can you describe how they differ in effect?

Also, If I mix the hydroquinone-free formula, would it be a problem to add it back in afterwards? I'm thinking that this might be a good way to test the developer's effect, but am worried about problems disolving, etc. due to out-of-order mixing.

Thanks in advance

[Bruce Osgood]

Mixing Order To make1 Liter
Distilled Water @52-c 750 mL
1 METOL 2.50 g
2 SODIUM SULFITE - ANHY 37.50 g
3 HYDROQUIONE 10.00 g
4 SODIUM CARBONATE - ANHY(1) 37.50 g
5 POTASSIUM BROMIDE* 13.50 g

(1) Mono = Anhy * 1.17 (44g) g
Cold/Cool Distilled Water: 250 mL
Dilute 1 + 1, 2 or 3 (1+3 Recommended). *Amount Bromide can vary from 4 to 20 g: More bromide = warmer tones. To increase contrast add some(?) Sodium Hydroxide

[Tom Hoskinson]

Also, If I mix the hydroquinone-free formula, would it be a problem to add it back in afterwards?

There should be no problem with adding the hydroquinone later.

However, there very likely would be a problem adding the metol later. Metol does not like to dissolve in a strong solution of sodium sulfite.

Many formulations that contain metol advise dissolving just a "pinch" of sodium sulfite first, then dissolving the metol, followed by the other chemicals.

By the way, I would expect the metol only version to be very slow working and "soft."