[alt-photo] Re: dilution of pt/pd

[Clay Harmon Website]

I think the purpose of the water 'extender' is to ensure that you can get a large coated area completely covered in a smooth way before the solution begins to sink into the paper and become difficult to even out.  Like I mentioned earlier, once the coating on the paper is dry, it really doesn't matter what the original dilution was - the only thing that matters for a good print is that you have sufficient FO and Pd/Pt per square inch to give you the deep black tones you want. 

Percentage, molar, bicuspid or incisor - whatever.

Clay
On Jul 22, 2010, at 12:36 PM, Paul Viapiano wrote:

> All I can tell you is I've done it and it works...it's just a very basic general guideline.
> 
> I haven't talked to Stan about this issue personally, and don't know if he's changed anything since the book. Of course, the usual caveats for different paper, humidity, etc all apply.
> 
> Some people have reported solarization as Clay has...but my guess is that you can add a bit of water to the coating solution as long as you don't overdo it to get it to brush on a bit smoother.
> 
> 
> 
> 
> ----- Original Message ----- From: "Christina Anderson" <zphoto at montana.net>
> To: "The alternative photographic processes mailing list" <alt-photo-process-list at lists.altphotolist.org>
> Sent: Thursday, July 22, 2010 9:15 AM
> Subject: [alt-photo] Re: dilution of pt/pd
> 
> 
>> Hmmm...I'm not sure what I am misunderstanding--50% of 12ml would only be 6ml, and he is adding 7.5. Am I reading you wrong?
>> 
>> OH, I think we're talking apples to oranges, because I mean 50% of the original volume, not 50% of the final volume.
>> 
>> Interesting that he is adding 50% of the initial volume in water to 3ml, less than 50% to 8, more than 50% to 12. I wonder what he has found to make that variance. Ratio of water to total final volume being from 30-38% which I suppose is not that big of a deal--maybe. I mean, a variance of 8%.
>> 
>> Chris
>> 
>> Christina Z. Anderson
>> christinaZanderson.com
>> 
>> On Jul 22, 2010, at 10:48 AM, Paul Viapiano wrote:
>> 
>>> No, Christina...I said starting at 12ml.
>>> 
>>> He adds 1.5ml to 3ml to get 4.5ml, adds 3.5ml to 8ml to get 11.5ml, adds 7.5ml to 12ml to get 19.5 ml
>>> 
>>> That's what his chart in the book indicates..he also said these are guidelines to check out, if I recall.
>>> 
>>> p
>>> 
>>> 
>>> ----- Original Message ----- From: "Christina Anderson" <zphoto at montana.net>
>>> To: "The alternative photographic processes mailing list" <alt-photo-process-list at lists.altphotolist.org>
>>> Sent: Thursday, July 22, 2010 6:35 AM
>>> Subject: [alt-photo] Re: dilution of pt/pd
>>> 
>>> 
>>>> This is interesting, Paul. Thanks.
>>>> 
>>>> Wow, when he gets up to 12ml he's adding over 50%?? Does he say he is double coating then?
>>>> Chris
>>>> 
>>>> Christina Z. Anderson
>>>> christinaZanderson.com
>>>> 
>>>> On Jul 21, 2010, at 4:53 PM, Paul Viapiano wrote:
>>>> 
>>>>> In the appendix of the Arentz book, Stan Klimek says that he extends the platinum solution by adding distilled water.
>>>>> 
>>>>> It's my understanding that he doesn't extend the solution if he's using less than 3ml of total solution (FO + pt). But starting at 3ml he extends by adding 1.5ml distilled H20, 8ml by adding 3.5ml, 12ml by adding 7.5 ml.
>>>>> 
>>>>> He states that this wetter solution makes for a smoother coat.
>>>>> 
>>>>> I believe he also states that his pt/pd ratio is 1:5.
>>>>> 
>>>>> Paul
>>>>> 
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