Re: Help with what I believe is a hardening issue

From: Tom Ferguson ^lt;>
Date: 11/22/04-10:33:37 AM Z
Message-id: <>

Not that many years ago (before I switched to Glyoxal) I could buy this
in ?quart? sized bottles as a walk in customer at Tri-Ess in Burbank.
I'm confused, is it now impossible to buy?

On Monday, November 22, 2004, at 07:44 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
Tom Ferguson
Received on Mon Nov 22 10:33:53 2004

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