Propylene Glycol as base for everything

[Bruce Osgood]

I am coming to the impression that Propylene Glycol can be used as the base substance in place of distilled water in most recipes. Is this true?

Specifically, I've always had problems mixing a little (7.5g) Potassium Carbonate Anhy with 10mL distilled water to make a net usable 5mL for a 250 mL solution of Pyrocat HD and tossing the remaining 5mL. To mix a larger amount of Part B has always been a waste of chemistry because it does not store well.

Could not this Part B be made using PG, maybe 100mL PG with 75g Pot.Carb. and saved in an air tight container and 5mL drawn off as needed?

 

[JLP]

I am not aware that the there should be any storage problems with part B mixed in distilled water. I mix 1 liter at a time and it last me close to a year without any problems. Part A i do mix in PG (Pyrocat MC)


jan

 

[Bruce Osgood]

I am not aware that the there should be any storage problems with part B mixed in distilled water. I mix 1 liter at a time and it last me close to a year without any problems. Part A i do mix in PG (Pyrocat MC)


jan

I can't believe that :confused: . I've never been able to keep Part B overnight.

I've mixed 100 mL and used what was needed for the first set of negs that were just fine and the second set went blank on me, not an hour later. I've had a lot of problems with P-Cat HD that others do not seem to have but thought I traced it back to my Part B solutions.

 

[juan]

For carbonate, I simply mix the appropriate amount directly into the working strength developer. Remember that grams and ml count the same. Figure out how much carbonate is in your working strength developer. If it's 5ml, then simply put 5g of dry carbonate into the mix water. There's no need to make a B solution.
juan

 

[sanking]

I can't believe that :confused: . I've never been able to keep Part B overnight.

I've mixed 100 mL and used what was needed for the first set of negs that were just fine and the second set went blank on me, not an hour later. I've had a lot of problems with P-Cat HD that others do not seem to have but thought I traced it back to my Part B solutions.

Something is very wrong here with your mixing or storage. Carbonate solutions mixed in water should last for years. Specifically, the Pyrocat-HD B solution, which is a 75% carbonate solution, should have a shelf life of at least three years if mixed in distilled water.

Sandy King

 

[Photo Engineer]

I second what Sandy has said. I would keep it in a closed container, but otherwise carbonate in water is very very stable.

PE

 

[gainer]

I have some that is about 3 yrs old that still works fine. However, the carbonate is easily and quickly soluble in the working solution. Furthermore, you can substitute sodium carbonate in the ratio of the molecular weights if you do it that way. 6.5 grams anh. sodium carbonate is worth 7.5 grams anh potassium carbonate. That gives you the same number of carbonate ions.

Besides, the carbonate will not dissolve to any usable extent in glycols.

If you are talking about mixing yesterday's part B with yesterday's diluted part A, forget it. That's where the problem would be, not in the carbonate.

 

[Jordan]

Inorganic salts like potassium carbonate, sodium sulfite, borax, etc. will not dissolve in propylene glycol to a level that would be useful for mixing stock solutions.