Re: More questions - KAuCl2 vs AuCl3 - it's KAuCl4

OK, forget the Au(I) to Au(III) question.
Think to your KAuCl4 like it were AuCl3 + KCl... you have only some extra
KCl.

Alberto

> Ok, it seems that the compound I use is anhydrous KAuCl4... The gold seller
> told me 1.92 gr of this compound has 1 gr pure gold and when you check this
> figure against anhydrous KAuCl4, they match each other. I just finished
> toning an Argyrotype with fresh thiourea-gold toner and it tones to
> completion in about 1 minute (completion is: no further color change and/or
> considerable slowing of color change).
>
> BTW, palladium toning is gone forever for me; the gold toned print is just
> as I want it (in terms of contrast, color and dmax). Palladium toned print
> looks anemic when compared to the gold toned print (thioure-gold that is).
> Will send scans of three prints (untoned, palladium toned & gold toned)
> later, when the prints are dry.
>
> Regards,
> Loris.
>
> -----Original Message-----
> From: Loris Medici [mailto:mail@loris.medici.name]
> Sent: 20 Mayýs 2006 Cumartesi 17:18
> To: alt-photo-process-l@usask.ca
> Subject: RE: More questions - KAuCl2 vs AuCl3
>
> Sorry Alberto, can't provide you any comparison info because I never used
> AuCl3 (impossible to find locally and have to order quite alot - over my
> budget - for having it imported). The formula I provided may not be correct
> since I just learned - from someone posting off-list - that KAuCl2 will
> decompose in contact with water and precipitate gold (something that the
> compound I use doesn't do). The formula is more likely to be something like
> KAuCl4.xH2O. Will pay a visit to Grand Bazaar and learn the exact formula.
>
> Regards,
> Loris.
>
> -----Original Message-----
> From: Alberto Novo [mailto:alt_list@albertonovo.it]
> Sent: 20 Mayýs 2006 Cumartesi 08:53
> To: alt-photo-process-L@usask.ca
> Subject: Re: More questions - KAuCl2 vs AuCl3
>
> Loris,
> did you note anything different between Au(I) and Au(III) toned prints (hue,
> speed, etc.)?
> From a theoretical point of view, though the m.w. is almost the same, the
> substitution of Ag by Au is three times more efficient when using Au(I)
> solutions.
>
> Alberto
>
>
>> A note about gold chloride (AuCl3): one can also use KAuCl2 (which is
>> used in gold plating industry, AFAIK) perfectly for gold toners. For
>> me (a person located in Istanbul) KAuCl2 is cheaper and easier to find
>> (just a short visit to the gold sellers in Grand Bazaar). I use the
>> thiourea-gold formula replacing AuCl3 with KAuCl2. The gold percentage
>> difference is extremely small (AuCl3 -> 64.94% vs KAuCl2 -> 64.16%),
>> therefore you can substitute
>> AuCl3 with KAuCl2 using the exact amounts stated in the formula.
>>
>> Just my 2 cents,
>> Loris.
>
 
Received on 05/20/06-02:31:38 PM Z