[alt-photo] Re: Zia standard solutions

[Christina Anderson]

Jalo and others,
(Oh my, I'm approaching my ten-post limit for the day)
Jalo's point brought up a topic I have been meaning to ask.  If Jalo just uses the 25ml and adds the chemicals, he essentially has just diluted the solution by a very teeny amount.  Years ago I read about diluting the combined pt/pd solution 50% with water and double coating. This was to get around the very absorbent Rives BFK situation.

My question is this:  has anyone diluted the more expensive precious metal solutions with water as a general practice, either to save $$, or to deal with absorbent papers, or whatnot? I know that if the ratio of ferric to pt/pd goes awry, you get a weak print (seen that in workshops), but given the ratios staying the same, maybe even a 10% or 20% addition of water to the total mix might be possible as general practice? Just wondering if anyone does this, and if so, at what point does it not work.  The person in question was double coating so it wasn't going to affect the total amount of pt/pd on the paper, so I am asking about lessening that total amount.
Chris



Christina Z. Anderson
christinaZanderson.com

On Jul 20, 2010, at 9:47 AM, Christina Anderson wrote:

> Jalo,
> Being consistent with what you do is the most important thing. For instance, I used to measure out my dichromate with a gram scale to get exactly a 15% and put it in 75ml water and then fill to 100ml.  Now I just add 2 tsp. of dichromate to 100ml--quick and easy and close enough to a 15%, but because I use it that way all the time and have calibrated with that dilution, I have consistency.  But gum is more forgiving than other processes.  When I mix my own palladium solutions with the powdered palladium, I measure exact and don't sneeze or breathe. Once I was mixing $1000 worth of palladium powder for a class and I was so freaked I would spill and then have to foot the bill....
> Chris
> 
> 
> Christina Z. Anderson
> christinaZanderson.com
> 
> 
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