RE: Potassium Oxalate developer for Platinum printing

I print in kallitype and Pt./Pd. with both potassium oxalate and
sodium citrate developers. To keep either developer working well I
recommend.

1. Always mix with distilled water.

2. Replenish at the rate of a minimum of about 50 ml of fresh
solution for every 8X10 print that goes through the solution.

3. Check the pH frequently to make sure it stays acidic. If the
solution becomes base add oxalic acid (to potassium oxalate) or
citric acid (to sodium citrate) to return the solution to acidic
condition.

If you do the above the developer should last a very long time.

Sandy

>Cor,
>I do not print pure Pt, but in my experience of palladium/platinum
>mix the developer lasts forever. I just replenish what was is lost
>in a development session. Do keep your developer acidic, as it will
>fog the paper otherwise. If you use buffered papers that might
>require even more oxalic acid replenishment. I keep mine developer
>with some undissolved acid on the bottom.
>Le tus know how you solved your fogging problem.
>Marek, Houston
>
>>From: Eric Neilsen <e.neilsen@worldnet.att.net>
>>Reply-To: alt-photo-process-l@usask.ca
>>To: alt-photo-process-l@usask.ca
>>Subject: RE: Potassium Oxalate developer for Platinum printing
>>Date: Mon, 24 Apr 2006 20:34:59 -0500
>>
>>Cor, Your developer will hold onto a portion of your coated area that was
>>exposed and not part of the print. This coated and very slightly excited
>>area will become part of that 500ml; which seems really skimpy to me by the
>>way. There are also buffers in the papers that can adversely effect your
>>developer. While you may only need 500ml to cover your paper, I'd advise you
>>to use a larger amount as a stock solution. If the cost of Potassium Oxalate
>>powder is high in your area, I would make it from Potassium Carbonate and
>>Oxalic acid. Pour out the amount need to develop your print, and after pour
>>it back.
>>
>>You can also use Oxalic acid to keep your developer on the acid side of
>>life. You may also find that exposing your developer to UV light and
>>letting it sit, will allow you to remove the excess metals from your
>>developer. The greenish quality is not a problem. Single shot eliminates the
>>chance of fog due to removed components from previous prints, but I don't
>>find it necessary.
>>
>>You can use a lower concentration of Pot ox but you run the risk of graining
>>up your prints. You will also need slightly more exposure.
>>
>>I have only tried brush development a few times, but I would look into a
>>good even pour ,just like for coating the sensitizer, and a quick even
>>dispersal of the coating, perhaps even by using a rod.
>>
>>Eric
>>
>>Eric Neilsen Photography
>>4101 Commerce Street
>>Suite 9
>>Dallas, TX 75226
>>http://e.neilsen.home.att.net
>>http://ericneilsenphotography.com
>>
>>> -----Original Message-----
>>> From: Breukel, C. (HKG) [mailto:C.Breukel@lumc.nl]
>>> Sent: Monday, April 24, 2006 5:52 AM
>>> To: alt-photo-process-l@usask.ca
>>> Subject: Potassium Oxalate developer for Platinum printing
>>>
>>> (maybe you'll see this message for the second time, I did not see it
>>> appear..)
>>>
>>> Hi,
>>>
>>>
>>> I have been using a 25% solution of Potassium Oxalate as my developer
>>> for Platinum printing (no Palladium added), and to my surprise this
>>> developer went "off" rather quikly. That is: in the 500ml I started with
>>> I could process only 5-7 8*10 images (did not keep exact count). My last
>>> print showed veiled highlights, which did not want to clear, and the
>>> PotOx solution is now very murky with a greenish brown strong colour.
>>>
>>> I looked into dome books as well as in the archives, and the things I
>>> find are contradicting (no surprise I guess). Crawford (and Farber who I
>>> think quotes Crawford) claims that the developer keeps indefinitely, and
>>> has only be toped up with fresh developer to make up for the loss. It
>>> actually gets better when it's more used. James states about the same,
>>> although he says that there is an end to the live of the developer.
>>> Jeffrey Mathias advices to use the developer single shot, reusing will
>> > cause fog..
>>>
>>> Single shot seems a bit wasteful, as well environmental unfriendly with
>>> this toxic chemical, OTOH 6 8*10 prints with half a litre isn't exactly
>>> economical either, plus the ruining of the last print.
>>>
>>> Can one use a lower concentration of PotOX, develop longer and discard
>>> it afterwards?
>>>
>>> I did try brush development with glycerol: PotOx 1:1, but I wasn't very
>>> successful with that, got a lot of developer lines, will brush
>>> development also work with FO, I have only read about it connection with
>>> AFO.
>>>
>>> Comments or suggestions/
>>>
>>> Thanks!
>>>
>>>
>>> Cor
Received on Tue Apr 25 09:14:25 2006