Re: PYRO part B

Francesco Curcio (msepa.fcurcio@ntt.it)
Sun, 08 Feb 1998 01:40:02 -0800

Richard Knoppow wrote:

> This is the first I've heard that Kodalk is unstable or had bad keeping
>properties. What exactly happens to it?

I translate from the book by Ghedina, O.F. Foto Ricettario [Photo Formulary],
Hoepli Milano 1982 (fifth ed.), p.624:

"Sodium Metaborate Na2B2O4 . 4H2O:...It must be stored in tightly sealed
containers, because in the open air it looses crystallization water
and combines with atmospheric gases [CO2?] changing into Borax
and Sodium carbonate"

I cannot judge if and how much this could really happen.
Though Kodalk (renamed Balanced Alkaly by Kodak) is usually assumed
to be equivalent to Sodium Metaborate, I wouldn't be sure it has
exactly the same formulation.

Francesco Curcio
Milano Italy