When printing for the alt process exchange, I found that I had a very hard time getting the prints cleared properly and consistantly. I was throwing out at least half my prints....so I am looking for advice.
Here is what I did in my latest sessions:
I am using freshly mixed Ferric Oxalate (from Artcraft). My silver nitrate is from an unknown source, so that might be suspect. The paper is Arches Platine. I also used Cranes stationary, but had more problems with that. I am not pre-treating the paper in any way. I am using sodium citrate developer without any dichromate additive. I did not think I needed it with a tuned, digital negative.....I am suspecting that might be a problem. I originally used the rinse-clear in citric acid-rinse process prior to toning, but now I am using 3 citric acid baths instead because I thought that might be the problem...it did not seem to help. My toners and fix is per Sandy's recommendation. I save and replenish the developer and throw out the clearing baths and fixer after each session (maybe 300 sq in. of prints). All solutions (ex. silver nitrate and ferric oxalate which use distilled) are from tap water which is close to ph neutral (Lake Michigan water) although my ph strips are pretty hard to read.
The only other things I can think of is to add some amount of potassium dichromate to the developer (how much?) and recalibrate my process or possibly acidify my developer with a little citric acid. I really love the process and the results I get so I want to perfect it as best I can. On the other hand, I really don't want to go through the pain of recalibrating my process unless I really need to.
Thanks for your help -- Mark
I would suspect the following, in order of probability.
1. You definitely need to add some dichromate to the developer. How much depends on the DR of you negative, but even with a very high DR negative (1.8 or higer) you should add some dichromate. For that DR negative I use about 2ml of a 5% potassium dichromate solution per liter of sodium citrate developer.
2. Check the pH of the sodium citrate developer. Best if it is below about 6.5. Add citric acid if above 7.
3. If you are doing a water rinse between the developer and first clearing bath, eliminate it. Something in your water could be causing the pro blem, even if it is not base.
In my experience the print should come out of the developer almost completley clear of stain. If there is a lot of stain at the end of development you may also need to look back at the FO and SN solutions. The FO in particular will go bad and cause some fog after just a month or two from mixing.
Hope this info is useful.
Sandy