Re: ferric oxalate
Diana,
It is pretty easy to mix up your own potassium oxalate developer from
combining oxalic acid, potassium carbonate and water. Here is a cut
and pasted recipe from Carl Weese:
2 lbs of Pot Carb with 1.75 lbs oxalic acid to make 1 gallon of
water. 1 lbs = 457
g and 1 gallon = 3.8 l ( top of my head but close enough as it is
just POT
OX).
Mix you Pot Card into cool distilled water; about 1/2 your total
volume.
SLOWLY add your Ox Acid as it WILL BUBBLE!!!!. Add to completion
and top
off with water to make final volume.
Clay
On Nov 10, 2008, at 5:02 PM, Diana Bloomfield wrote:
Thanks, Brian. I'm gonna have to go get that book now.
I almost always use palladium with Na2 for any contrast.
I noticed too-- not much info on the web, but I need to get the
second edition of Arentz's book.
Although I was in a panic some months ago, when I was getting ready
for a show-- and I ran out of developer right at the 11th hour. I
typically use potassium oxalate-- and, naturally, I'm 1,000 miles--
at least-- from anybody who sells it. And my platinum printer
friend here was out of town-- so, I did find this little recipe for
a sodium acetate developer on the web-- a weird mix of distilled
white vinegar and sodium bicarbonate-- all readily available at my
local grocery store. I had to go buy this stuff by the gallon/
pound-- and felt like a Mr. Wizard mixing up this concoction-- but
it worked like a charm. Definitely a cooler (less warm) look in the
final print, but it worked fine. And the prints still look good. :)
On Nov 10, 2008, at 5:48 PM, Brian Pawlowski wrote:
Thanks Brian. So that's it-- nothing else added? I was heating the
water, but maybe it should be hotter.
I do like the Chubby Checker idea, though-- I'll try that and-- you
know-- dance like I did last summer.
So, what Pt/Pd process for contrast will you use?
That affects the solution. Na2 process uses Ferric Oxalate in water
as the sensitizer, Na2 contrast agent (smidgen), and Palladium sol'n
(will *not* work with Platinum!).
Wow - I was trying to find a simple web page that describes the
Na2 contrast method for Palladium, but haven't found anything
I can fwd. The other widely used method is the ratio method,
and there is a pretty good write up here:
http://www.bostick-sullivan.com/articles/platprintsimple.html
This is all well described in Arentz Pt/Pd *Second* Edition...
I'm a little surprised there is not more readily available canned
info on the web that summarizes this... Odd.
Boy, there are other methods than Na2 and ratio methods out there
(Ware's approach, hydorgen peroxide Rudiak mentions, and use
of dichromate in developer for contrast control - all of these
are also covered in Arentz bible...)
Wheeee!
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