Mixing Pyrocat-HD in Glycol

[sanking]

I get a lot of questions about this and would like to start a thred with a name that can be easily located by search for persons looking for the information. If there are questions, please let me know.

MIXING STOCK SOLUTION A WITH GLYCOL

As many of you know, mixing Stock Solution A of Pyrocat-HD in Propylene Glycol provides stability of the stock solution on the order of years, similar to HC-110. Here is a very safe way to do this, measured for the 1000ml kit.

1. Weigh out all of the chemicals for Stock A. 50.0g of pyrocatechin, 10.0g of sodium metabisulfite, 2.0g of phenidone and 1.0g of potassium bromide.

2. Pre-heat in a water bath or hot plate stirrer 750ml of propylene glycol to about 150F.

3. Add the pyrocatechin to the glycol and stir until dissolved. Should take no more than about a minute.

4. Now add the phenidone and stir. Should dissolve completely in about a minute.

5. Add the bromide and sodium metabisulfite to about 50-75ml of hot water at about 120F. Stir until completely dissolved, then mix with the propylene glycol solution.

6. Top off the solution with glycol to 1000ml.

Once you do this a couple of times you will find it just as easy as mixing Stock A in water. Should you be concerned about the small amount of water in the solution? Absolutely not. Pat Gainer, who is the expert on these type of solutions, has recently recommended this type of mixing for his PC-TEA formula, and if he is satisfied with the stability so am I.

Sandy King

 

[jgjbowen]

Thanks Sandy

 

[gainer]

I shudder at being called an expert on anything. One thing we learned at NASA by diligent research is that a true expert is one who learns more and more about less and less until he knows all there is to know about nothing.

 

[craigclu]

In an industry that I was in, the term "expert" was accepted if you were brought in from more than 100 miles away. Thanks, Sandy for the clear information. I've settled on this as my main, "go-to" developer and especially like the stability for my increasingly sporadic darkroom activities.

 

[pauldc]

Thank you Sandy, really helpful.

Can I also do the same with the Pyrocat-P formula?

 

[Tom Hoskinson]

Thank you Sandy, really helpful.

Can I also do the same with the Pyrocat-P formula?

I'm not Sandy, but yes, you can mix the "A" solutions of both Pyrocat-P and Pyrocat-MC in Propylene Glycol.