RE: Lead Toning Cyanotypes - share your experience please

Thanks for the reply Ryuji,

See inline comments below:

-----Original Message-----
From: Ryuji Suzuki [mailto:rs@silvergrain.org]
Sent: 23 Ağustos 2006 Çarşamba 16:51
To: alt-photo-process-l@usask.ca; mail@loris.medici.name
Subject: Re: Lead Toning Cyanotypes - share your experience please

From: Loris Medici <mail@loris.medici.name>
Subject: Lead Toning Cyanotypes - share your experience please
Date: Wed, 23 Aug 2006 15:31:07 +0300

...

RS>"You should be able to dissolve 4-5% at room temperature, but 5% is
about the solubility limit. I can think of two sparingly soluble or only
very slightly soluble lead compounds: lead carbonate and lead halides.
I'd use distilled water, boil and cool before use, if absence of those
cloudy matter is essential. If insoluble matters still form, it's most
likely due to impurities in the chemical stock (especially if it's
technical grade lead acetate)."<

Boiling is to get rid of dissolved gas(es) I presume. Will try that and
mix a weaker 2% solution (I can live with mixing new batches more often
as the toner is used up...)

> 3) I noticed the precipitation while drying the print - the dark tones

> were showing a white veiling which goes off when you rub a paper towel

> to the print. I concluded that it's precipitated
> Lead(II) Acetate and quickly got rid of the print. I touched the dried

> prints with bare hands (but toned using latex gloves) - will I die!?
> ;)

RS>"I would wash it off thoroughly with soap and try to avoid the future
exposure."<

That is exactly what I did. If the new batch mixed as you describe above
still act the same way, I will totally leave the idea of lead toning.

> * In short, how should I use this toner without causing any health
> risk and damage to myself and the viewers/customers/environment?

RS>"I would recommend to avoid lead compounds altogether.

Very small amounts of lead compounds are useful dopants in silver halide
emulsions (a trace amount of impurity that is deliberately added to a
specific part of the crystal to increase light sensitivity) but I don't
like to handle them in my darkroom, even though they are very tiny
amonts, so I had to seek alternative compounds.

The regulation on lead in the US is rather strict. But it should be."<

I understand that. I've read many resource on lead and lead poisoning
last night... BTW, we still use leaded gasoline here in Turkey! :)

Best regards,
Loris.
Received on 08/24/06-05:48:33 AM Z