ID-78 paper developer color

[archer]

I mixed a warmtone developer tonight and it turned the color of coffee. This developer is said to be similar to Ilford ID-78. Here is the formula:
water=1000ml
phenidone=0.5g
hydroquinone=12g
sodium carbonate=62g
potassium bromide=4.5g
My question is... after adding the hydroquinone, the developer started to darken and after completely mixed, it resembles coffee. Is this normal with this formula? Distilled water was used in mixing and all the chemicals were fresh or nearly so with the exception of the phenidone which was a very light cream color not quite tan.
Denise Libby

 

[Doremus Scudder]

Denise,

It looks like the sodium sulfite is missing from your formula. It acts as a preservative for the developing agents keeping them from oxidizing quickly. When they oxidize, they turn brown. Maybe you overlooked the ingredient or...?

Best,

Doremus Scudder
www.DoremusScudder.com

 

[RalphLambrecht]

Denise

I believe Doremus already spotted the error. The ID-78 formula, I have from Ian Grant, lists 50 g of sodium sulfite to be added to the water first. As he states, sodium sulfite is a common preservative for developers, and is designed to prevent oxidation.

Some minor points, I would start with 750 ml of water, add the chemicals in sequence of the recipe, and then fill it with water to make 1l, otherwise, you end up with more than 1l, and that's not what the intent of the recipe is. Also, my recipe lists 72 g of sodium carbonate (monohydrate). Sodium carbonate acts as a buffer to stabilize the pH value. Your recipe may ask for sodium carbonate (anhydrous), which would explain the difference. Just make sure to modify the formula to match the type of sodium carbonate used.

 

[archer]

I feel like such an idiot. I've been mixing chemicals for decades and this is the first time I misread a formula. Thanks for catching the blunder guys. TOO SOON OLD--TO LATE SMART.
Denise Libby

 

[Mick Fagan]

Ralph, my Ilford manual of photography book, does list 62g sodium carbonate (anhydrous) in the ID-78 formula.

I actually use this formula 1 part stock with 3 parts water, makes the stock solution go further and development time is 2 minutes according to Ilford; I use 2.30" to ensure full development and consistency.

Mick.

 

[RalphLambrecht]

Ralph, my Ilford manual of photography book, does list 62g sodium carbonate (anhydrous) in the ID-78 formula...

That makes sense, 62 g (anhydrous) and 72 g (monohydrate) are equivalent. I prefer the monohydrate as it is more stable. Given time, anhydrous will be monohydrate anyway.