There are so many variables (cations, iodide:bromide ratio, age, alcohol type) with the formulas I've tried that it is difficult to say for sure, but I think the low ether/high ethanol mixes produce a much more fragile film that lifts from glass more easily. I can't really say whether the age of the collodion or whether different salt varieties I tried didn't impact the tenacity of the films more than the alcohol:ether ratio, but it seems to me some additional ether needs to be added to collodion USP to give the film adequate strength.
You can't entirely avoid ether in the process since it is already present in the collodion. Ether in combination with strong alcohol is needed to dissolve the nitrated cotton. Either solvent by itself is not sufficient to do so.
But, ether presents a storage problem since the fumes are explosive if concentrated and explosive peroxides will also form in it over time. Most institutional guidelines I've read recommend disposal of opened stocks of ether after 3-6 months. Don't store the ether inside a residence or near ignition sources, and though it is best to keep it cool, in the dark, and in a well-ventilated space, don't use a regular refrigerator to store it since sparks from the motor could set off any fumes that have accumulated inside the box.
The best compromise is to purchase the smallest quantity of ether that you think you'll use in a period of a couple months and not have any excess that you'll have to store. Adding it to the collodion or alcohol will help stabilize it and minimize the rate at which peroxides will form, but the fume hazard still is present and proper storage conditions are necessary for safety. BHT is a chemical additive found in some ether stocks that also helps slow peroxide formation. And keeping oxygen out of the bottle will also help minimize the formation of peroxides. Adding marbles to displace the volume of solution in the storage bottle and/or using a nitrogen blanket at the ether-air interface will also help minimize peroxide formation. Be sure to read the MSDS before using any of these chemicals. You might also want to consult a chemist in regard to the safe handling and storage of all the chemicals used in this process.
There is some anecdotal evidence that denatured alcohol in place of grain alcohol slows the aging of collodion or rejuvenates it, but of course the denatured stuff is toxic and thus more of a hazard than grain alcohol. Another thing to consider is the water content of the alcohol. Collodion must have some water to keep the film open to chemical action, but too much water causes problems. Alcohols with around 4-6% water content (e.g., 190 proof Everclear) seem to work best.
Shorter development times generally promote warmth in the plate color though KCN fixer really warms it up. I prefer the warm color but I don't find the difference personally appealing enough to use that poison. I use ammonium thiosulfate instead and get quick fixing times without the added risk. Addition of some potassium nitrate or silver nitrate to the developer also is supposed to make the plate color more neutral and my casual observation supports that. Some workers add a few drops of solution from the silver sensitizing tank to the developer to get that effect. Reusing developer also promotes the neutral color since some silver comes off the plate during development and ends up in the developer solution.
Sorry to be so long-winded, but the chemicals in the wetplate process should not be handled casually because they do present hazards. The hazards are manageable and getting the proper information is the first step in safely working the process.
Joe
