Concentrated PQ print developer problems/query

[Sim2]

Hi there,
I have been trying to use a self-mixed print developer (PQ) as a stock solution to be diluted for actual use. Recipe is from Ian Grant @ LostLabours website. It works, but...

Ilford PQ Developer (Concentrated Stock Solution) - Cool Tones
Phenidone 1.25 g
Sodium Sulphite (anh) 125 g
Hydroquinone 30 g 150 g
Potasium Carbonate (anh) 95 g The Sodium Carbonate is best replaced by Potassium Carbonate
Sodium Hydroxide 5.3 g and Sodium Hyrdoxide in the Concentrate which increases solubility.

(Potassium Bromide 5 g )
Benzotiazole 30ml/1% solution
Water to 1L
Dilute 1:9 for use

I have swopped out the soduim carbonate with potassium carbonate and sodium hydroxide, as suggested. All water is distilled water (bottled). I have left out the pot bromide as I was getting a very warm tone with it, replaced by the benzo as listed.

Issues are:
contrast is very low, difficult to get a decent black. Upped dev time to 3min and still not getting the same contrast as a commercial Tetenal developer, had to up the contrast to a grade 4 equivalent (split grade print) from around 2.5 with the Tetenal and still not getting a good solid black. Any thoughts? Any changes to the formula that could achieve this? If I dev to the 1.5-2min recomended times, well blacks were barely black :-(

Could the 3min dev time introduce a slight base level fog? Using Ilford cooltone fibre.

Liking the "finer grain" result with the PQ compared to the Tetenal (for instance) but on the verge of giving up and returning to commercial devs if the results don't shape up pdq!

Any help or thoughts very welcomed.
Sim2.

 

[Mike Crawford]

Why not use Ilford PQ developer? I can appreciate the benefits of mixing some more esoteric developers from formulae, (and I do), but have never seen any cost benefit compared to the inconvenience of mixing from stock if available commercially by the bottle.

 

[Sim2]

Why not use Ilford PQ developer? I can appreciate the benefits of mixing some more esoteric developers from formulae, (and I do), but have never seen any cost benefit compared to the inconvenience of mixing from stock if available commercially by the bottle.

This is a very fair point and one that is very much at the forefront of my current thinking, cost benefit comparisons were not at the top of my agenda, intrigue with the process and "trying something new" was probably the driving force - returning to commercial devs is very much still on the cards!

 

[Gerald C Koch]

The following lines appear to be a bit jumbled can you clarify them. Why are there two weighs for hydroquinone? Can you correct the lformula so that it reads like a proper formula.

Hydroquinone 30 g 150 g
Potasium Carbonate (anh) 95 g The Sodium Carbonate is best replaced by Potassium Carbonate
Sodium Hydroxide 5.3 g and Sodium Hyrdoxide in the Concentrate which increases solubility.

 

[Sim2]

*unable to edit original posting*

Amended the text from original post:

Ilford PQ Developer (Concentrated Stock Solution) - Cool Tones
Phenidone 1.25 g
Sodium Sulphite (anh) 125 g
Hydroquinone 30 g
Potasium Carbonate (anh) 95 g
Sodium Hydroxide 5.3 g

(original source has: Potassium Bromide 5 g which I have ommitted)
Added to recipe: Benzotiazole 30ml/1% solution

(original source uses sodium carbonate and has these instructions: "The Sodium Carbonate is best replaced by Potassium Carbonate and Sodium Hyrdoxide in the Concentrate which increases solubility.")

Water to 1L
Dilute 1:9 for use

Hope this makes sense to people and may assist any answers!
Thanks.

 

[Gerald C Koch]

Much clearer. One more question. How long are you developing your prints (time and temperature)? Poor blacks are sometimes the result of pulling a print before it has completely developed.

 

[pdeeh]

The trouble with taking a formula and making substitutions is that you have a new formula afterwards

Ian gives two formulae, one for a "normal" stock and one for a "concentrated" stock (for greater keeping quality)

Which is this?

I've made PQ a few times from the formula on Ian's site, and found no problems with blacks.

Apart from ensuring that you substituted the correct amount of potassium Carbonate for sodium Carbonate, I'd check that you've got your benzotriazole concentration correct.

The only time I've ever ended up with truly weak blacks is when I've added far too much benzotriazole to a developer (when trying to control fog in ancient papers)

 

[Sim2]

As stated in the title; "concentrated".

The trouble with taking a formula and making substitutions is that you have a new formula afterwards

Ian gives two formulae, one for a "normal" stock and one for a "concentrated" stock (for greater keeping quality)

Which is this?

I've made PQ a few times from the formula on Ian's site, and found no problems with blacks.

Apart from ensuring that you substituted the correct amount of potassium Carbonate for sodium Carbonate, I'd check that you've got your benzotriazole concentration correct.

The only time I've ever ended up with truly weak blacks is when I've added far too much benzotriazole to a developer (when trying to control fog in ancient papers)

 

[Sim2]

Gerald,

Hallo, deve'd for 2.5 to 3 mins on a dish warmer @ 20C.

Much clearer. One more question. How long are you developing your prints (time and temperature)? Poor blacks are sometimes the result of pulling a print before it has completely developed.