From: Sandy King (sanking@clemson.edu)
Date: 07/17/02-07:59:24 AM Z
Cor wrote:
>
>I seem to recall that this developer isn't very stable (the mixed stocks
>I mean).
>Is this also your experience? And if the Pyrocat stock goes "bad",
>you'll notice it by it's colour change?
>
>PMK Pyro is reported to be very stable (stocks), so that is an advantage
>for a low volume shooter like me.
>
>Best,
>
>Cor
-- You may have confused reports about the stability of ABC+/Rollo Pyro with Pyrocat-HD. As regards ABC+/Rollo Pyro I have heard quite a number of negative reports about the stability of the stock solutions, or more specifically, stock solution A. The issue is that that the developer appears to lose a lot of its energy after a few months of storage. The likely culprit is ascorbic acid, which is known to go bad in certain kinds of stock solutions. Just look at all the discussion about this problem with regard to Xtol. As for Pyrocat-HD I have suggested in various places that the stability of Stock Solution A, when the formula contains phenidone, is not as great as the stability Stock Solution A of PMK, which as we know can last for years. When I initially made this suggestion it was based on theory. However, after working with Pyrocat-HD for a number of years I can state as a fact that Stock Solution A, with Phenidoine, is good for up to 6 months, with proper storage. Not as good as PMK but as good or better than most all other developers. With metol in place of phenidone stability is even better. Sandy King
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