I am making up my first batch of Pyrocat HD from raw chemicals. As I have experienced in the past with other developers, I am having trouble getting the phenidone to dissolve. I am breaking it up as finely as I can in a mortar and pestle, and adding it as slowly as possible, but the small, undissolved chunks remain. Is there a better way to dissolve the phenidone for this and other developers, and if the small chunks remain, what will this do to the developer?
I've only mixed up one batch of Pyrocat-HD (last year and still working) using warmed water. If I remember correctly the Phenidone went into solution surprisingly easily consider the warnings I'd read, however, the Potassium Carbonate 'B' solution took around 45 minutes to mix the saturated solution, but perhaps I was being overly cautious.
You might try dissolving the Phenidone in a small amount of 90% Isopropyl alcohol before you add it to the other ingredients. I don't understand why you need a mortar and pestle to break up the Phenidone, mine has always been a fluffy powder. Is it old?
I have worked with Pyrocat HD for just over a year now. My best luck with dissolving Phenidone with with a small amount of alcohol. But, then again it has not been much of a problem. I use a magnetic stirrer that has done a great job.
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thanks for the info, guys. I spoke a little too soon, with, as Jim suggested, a little patience and letting my stirrer to it's work, the phenidone did finally dissolve. As to Richard's question, no, the phenidone is new and is not clumped like potassium bromide does. It does, however, stick together in small clumps that I though might dissolve more quickly if I broke them up in a mortar. Which really did not seem to make all that much difference; maybe I should have left it alone!
I wondered about dissolving the phenidone in alcohol, but worry that it might affect properties of the developer unless one of the experts here says otherwise.
Thanks again,
Dan
There is another way. The sulfite ion, in the form of the metabisulfite, serves two purposes in general, but it mostly ensures the synergism between catechol and phenidone in Pyrocat HD. A small amount of ascorbic acid may be used in place of the metabisulfite. Now, the catechol, phenidone and ascorbic acid are all soluble in propylene glycol. Use it as solvent in place of water in the A solution. Somewhere in APUG you will find specific instructions for this recipe.
There is another way. The sulfite ion, in the form of the metabisulfite, serves two purposes in general, but it mostly ensures the synergism between catechol and phenidone in Pyrocat HD. A small amount of ascorbic acid may be used in place of the metabisulfite. Now, the catechol, phenidone and ascorbic acid are all soluble in propylene glycol. Use it as solvent in place of water in the A solution. Somewhere in APUG you will find specific instructions for this recipe.
Pat is right about mixing in glycol.
I am attaching a word file that has mixing directions for most of the pyrocats. Just to clarify, I call Pyrocat-HD that is mixed in glycol and uses ascorbic in place of metabisulfite Pyrocat-HDC, the C simply denoting vitamin C or ascorbic acid. It works almost identically to the regular version but is somewhat easier to mix because ascorbic goes into solution in glycol easier than metabisulfite.
I could easily convert this document to HTML and post it on the web.
That way, people would be able to find it readily via a search engine like Google. I'm not sure if search engines visit this forum.
Alternately, you could put it on Unblinking Eye or somewhere else more in the "public domain". I'm not trying to draw traffic to my site, just be of help. I have nothing to sell anyhow :-)
Originally Posted by sanking
Pat is right about mixing in glycol.
I am attaching a word file that has mixing directions for most of the pyrocats. Just to clarify, I call Pyrocat-HD that is mixed in glycol and uses ascorbic in place of metabisulfite Pyrocat-HDC, the C simply denoting vitamin C or ascorbic acid. It works almost identically to the regular version but is somewhat easier to mix because ascorbic goes into solution in glycol easier than metabisulfite.
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Originally Posted by gainer 
