Proper storage for Pyrocat HD components?

[IanBarber]

I was recently sent some Pyrocat HD

Now rather than sending it pre-mixed or in separate bags, all the A ingredient was in a bag and all the B ingredient in another bag.

Question:

Because all the powder ingredient is mixed together in one bag for each part, will I need to mix them now or will they be ok left as they are until I am ready to use it.
I wasn't sure if the chemicals would deteriorate faster together in dry powder.

[Michael R]

It is difficult to say for sure because this will depend on the quality of the individual compounds and most importantly how they were handled/stored before they got to you. How much air and/or moisture is in the bags etc. If the B bag is just carbonate it should be ok for a while. Storing the part A compounds in one combined dry mix is not ideal.

Remember to be careful when mixing dry catechol.

[IanBarber]

It is difficult to say for sure because this will depend on the quality of the individual compounds and most importantly how they were handled/stored before they got to you. How much air and/or moisture is in the bags etc. If the B bag is just carbonate it should be ok for a while. Storing the part A compounds in one combined dry mix is not ideal.

Remember to be careful when mixing dry catechol.

Thanks for the reply, I guess its a gamble as to whether its going to deteriorate faster in the bag or if I mix it in water and leave it as a solution in the cupboard

[Jim Noel]

MIx itin glycol and you shouldn't have to worry about deuteriation. I mix mine from raw chemicals and have never had it go bad.

[Ari]

I receive Pyro from Bostick & Sullivan, two 500mL bottles.
Bottle A is dry, the instructions say to mix with water only when needed.
Bottle B is already mixed. Shelf life is about a year this way.

[IanBarber]

MIx itin glycol and you shouldn't have to worry about deuteriation. I mix mine from raw chemicals and have never had it go bad.

Ah.. Yes, Glycol might be the solution here, thanks

[esearing]

Mix now and remove all air so the phenidone is preserved and store in a dark interior cabinet until ready for use, put it in two or more containers if you are an infrequent/low volume shooter. Once you open it again you have 6 months to 1 year before it goes bad unless you can evacuate the air every time from the storage container.
I have had HD in glycol go bad just as quickly as distilled water while other people claim it lasts for years. I quit using it due to too many failures and switched to Pyrocat M and make a fresh small batch yearly. You can sometimes tell if it is going bad by comparing negatives that were developed when fresh vs aged developer by comparing the color of the negatives. If the margins are pink-ish rather than the same tan, your developer will fail soon. When Metol fails it turns the solution blue as soon as you add part B.