preparation of ammonium dichromate

[Willie Jan]

Hi,

is it possible to create a bottle of dichromate solution in front, which is stored for a longer period?

Since i only need .1 gram in 100cc of cyanotype, i would like to prepaire more so that the exact grams per solution are closer to the .1 gram.

When i add 1 gram to 100cc and use 10cc water i still have the .1 gram.
My scale goes to .1 gram, but this is a very small amound to measure.....

Willie Jan.

 

[Jim Noel]

Mixing your dichromate in advance as you suggest should be not problem. Just be sur it is well labeled.
I have some more than a year old which I utilized yesterday.
Jim

 

[Willie Jan]

thanks Jim.

 

[Lukas Werth]

Hello Willie Jan,

how are you?

No problem whatsoever with deionized water. I have a small bottle I once received as a contrast agent for Ziatypes (I don't now remember exactly when, but more than 6 years before) which is, for all I can tell, as fresh as ever.

 

[Willie Jan]

Hi Lukas,

i'm fine.
I just received my new chemicals and paper last week for cyanotypes, so i'll be working in the weekends when the weather is bad....

 

[sanking]

Mix the dichromate with *distilled* water and it will last for years. I have on hand some 12-15 bottles of different strength solutions of both ammonium and potassium dichromate mixed with distilled water, most of which were mixed five years or more ago.

Don't contaminate dichromate solutions with tap water. Even small amounts may cause the solution to degrade within a few months.

Sandy King