Be sure you follow the specific recipe for the glycol mix, as sodium sulfite is not soluble in glycol. I think you can get it ready mixed or at least in a kit from PF. Pyrocat made with pyrogallol is an interesting experiment as well. Use 2/3 as much pyrogallol as you would of catechol. That's only because it has 3 OH groups instead of the 2 of catechol.
I think the Pyrocats are better for use in stand or semi-stand as far as grain, etc. than PMK. Using pyrogallol in the recipe for Pyrocat PC or MC gives IMO the color of PMK with the other
qualities of Pyrocat.
I have not had the overall stain problem with PMK because I never did the stain intensification bit, except possibly once. BTW, I wrote that article for what is now Photo Techniques. You can order a reprint of it. Search for "More Pyrotechnics" on the Photo Techniques site.
I was hoping Sandy King would reply to this thread, as he is the developer of the Pyrocat family of developers. In his absence, here is a response he posted in a thread about staining developers and VC papers:
"There are several potential reasons to use a staining developer.
1. high acutance
2. grain masking
3. capability of building higher contrast for alternative processes
4. highlight compensation
The first three of this reasons are valid for all printing processes, graded and VC silver papers, and for alternative printing. Highlight compensation only applies to VC silver papers, and then only if you do not use a VC filter #3.5 or greater (or dial in the equivalent magenta filtration with a color head).
The original poster specified that he was NOT interested in results relating to VC papers, so only points 1-3 apply. I suspect that PMK and Pyrocat will be very similar regarding the first three points. (I am a long-time PMK user, and haven't experimented with Pyrocat. My experience is that PMK is high-acutance, and the grain-masking is effective for medium format and larger; I find PMK too grainy for 35mm. Many posts indicate that Pyrocat shares these characteristics, although I don't know about its use on 35mm. Also, one of the reasons for developing Pyrocat was the known oxidation problems of PMK in rotary processing, which is not recommended. )
Here are a couple more interesting facts. TEA can be used as PMK B in place of the Kodalk. It seems to be the one organic base Hutchings didn't try for his excellent book. The only ingredient of PMK that is not soluble in propylene glycol (if you excuse the used of a little TEA and water to separate the Metol base from its H2SO4) is the sulfite, and a little ascorbic acid will substitute for that. In that case, PMK A in glycol is not greatly diferent from Pyrocat MC A with pyrogallol instead of pyrocatechin.
I would not be surprised if you could substitute p-aminophenol base for the Metol in the glycol mix. It is readilly soluble. It is probably the easiest of the Pyrocat formulas to make. Glycol, catechol, p-aminophenol base, ascorbic acid and mix. Warming helps the mixing, as the organic solvents do not have the degree of brownian motion (My theory) as water. PF can supply the p-aminophenol base. Phenidone is another option, which would make the glycol form of Pyrocat HD. It also is easy to mix.
There's nothing like a tank of nitrogen gas to take the anxiety out of developing negs in pmk.
I'm an happy and satisfied user of Pyrocat MC and this suggestion to make a sort of "Pyrogallol MC" is very interesting.
Originally Posted by gainer
If I understand well you have to mix, for the Pyrogallol formula, the same amount of catechol + 2/3 of the weight for Pyrogallol formula.
At the end for one liter of stock solution, as the original formula for Pyrocat MC called for 100 grams of Catechol, it will be 150 grams of pyrogallol to mix Pyrogallol MC.
Am I right Pat?
If understand all correctly, For graded papers I should see no difference between finished prints using either PMK or Pyrocat-HD. The differences are all in the process.
" If understand all correctly, For graded papers I should see no difference between finished prints using either PMK or Pyrocat-HD. The differences are all in the process." rob
Rob, you will see a large difference in the shdow values. Try both to see how they look, then please write back and let us know which types of shadows you enjoy most. After having done both, my hunch is that it will be pyrocat. tim
What would be the advantage of mixing up PMK in glycol? The shelf life is already astounding. Please correct me if I'm wrong, but I understood that the use of glycol was to enhance shelf life of the stock solution. PMK is already near-immortal with plain distilled water. :)
Originally Posted by gainer
You've given me lots of interesting ideas to try with your posts by the way - please continue :)
This is true, However, you can use PMK in a rotary processor quite successfully with a couple of changes to the process - I process FP4+ in a Jobo 1521 tank with the 1509N reel all the time. I have had to make 2 adjustments to get this to work consistently.
Originally Posted by palewin
First, use a lot of developer - for me a minimum of 500ml - this is the most I can put in my tank. Second, break up the development time into more than one batch - For example, if my development time is 10 minutes, I'll mix up 2 500ml batches of PMK, start the development with the first one, then after 5 minutes, dump that one out and put in the second batch for the remainder of the time - I find that at 70 deg F, I get the best results if I don't let a batch go for more than 5 -5 1/2 minutes.
Finally, - I add a very small amount of EDTA to promote even development - this is actually specific to my particular tank and reel - people using the expert probably drums don't need to do this - I got this info from the latest edition of "The Book of Pyro"
I also don't use the after-bath. It's interesting that even though Gordon no longer recommends the after-bath, it's still in the latest edition of his book.
I also don't see a lot of general stain on my negatives. In fact, when I got some Pyrocat-HD, I went out and shot multiple negatives of the same subject, then developed some in PMK and some in Pyrocat-HD. When I compare the negatives visually, my PMK negatives don't appear to have any more general stain than the Pyrocat negatives do - of course since I don't have a densitometer and I don't do alternative processes, it is entirely possible that there is more general stain, but I just don't see it visually or when I'm printing.