My understanding is that cold chemicals can introduce print quality issues (e.g. graininess). It's not something I've experienced as my darkroom is nice and warm all year round (and I can't define what "cold" is), but it may be something to consider if you get problems.
Thanks Ian, I just re-read Platinum and Palladium Printing by Arentz and he does mention graininess from cold chemistry. I am planning to use a tempering bath while developing to try and remedy this. I have to do the same thing with silver gelatin.
By the way thanks for the PT/PD article, interesting read.
Actually, having a cold darkroom with a heater leads to humidy issues. As you heat the cold air, the humidity goes way down (extremely dry air).
Suggest you get one of the cheap temperature/humidity guages. Light impressions sells one. You can get them elsewhere.
Consider buying one of the non-heating type room humidifiers (evaporative or ultrasonic) -- look in the pharmacy section of any of the bigger stores. I happen to use one by Vicks only because it was cheap and handy.
You may consider humidification of the paper prior to coating
My darkroom humidity never seems to drop below 35% even with the heater going. I guess that's one good thing about an old house, the heat must be passing through the drafty walls and melting the frozen ground keeping the humidity higher
I do have a little evaporative humidifier ready to go and plan to keep it running around 50% humidity, I think Arentz recommends humidifying paper for at least 8 hours before coating. I thought I'd crank it up the night before and coat 12 hours later. Does this seem right?
From whom are you buying your chemicals? Are you buying dry or liquids?
I am buying from B & S, they seem to have a much better reputation for this type of product. I went with the "Back to School Special". What a deal! I also decided to forego the A+B method and am going straight to NA2.
We seem to be at opposite ends of the spectrum, I'm going for the warm tones. Pure palladium and warm potassium oxalate.
For long-term storage, cold is actually good for Ferric Oxalate - it helps retard the conversion from Ferric to Ferrous. Room temperature for working solutions is ideal - between 60f and 80f is good. Palladium is pretty tolerant and doesn't start coming out of solution at temperatures you're likely to experience.
Scott this is good to hear, I don't get into the darkroom as much as I'd like so I was a little worried the Ferric might turn on me before I would get to use much up, I've read the palladium and Na2 last for a very long time, so not too concerned there. As far as the palladium coming out of solution, what kind of temps are you talking about? It is supposed to go into single digit temps over the weekend and I can just see the chemicals sitting on the UPS truck freezing.
When is your article coming out on PT/PD and the Na2 method? I'm looking forward to it.