Edwal Liquid Orthazite

[Adrian Twiss]

I intend to make up some Agfa 108 high contrast developer which calls for 30ml of Edwal Liquid Orthazite. Edwal Liquid Orthazite is described as a 3% solution of benzotriazole with "some sodium sulphite" (The Darkroom Cookbook - Stephen Anchell). Is there anyone out there who knows or could make an educated guess at how much sodium sulphite is required?

I could substitute the Orthazite with 2 grams of potassium bromide but I want to avoid the resultant green cast.

Any help would be much appreciated.

Happy New Year to you all.

 

[Tom Hoskinson]

I intend to make up some Agfa 108 high contrast developer which calls for 30ml of Edwal Liquid Orthazite. Edwal Liquid Orthazite is described as a 3% solution of benzotriazole with "some sodium sulphite" (The Darkroom Cookbook - Stephen Anchell). Is there anyone out there who knows or could make an educated guess at how much sodium sulphite is required?

I could substitute the Orthazite with 2 grams of potassium bromide but I want to avoid the resultant green cast.

Any help would be much appreciated.

Happy New Year to you all.

I keep a 1% stock solution of Benzotriazole dissoved in alcohol (1gm Benzotriazole dissolved in 100ml of either Isopropyl, Ethyl or Methyl alcohol) - this stock solution has a very long shelf life. I typically add about 10ml of this solution per liter of working paper developer to reduce fog and produce blue/black image tones.

Ron Mowrey has advised that aqueous alkaline solutions of Benzotriazole can slowly decompose - adding sodium sulfite increases the solution pH and exacerbates the decomposition problem. Ron recommends the use of alcohol as the only solvent for the 1% Benzotriazole stock solution. - no water and no sodium sulfite. A bonus is that Benzotriazole is very soluble in alcohol - and it is less soluble in water.

 

[Gerald Koch]

According to the MSDS Orthozite is a 2.7% solution of benzotriazole. The amount of sodium sulfite is said to be <5%. Using 5% isn't going to hurt anything.

 

[Adrian Twiss]

Gerald

Thanks for this helpful piece of information. I will try 5%