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

[Terry King]

Well the discussion would certainly seem to confirm that  all this chat about molarity is very pointy hat. 


There are other strange happenings. 


Who is using gramme scales to measure noble metal salts, or can you measure tenths on them? Accurate scales measuring down to a tenth of a gramme and less are not expensive and are easily available. 


Who is using kits ? Why not get the salts straight from chemical suppliers ?


Who is using molar calculations with cyanotypes, the cheapest and simplest of processes ?








'Molarity' has it's place but somebody is going to have to demonstrate that you can get a better print for less money with less effort to justify a departure from good old percentage calculations.


Making  good alternative process prints is simple in terms of the process if making pictures is your objective.  You need practice and judgement and an eye for a good picture to make really good ones.  All this pointy hat stuff just gets in the way.


Terry








-----Original Message-----
From: Loris Medici <mail at loris.medici.name>
To: 'The alternative photographic processes mailing list' <alt-photo-process-list at lists.altphotolist.org>
Sent: Fri, 23 Jul 2010 13:35
Subject: [alt-photo] Re: dilution of pt/pd


Clay, 

-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org On Behalf Of
Clay Harmon Website
Sent: Friday, July 23, 2010 3:08 PM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Re: dilution of pt/pd

> This thread has been entertaining in a strange, twisted way.

Agree. :)


> Let me see if I have this right:
> 
> 1. The traditional formulas for pt/pd printing are based on percentages
and are not quite chemically balanced. In fact, there is a modest amount of
waste of the
> pt/pd metal salt because of this imbalance.

I've corrected this in a recent message.


> 2. It does not really make much difference in terms of print quality,
because there is an overabundance of metal relative to ferric oxalate with
the traditional formula.
> It works fine, in other words.

Well, I have to see prints to say something about that! ;) Having balanced
formulae doesn't guarantee fine prints, right?


> 3. If you don't want to needlessly flush noble metal salts down the drain,
make a one-time adjustment to your formulation and keep printing.

Yep. :)


> 4. If you don't care and don't want to think about it, and believe a
modest amount of waste in printing lends a sassy and insouciant 19th century
flair to your
> printing practice, just keep doing things the way you always have.

That was good! :) Each to their own, for sure...


> Did I get this right?

Kinda... I thought the actual debate was on the issue of whether talking
about stoichiometry and/or molarity in a public alt-process forum is an
unnecessary "pointy-hat" behaviour and to "over-complicate" things, or not.
Which later evolved to whether the concept of molarity does have a use for
us simple / helpless / poor mortals, or not... But you can't be sure with
Terry! :)


Regards,
Loris.

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