[pure-silver] Re: Thiourea and Thiourea dioxide
- From: Eric Nelson <emanmb@xxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 23 Feb 2011 12:44:32 -0800 (PST)
It worked ok-ish in that I did get toning eventually; it's very slow, and if
you
bleach too far tone doesn't come back as it does when sepia toning.
It is a totally different process, and I understand that. The color I got was
nice yellow-greenish brown.
What I'd really like to find is a toner (besides tea and coffee) that adds a
cream color to the paper. Presently just working with RC postcard paper so
extended toning and washes aren't a best choice although w/RC I assume longer
washes aren't necessary anyway. I'd just hate to send out a promo and have it
turn brown.. i.e. brown in a bad way!
Eric
________________________________
From: Ray Rogers <earthsoda@xxxxxxxxx>
To: pure-silver@xxxxxxxxxxxxx
Sent: Wed, February 23, 2011 11:50:52 AM
Subject: [pure-silver] Re: Thiourea and Thiourea dioxide
Correct... not all sites show a difference.
I think the FSA or thiourea dioxide toner is more for a special effect. Since
you read about it in Tim's book, did you get the result you were after, even
though it was slow in working?
I suspect you didn't, in which case you might need to spring for it, if that is
really a look you are after....
Ray
--- On Wed, 2/23/11, Eric Nelson <emanmb@xxxxxxxxx> wrote:
>From: Eric Nelson <emanmb@xxxxxxxxx>
>Subject: [pure-silver] Re: Thiourea and Thiourea dioxide
>To: pure-silver@xxxxxxxxxxxxx
>Date: Wednesday, February 23, 2011, 3:57 PM
>
>
>
>I looked it up myself and found these for t. dioxide with the 2 different CAS
>#'s:
>http://www.lookchem.com/cas-418/4189-44-0.html
>http://www.thiourea-dioxide-fas.com/ <--CAS# 1758-73-2
>
>
>This is what I found for my thiourea:
>http://www.jtbaker.com/msds/englishhtml/t3107.htm
>
>
>I won't pretend I know anything about what's on those pages as I'm just
>looking
>for the practical application of the compound with this toner.
>I used my thiourea anyway as I was in a testing mode yesterday and did get
>toning, albeit very slowly, of the prints I had bleached with the
>ferricyanide/pot. bromide combo. That may be my "practical" answer right
>there,
>but since I work w/chemicals w/o getting into molecular structures and
>formulas,
>I'm hoping someone who does might know the answer if it's 'worth' looking into
>getting the t. dioxide or not.
>
>
>Eric
>
>
>
________________________________
From: Ray Rogers <earthsoda@xxxxxxxxx>
>To: pure-silver@xxxxxxxxxxxxx
>Sent: Wed, February 23, 2011 4:45:55 AM
>Subject: [pure-silver] Re: Thiourea and Thiourea dioxide
>
>
>Sources I looked at gave different yet presumably equvilant structures for
>those
>two cas #s
>
>Thiourea is different.
>
>???
>Thiourea sulfoxide?
>
>Did you mean thiourea dioxide rather than sulfoxide?
>(Can you supply the CAS # for that?)
>
>Ray
>
>--- On Wed, 2/23/11, daniel <daniel.bouzard@xxxxxxxxxx> wrote:
>
>
>>From: daniel <daniel.bouzard@xxxxxxxxxx>
>>Subject: [pure-silver] Re: Thiourea and Thiourea dioxide
>>To: pure-silver@xxxxxxxxxxxxx
>>Date: Wednesday, February 23, 2011, 7:01 AM
>>
>>
>>Hello,
>>
>> CAS 4189-44-0 and 1758-73-2 are both for thiourea dioxide under different
>>names. CAS 62-56-6 is for thiourea.
>>Several years ago I tried toning with thiourea sulfoxide following Tim book
>>and
>>it worked very well.
>>
>>Daniel Bouzard
>>
>>
>>Le 22/02/11 23:25, Eric Nelson a écrit :
>>
>>>I'm working from Tim Rudman's toning book and am playing with the FSA toner.
>>>In it he lists thiourea dioxide to be used in the toning bath. Now I have
>>>thiourea that comes from TechChem down in Missouri and called them to see
>>>what
>>>flavor of thiourea I have. Bob called back and he found something odd in
>>>the
>>>CAS listings.
>>>TechChem's thiourea is CAS# 62-56-6
>>>Thiourea dioxide has TWO CAS #'s which he says is "unheard of".
>>>CAS# 4189-44-0 and CAS# 1758-73-2
>>>Since Tim has been known to hang around these parts and others here may be
>>>more
>>>familiar with the CAS catalog system, I'm wondering if these 3 compounds are
>>>interchangeable or what?
>>>
>>>
>>>Thanks
>>>
>>>
>>>Eric
>>>
>>>
>>>
>>>
>>>
>
>
>
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