Re: question about making platinum salt


rocky (rocky@pdq.net)
Mon, 19 Jul 1999 08:43:57 -0500


Bravo!
Price isn't everything.
Quality, service and delivery count.
Like I was taught, you can have quality, service, delivery or price. Pick 3.

Great meeting at APIS.

Thanks B&S!

Rocky

At 09:30 PM 7/18/99 -0600, Richard S. Sullivan wrote:
>At 05:13 PM 7/18/99 -0400, you wrote:
>>Lukas Werth wrote:
>>> ...
>>> I have an opportunity to get here in Germany for a decent price
>>> chloroplatinic acid, H2PtCl6.6H20. Is it possible - and feasible - to
>>> produce the platinum salt needed for prints, K2PtCl4 ...
>>
>Jeff Mathias replies:
>
>>I believe that you will find that the production of K2PtCl4 will also
>>involve the use of aqua regia. Hopefully you've read the previous
>>discussions involving gold chloride.
>
>Dick replies in situ:
>
>Not true in his case. He already has the chloroplatinic acid which is post
>aqua regia so that is not an issue.
>>
>>The two cents I would like to throw in is that while K2PtCl4 is the
>>double salt of platinum that is desired, it is very easy to also get
>>K2PtCl6 along with its production.
>
>Half true. It is the avenue through which K2PtCl4 is made in the most
>common synthesis process. The K2PtCl6 is reduced to K2PtCl4. It is the
>incomplete reduction that leaves some of the K2PtCl6.
>
>>This later salt is not very soluble.
>
>True
>
>>in water and ends up as a precipitant which may cause problems such as
>>specks in the print.
>
>Not true in my experience. This is cited in some early texts but I have
>added small quantities and coated it in with the emulsion with no visible
>effect. I often use reclaimed sludge from the lab that Dana is scheduled to
>recycle by reducing back to metal. This is dregs of various stuff from
>beakers etc. It's loaded with 'Cl6, Pt black and other secondary products.
>I am careful to not suck up any goop from the bottom and it makes perfectly
>good prints. I give Dana back the sludge for reclamation.
>
>This seems to be like the urban legend that iron causes problems. Phil
>Davis once coated a print with a rusty nail with no ill effects. Sam Wang
>also debunked this theory as well.
>
>>At the least it will render some of the expensive
>>platinum unusable by tying it up in this insoluble sludge.
>
>True.
>
>>Companies
>>like Engelhard go to great expense to produce a pure product.
>
>That we do.
>
>> And
>>although I have no doubt that K2PtCl4 can be produced by others, I have
>>not to this day found a cheaper, purer, easier to obtain source of
>>K2PtCl4 (or PdCl2) than Engelhard.
>
>Not true. Call B+S for a quote.
>
>Easier? Try ordering online from Englehard with a credit card. Pay
>Englehard with a check and you'll wait for it to clear although they seem
>to be on-again off-again about checks at all.
>
>While you're at it, you might also try asking Englehard to help you solve
>some problems you are having with your prints. You might also ask them
>what they have contributed to the alt-photo community. Frankly they could
>give a damn.
>
>>
>>I don't work for them. And, I don't get any commission.
>
>I work for B+S and do get a "commission."
>
>
>Cheers.
>
>--Dick Sullivan
>
>
>



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