ABC Pyro & DBI

[Alan9940]

Hello All,

Thinking about trying my hand at DBI using ABC Pyro and I have a few questions:

1. MAS formula, as published on michaelandpaula.com, calls for a 10% solution of Potassium Bromide. I have some Kbr 10% that I mixed up using distilled water for a project last winter. It has sat on the shelf in my darkroom--I live in the desert southwest USA so my home gets fairly warm during the summer months--since that time. Does this solution go bad?

2. I found another Solution A reference that calls for 1.1g Kbr in total volume of 1 liter. Since I have the dry chemical on hand I could use it. Not to ask the dumb question, but we are looking at weight vs volume...is this equivalent to a 10% solution. Or, I could go with what I already have mixed, if still good.

3. I've read on the Azo Forum that the stain can vary based on the age of the Sodium Sulfite in Solution B. Anyone actually experience this? Age-wise what are we talking, months? years? decades?

4. Every reference I've seen for Solution C calls for Sodium Carbonate, Monohydrate at 80g. I have Anhydrous on hand and I know that the difference between the two is that Mono contains one molecule water whereas the Anhydrous doesn't contain any water, theoretically. Of course, we all know that Anhydrous forms of chemical absorb water from the air over time. Since I already have the Anhydrous, what amount should I use? Or, just not worry about it and use 80g?

5. Anybody have a starting time to begin inspection for HP5+?

Sorry, more than a few questions! Thanks for any help provided.

Best regards,
AlanH

 

[Mustafa Umut Sarac]

Potassium Bromide and Sodium Sulfite mix with water storage life

Hello All,

Thinking about trying my hand at DBI using ABC Pyro and I have a few questions:

1. MAS formula, as published on michaelandpaula.com, calls for a 10% solution of Potassium Bromide. I have some Kbr 10% that I mixed up using distilled water for a project last winter. It has sat on the shelf in my darkroom--I live in the desert southwest USA so my home gets fairly warm during the summer months--since that time. Does this solution go bad?

2. I found another Solution A reference that calls for 1.1g Kbr in total volume of 1 liter. Since I have the dry chemical on hand I could use it. Not to ask the dumb question, but we are looking at weight vs volume...is this equivalent to a 10% solution. Or, I could go with what I already have mixed, if still good.

3. I've read on the Azo Forum that the stain can vary based on the age of the Sodium Sulfite in Solution B. Anyone actually experience this? Age-wise what are we talking, months? years? decades?

Alan,

I looked to sigma site and it says kbr solutions have limited life. I think hot weather and 1 year is enough to go bad. I think same as sodium sulfite.

Potassium bromide solution
shelf life limited shelf life, expiry date on the label

umut

 

[Gerald C Koch]

Sodium carbonate will absorb moisture from the air if not stored properly. Under such conditions it will be converted to the monohydrate. You can bring it back to the anhydrous state by heating in a 350F over for 1 hour. Use a glass or stainless steel pan. Stir a couple of times during the heating. Allow it to cool and then store in a well sealed jar. I use canning jars for this purpose. They are cheap and easily available. BYW it is impossible to "over cook" the sodium carbonate.

Pyrogallol is very poisonous. It's use should not be taken lightly. The minimum lethal dose LDlo is 28 mg per kilogram of body weight. For a 160 lb man that is only 2 grams. Use a dusk mask and gloves when handling the solid and gloves for any solutions. Damage to the body is cumulative so multiple exposure does have its effect. This chemical really has no place in one's home. Catechol based staining developers are safer.

 

[Alan9940]

Thank you all for the valuable info so far.

All the dry chemicals that I currently have on-hand were purchased from the Photo Formulary. The Sodium Sulfite has been stored in the plastic container as delivered by PF and kept in a cool, dry place. I have read that Solution B has possibly been the cause of staining developer inconsistencies so I plan to mix that fresh, as needed.

Gerald - my Sodium Carbonate has been stored in the plastic containers from the Formulary and kept in a cool/dry place. One has been opened and used for other projects; the other still has the seal around the lid. Do you think either or both have morphed into a monohydrate or can I assume they're still closer to anhydrous? I guess I could just "cook" both to be sure. Going forward I will store it in canning jars. I've done this with a couple of other chemicals...don't know why I didn't think of it for all.

Best regards,
AlanH

 

[Gerald C Koch]

Your sodium carbonate is probably OK.