Re: Help with what I believe is a hardening issue

Thanks Tom, I appreciate your answer. Originally the use for the
formalin was in printing of Agfa color prints. I used it in the
stabilizer to harden the emulsion and "lock" in the color so to speak.
Haven't used for a thing since then.
Jack

On Nov 22, 2004, at 7:44 AM, T. E. Andersen wrote:

Hi Jack!

That's all very well, as long as you can accept the uncertainties. The
"white substance" is a polymer of the formaldehyde, and means you no
longer have a 37% solution. Also, formalin this old will have very
significant amounts of formic acid, also formed from formaldehyde,
through oxidation and disprop., further reducing the actual
formaldehyde concentration. This may or may not interfere with what you
are doing, you will have to be the judge of that. If you choose to use
formalin this old, you need to pay very close attention when you
finally purchase new stock. It will be quite different from the last
drops of your old bottle...

Best regards,

Tom Einar Andersen

Jack Fulton wrote:
> I've had, since the late 1960's, a gallon of Formalin (37%
> formaldehyde) which is the primary form used in photography. It comes
> from a local Bay Area laboratory. There are a few small flakes of a
> white substance on the bottom of the heavy duty plastic jug and other
> than that there seems to be zero deterioration.
> Jack Fulton
Received on Mon Nov 22 10:57:11 2004