RE: cyanotype soln. gone bad

That's a huge amnt. of formaldehyde! I use 15 drops per 1000ml of stock
solution A (I use it only in stock solution A, I don't add it to B).
Still no fungus in 25 months old solution. But I have color running off
in developing water (no big problem - it doesn't stain the highlights
and I have calibrated my exposure/negatives according to this).

Regards,
Loris.

-----Original Message-----
From: Venkatram Iyer [mailto:eyeear@telus.net]
Sent: 06 Eylül 2005 Salı 06:02
To: alt-photo-process-l@sask.usask.ca
Subject: Re: cyanotype soln. gone bad

Joe,Judy,

  I do not know the concentration of the formaldehyde (HCHO) but I get
it from the local pharmacy. 2-3 drops per 12.5 ml of each of A or B
solutions prepared a la James does the trick.

Do let me know if you too find that there is little run of the blue on
development. Rajul

On 5-Sep-05, at 7:18 PM, Joe Smigiel wrote:

> Good tip Rajul but could you please be more specific? Is this 2-3
> drops
> of 37% formalin per liter of stock A and stock B, or is it some other
> concentration and volume?
>
> Thanks for any additional info.
>
> Joe
>
>>>> eyeear@telus.net 09/05/05 12:04 PM >>>
> I add 2-3 drops of formaldehyde to each of the 2 solutions (stored in
> amber colored bottles) used in traditional cyanotype printing and
> store them at 4C in the fridge. This prevents fungus from growing in
> the stock solutions. Prints made using formaldehyde-fortified
> solutions do not run color at development in either plain water or in
> diluted vinegar.
>
> Rajul
>
>
Received on Tue Sep 6 01:37:07 2005